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Asbaghi O, Shimi G, Hosseini Oskouie F, Naseri K, Bagheri R, Ashtary-Larky D, Nordvall M, Rastgoo S, Zamani M, Wong A. The effects of conjugated linoleic acid supplementation on anthropometrics and body composition indices in adults: a systematic review and dose-response meta-analysis. Br J Nutr 2024; 131:406-428. [PMID: 37671495 DOI: 10.1017/s0007114523001861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
Prior meta-analytic investigations over a decade ago rather inconclusively indicated that conjugated linoleic acid (CLA) supplementation could improve anthropometric and body composition indices in the general adult population. More recent investigations have emerged, and an up-to-date systematic review and meta-analysis on this topic must be improved. Therefore, this investigation provides a comprehensive systematic review and meta-analysis of randomised controlled trials (RCT) on the impact of CLA supplementation on anthropometric and body composition (body mass (BM), BMI, waist circumference (WC), fat mass (FM), body fat percentage (BFP) and fat-free mass (FFM)) markers in adults. Online databases search, including PubMed, Scopus, the Cochrane Library and Web of Science up to March 2022, were utilised to retrieve RCT examining the effect of CLA supplementation on anthropometric and body composition markers in adults. Meta-analysis was carried out using a random-effects model. The I2 index was used as an index of statistical heterogeneity of RCT. Among the initial 8351 studies identified from electronic databases search, seventy RCT with ninety-six effect sizes involving 4159 participants were included for data analyses. The results of random-effects modelling demonstrated that CLA supplementation significantly reduced BM (weighted mean difference (WMD): -0·35, 95 % CI (-0·54, -0·15), P < 0·001), BMI (WMD: -0·15, 95 % CI (-0·24, -0·06), P = 0·001), WC (WMD: -0·62, 95% CI (-1·04, -0·20), P = 0·004), FM (WMD: -0·44, 95 % CI (-0·66, -0·23), P < 0·001), BFP (WMD: -0·77 %, 95 % CI (-1·09, -0·45), P < 0·001) and increased FFM (WMD: 0·27, 95 % CI (0·09, 0·45), P = 0·003). The high-quality subgroup showed that CLA supplementation fails to change FM and BFP. However, according to high-quality studies, CLA intake resulted in small but significant increases in FFM and decreases in BM and BMI. This meta-analysis study suggests that CLA supplementation may result in a small but significant improvement in anthropometric and body composition markers in an adult population. However, data from high-quality studies failed to show CLA's body fat-lowering properties. Moreover, it should be noted that the weight-loss properties of CLA were small and may not reach clinical importance.
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Affiliation(s)
- Omid Asbaghi
- Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ghazaleh Shimi
- Department of Cellular and Molecular Nutrition, Faculty of Nutrition Science and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fatemeh Hosseini Oskouie
- Department of Clinical Nutrition and Dietetics, Faculty of Nutrition and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kaveh Naseri
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Reza Bagheri
- Department of Exercise Physiology, University of Isfahan, Isfahan, Iran
| | - Damoon Ashtary-Larky
- Nutrition and Metabolic Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Michael Nordvall
- Department of Health and Human Performance, Marymount University, Arlington, VA, USA
| | - Samira Rastgoo
- Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Cellular and Molecular Nutrition, Faculty of Nutrition Science and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Zamani
- Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Alexei Wong
- Department of Health and Human Performance, Marymount University, Arlington, VA, USA
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Florez CM, Prather J, Miller D, Vargas A, Soto B, Harrison A, Tinsley G, Taylor L. The Effects of Two Servings of a Thermogenic Supplement on Metabolism, Hemodynamic Variables, and Mood State Outcomes in Young Overweight Adults. Cureus 2024; 16:e54484. [PMID: 38516475 PMCID: PMC10954375 DOI: 10.7759/cureus.54484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/19/2024] [Indexed: 03/23/2024] Open
Abstract
Introduction We examined if acute ingestion of a novel thermogenic supplement influences resting energy expenditure (REE), mood, and hemodynamic function. Methods Forty-six adults completed this randomized, placebo-controlled, double-blind, crossover study. Participants underwent two conditions: placebo (PL) and treatment (TX) containing 300 mg of caffeine and 3 g of acetyl-L-carnitine. REE, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and mood states were assessed at baseline and 30, 60, and 120 minutes post-ingestion. Data were analyzed using repeated measures analysis of variance. Results A significant condition-by-time interaction was observed for REE. At the 30-, 60-, and 120-minute post-ingestion timepoints, REE was 202 ± 26, 238 ± 40, and 209 ± 29 kcal/d greater in the TX condition compared to PL. No significant differences were observed for SBP and HR but a significant interaction indicated that DBP was elevated at 30 minutes in the TX vs. PL, though values remained within normal ranges. Significant interactions were observed for perceived alertness, concentration, energy, and focus, with increases in TX. Conclusion These data provide evidence that acute consumption of the thermogenic dietary supplement OxyShred (EHPlabs, Salt Lake City, Utah, USA) stimulates increases in REE that are sustained for ≥ two hours, along with increasing perceived alertness, concentration, energy, and focus. Changes in hemodynamic function are minimal and within normal ranges.
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Affiliation(s)
| | - Jessica Prather
- Human Performance Lab, University of Mary Hardin-Baylor, Belton, USA
| | - Dylon Miller
- Human Performance Lab, University of Mary Hardin-Baylor, Belton, USA
| | - Amie Vargas
- Human Performance Lab, University of Mary Hardin-Baylor, Belton, USA
| | - Bella Soto
- Human Performance Lab, University of Mary Hardin-Baylor, Belton, USA
| | - Abby Harrison
- Human Performance Lab, University of Mary Hardin-Baylor, Belton, USA
| | - Grant Tinsley
- Kinesiology & Sport Management, Texas Tech University, Lubbock, USA
| | - Lem Taylor
- Physiology and Nutrition, University of Mary Hardin-Baylor, Belton, USA
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Jamka M, Czochralska-Duszyńska A, Mądry E, Lisowska A, Jończyk-Potoczna K, Cielecka-Piontek J, Bogdański P, Walkowiak J. The Effect of Conjugated Linoleic Acid Supplementation on Densitometric Parameters in Overweight and Obese Women-A Randomised Controlled Trial. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1690. [PMID: 37763810 PMCID: PMC10537680 DOI: 10.3390/medicina59091690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 09/07/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023]
Abstract
Background and Objectives: Conjugated linoleic acid (CLA) can improve bone health in animals, yet the effects on humans have not been consistent. Therefore, this parallel randomised controlled trial aimed to assess the effect of CLA supplementation on bone mineral density (BMD) and content (BMC) in overweight or obese women. Materials and Methods: The study population included 74 women who were divided into the CLA (n = 37) and control (n = 37) groups. The CLA group received six capsules per day containing approximately 3 g of cis-9, trans-11 and trans-10, cis-12 CLA isomers in a 50:50 ratio. The control group received the same number of placebo capsules that contained sunflower oil. BMC and BMD at total body, lumbar spine (L1-L4), and femoral neck were measured before and after a three-month intervention. Results: The comparison of BMC and BMD for the total body, lumbar spine (L1-L4), and femoral neck before and after the intervention showed no differences between the groups. However, a within-group analysis demonstrated a significant increase in BMC (p = 0.0100) and BMD (p = 0.0397) at lumbar spine (L1-L4) in the CLA group. Nevertheless, there were no significant differences between the CLA and placebo groups in changes in all analysed densitometric parameters. Conclusions: Altogether, three-month CLA supplementation in overweight and obese women did not improve bone health, although the short intervention period could have limited our findings, long-term intervention studies are needed. The study protocol was registered in the German Clinical Trials Register database (ID: DRKS00010462, date of registration: 4 May 2016).
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Affiliation(s)
- Małgorzata Jamka
- Department of Pediatric Gastroenterology and Metabolic Diseases, Poznan University of Medical Sciences, Szpitalna Str. 27/33, 60-572 Poznań, Poland;
| | - Agata Czochralska-Duszyńska
- Department of Physiology, Poznan University of Medical Sciences, Święcickiego Str. 6, 61-781 Poznań, Poland; (A.C.-D.); (E.M.)
| | - Edyta Mądry
- Department of Physiology, Poznan University of Medical Sciences, Święcickiego Str. 6, 61-781 Poznań, Poland; (A.C.-D.); (E.M.)
| | - Aleksandra Lisowska
- Department of Pediatric Diabetes, Auxology and Obesity, Poznan University of Medical Sciences, Szpitalna Str. 27/33, 60-572 Poznań, Poland;
| | - Katarzyna Jończyk-Potoczna
- Department of Pediatric Radiology, Poznan University of Medical Sciences, Szpitalna Str. 27/33, 60-572 Poznań, Poland;
| | - Judyta Cielecka-Piontek
- Department of Pharmacognosy and Biomaterials, Poznan University of Medical Sciences, Rokietnicka Str. 3, 60-806 Poznań, Poland;
| | - Paweł Bogdański
- Department of Treatment of Obesity, Metabolic Disorders and Clinical Dietetics, Poznan University of Medical Sciences, Szamarzewskiego Str. 84, 60-569 Poznań, Poland;
| | - Jarosław Walkowiak
- Department of Pediatric Gastroenterology and Metabolic Diseases, Poznan University of Medical Sciences, Szpitalna Str. 27/33, 60-572 Poznań, Poland;
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Putera HD, Doewes RI, Shalaby MN, Ramírez-Coronel AA, Clayton ZS, Abdelbasset WK, Murtazaev SS, Jalil AT, Rahimi P, Nattagh-Eshtivani E, Malekahmadi M, Pahlavani N. The effect of conjugated linoleic acids on inflammation, oxidative stress, body composition and physical performance: a comprehensive review of putative molecular mechanisms. Nutr Metab (Lond) 2023; 20:35. [PMID: 37644566 PMCID: PMC10466845 DOI: 10.1186/s12986-023-00758-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 08/25/2023] [Indexed: 08/31/2023] Open
Abstract
Conjugated linoleic acids (CLAs) are polyunsaturated fatty acids primarily found in dairy products and ruminant animal products such as beef, lamb, and butter. Supplementation of CLAs has recently become popular among athletes due to the variety of health-promoting effects, including improvements in physical performance. Preclinical and some clinical studies have shown that CLAs can reduce inflammation and oxidative stress and favorably modulate body composition and physical performance; however, the results of previously published clinical trials are mixed. Here, we performed a comprehensive review of previously published clinical trials that assessed the role of CLAs in modulating inflammation, oxidative stress, body composition, and select indices of physical performance, emphasizing the molecular mechanisms governing these changes. The findings of our review demonstrate that the effect of supplementation with CLAs on inflammation and oxidative stress is controversial, but this supplement can decrease body fat mass and increase physical performance. Future well-designed randomized clinical trials are warranted to determine the effectiveness of (1) specific doses of CLAs; (2) different dosing durations of CLAs; (3) various CLA isomers, and the exact molecular mechanisms by which CLAs positively influence oxidative stress, inflammation, body composition, and physical performance.
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Affiliation(s)
- Husna Dharma Putera
- Department of Surgery, Faculty of Medicine, Lambung Mangkurat University, Banjarmasin, South Kalimantan, Indonesia
| | - Rumi Iqbal Doewes
- Faculty of Sport, Universitas Sebelas Maret, Jl. Ir. Sutami, 36A, Kentingan, Surakarta, Indonesia
| | - Mohammed Nader Shalaby
- Biological Sciences and Sports Health Department, Faculty of Physical Education, Suez Canal University, Ismailia, Egypt
| | - Andrés Alexis Ramírez-Coronel
- Azogues Campus Nursing Career, Health and Behavior Research Group (HBR), Psychometry and Ethology Laboratory, Catholic University of Cuenca, Azogues, Ecuador
| | - Zachary S Clayton
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Walid Kamal Abdelbasset
- Department of Health and Rehabilitation Sciences, College of Applied Medical Sciences, Prince Sattam Bin Abdulaziz University, Al Kharj, Saudi Arabia
- Department of Physical Therapy, Kasr Al-Aini Hospital, Cairo University, Giza, Egypt
| | - Saidmurodkhon S Murtazaev
- Department of Therapeutic Pediatric Dentistry, Dean of the Faculty of International Education, Tashkent State Dental Institute, Tashkent, Uzbekistan
- Department of Scientific Affairs, Samarkand State Medical University, Amir Temur Street 18, Samarkand, Uzbekistan
| | - Abduladheem Turki Jalil
- Medical Laboratories Techniques Department, Al-Mustaqbal University College, Hilla, Babylon, 51001, Iraq
| | - Pegah Rahimi
- Department of Clinical Pharmacy, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran
| | - Elyas Nattagh-Eshtivani
- Social Development and Health Promotion Research Center, Gonabad University of Medical Sciences, Gonabad, Iran
| | - Mahsa Malekahmadi
- Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Naseh Pahlavani
- Health Sciences Research Center, Torbat Heydariyeh University of Medical Sciences, Torbat-e Heydariyeh, Iran.
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Liang CW, Cheng HY, Lee YH, Liou TH, Liao CD, Huang SW. Effects of conjugated linoleic acid and exercise on body composition and obesity: a systematic review and meta-analysis. Nutr Rev 2023; 81:397-415. [PMID: 36048508 DOI: 10.1093/nutrit/nuac060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
CONTEXT Conjugated linoleic acid (CLA) has been reported to have anti-obesity and antidiabetic effects. However, the benefits of CLA combined with exercise remain unclear, and studies report conflicting results. OBJECTIVE A systematic review and meta-analysis were performed to investigate the synergistic effect of CLA and exercise on body composition, exercise-related indices, insulin resistance, and lipid profiles; and of the safety of CLA supplements. DATA SOURCES In October 2021, the PubMed, Embase, and Cochrane Library databases were searched for reports on clinical trials of the combined intervention of CLA and exercise. DATA EXTRACTION A total of 18 randomized controlled trials and 2 crossover trials were included. The methodological quality assessment was performed using the revised Cochrane risk-of-bias tool. Pooled effect sizes were reported as standardized mean difference (SMD) for continuous data and risk ratio for dichotomous data with their corresponding 95% confidence intervals (CIs). Heterogeneity was tested using the I2 statistic. DATA ANALYSIS The combination of CLA and exercise resulted in significantly decreased body fat (SMD, -0.42 [95%CI, -0.70, -0.14]; P = 0.003; I2 = 65) and insulin resistance (SMD, -0.25 [95%CI, -0.44, -0.06]; P = 0.01; I2 = 0) than did exercise alone. In subgroup analysis, the following factors were associated with significant outcomes: (1) body mass index ≥25 kg/m2; (2) female sex; (3) follow-up time >4 weeks; and (4) intervention duration >4 weeks. Nevertheless, supplementation with CLA during exercise programs was not effective for body-weight control, exercise performance enhancement, or lipid-profile improvement. CLA in combination with exercise did not result in a higher risk of adverse events (risk ratio, 1.32 [95%CI, 0.94-1.84]; P > 0.05; I2 = 0). CONCLUSION CLA combined with exercise is generally safe and can lower body fat and insulin resistance but does not reduce body weight, enhance exercise performance, or improve lipid profiles.
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Affiliation(s)
- Chun-Wei Liang
- are with the School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Hsiao-Yi Cheng
- are with the School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yu-Hao Lee
- are with the Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.,are with the Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Tsan-Hon Liou
- are with the Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.,are with the Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chun-De Liao
- are with the Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.,is with the Master Program in Long-Term Care, College of Nursing, Taipei Medical University, Taipei, Taiwan
| | - Shih-Wei Huang
- are with the Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.,are with the Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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6
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Rastgoo S, Shimi G, Shiraseb F, Karbasi A, Ashtary-Larky D, Yousefi M, Golalipour E, Asbaghi O, Zamani M. The effects of conjugated linoleic acid supplementation on inflammatory cytokines and adipokines in adults: A GRADE-assessed systematic review and dose-response meta-analysis. Front Immunol 2023; 14:1092077. [PMID: 36911696 PMCID: PMC9992184 DOI: 10.3389/fimmu.2023.1092077] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/02/2023] [Indexed: 02/25/2023] Open
Abstract
Background and aims Many studies have investigated the effect of conjugated linoleic acid (CLA) supplementation on inflammatory cytokines and adipokines. However, the results of these studies are not consistent. Therefore, this systematic review and meta-analysis were designed to comprehensively evaluate the effect of CLA supplementation on inflammatory cytokines and adipokines. Methods Randomized controlled trials (RCTs) examining the effects of CLA supplementation on C-reactive protein (CRP), interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), adiponectin, and leptin, published up to March 2022, were identified through PubMed, SCOPUS, and ISI Web of Science databases. A random-effects model was used to calculate weighted mean differences (WMDs) with 95% confidence intervals (CI) for 42 studies that included 1,109 participants. Results Findings from 42 studies with 58 arms indicated that CLA supplementation significantly decreased IL-6 and TNF-α levels and also slightly increased CRP levels. However, adiponectin and leptin levels did not change after CLA supplementation. A subgroup analysis found that CLA supplementation reduced adiponectin and leptin in women. Conclusion Our results demonstrated that CLA supplementation increased CRP levels and decreased TNF-α and IL-6 levels. Therefore, it seems that CLA can have both proinflammatory and anti-inflammatory roles. Systematic review registration https://www.crd.york.ac.uk/prospero/, identifier (CRD42022331110).
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Affiliation(s)
- Samira Rastgoo
- Department of Cellular and Molecular Nutrition, Faculty of Nutrition Science and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ghazaleh Shimi
- Department of Cellular and Molecular Nutrition, Faculty of Nutrition Science and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Farideh Shiraseb
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Ashkan Karbasi
- Department of Clinical Biochemistry, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Damoon Ashtary-Larky
- Nutrition and Metabolic Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mohsen Yousefi
- Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Elnaz Golalipour
- Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Omid Asbaghi
- Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Zamani
- Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
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7
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Asbaghi O, Ashtary-larky D, Naseri K, Saadati S, Zamani M, Rezaei Kelishadi M, Nadery M, Doaei S, Haghighat N. The effects of conjugated linoleic acid supplementation on lipid profile in adults: A systematic review and dose-response meta-analysis. Front Nutr 2022; 9:953012. [PMID: 36438733 PMCID: PMC9682566 DOI: 10.3389/fnut.2022.953012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/28/2022] [Indexed: 09/11/2023] Open
Abstract
Background The findings of trials investigating the effect of conjugated linoleic acid (CLA) administration on lipid profile are controversial. This meta-analysis of randomized controlled trials (RCTs) was performed to explore the effects of CLA supplementation on lipid profile. Methods Two authors independently searched electronic databases including PubMed, Web of Science, and Scopus until March 2022, in order to find relevant RCTs. The random effects model was used to evaluate the mean and standard deviation. Results In total, 56 RCTs with 73 effect sizes met the inclusion criteria and were eligible for the meta-analysis. CLA supplementation significantly alter triglycerides (TG) (WMD: 1.76; 95% CI: -1.65, 5.19), total cholesterols (TC) (WMD: 0.86; 95% CI: -0.42, 2.26), low-density lipoprotein cholesterols (LDL-C) (WMD: 0.49; 95% CI: -0.75, 2.74), apolipoprotein A (WMD: -3.15; 95% CI: -16.12, 9.81), and apolipoprotein B (WMD: -0.73; 95% CI: -9.87, 8.41) concentrations. However, CLA supplementation significantly increased the density lipoprotein cholesterol (HDL-C) (WMD: -0.40; 95% CI: -0.72, -0.07) concentrations. Conclusion CLA supplementation significantly improved HDL-C concentrations, however, increased concentrations of TG, TC, LDL-C, apolipoprotein A, and apolipoprotein B. Systematic review registration https://www.crd.york.ac.uk/prospero/#recordDetails, identifier: CRD42022331100.
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Affiliation(s)
- Omid Asbaghi
- Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Damoon Ashtary-larky
- Nutrition and Metabolic Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Kaveh Naseri
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Saeede Saadati
- Department of Medicine, School of Clinical Sciences, Monash University, Melbourne, VIC, Australia
| | - Mohammad Zamani
- Department of Clinical Nutrition, School of Nutritional sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahnaz Rezaei Kelishadi
- Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Maryam Nadery
- Department of Dietetics and Nutrition, Robert Stempel College of Public Health & Social Work, Florida International University, Miami, FL, United States
| | - Saeid Doaei
- Reproductive Health Research Center, Department of Obstetrics and Gynecology, Al-Zahra Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Neda Haghighat
- Laparoscopy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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8
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The Role of Bovine and Non-Bovine Milk in Cardiometabolic Health: Should We Raise the "Baa"? Nutrients 2022; 14:nu14020290. [PMID: 35057470 PMCID: PMC8780791 DOI: 10.3390/nu14020290] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/01/2022] [Accepted: 01/06/2022] [Indexed: 12/14/2022] Open
Abstract
Although causality is yet to be confirmed, a considerable volume of research has explored the relationships between cow milk consumption, type II diabetes, and cardiovascular disease. Contrastingly, it has not been comprehensively examined whether milk of non-bovine origin can provide cardiometabolic protection. This narrative review outlines the marked differences in macronutrient composition, particularly protein and lipid content, and discusses how whole milk product (and individual milk ingredients) from different species could impact cardiometabolic health. There is some data, although primarily from compositional analyses, animal studies, and acute clinical trials, that non-bovine milk (notably sheep and goat milk) could be a viable substitute to cow milk for the maintenance, or enhancement, of cardiometabolic health. With a high content of medium-chain triglycerides, conjugated linoleic acid, leucine, and essential minerals, sheep milk could assist in the prevention of metabolic-related disorders. Similarly, albeit with a lower content of such functional compounds relative to sheep milk, goat and buffalo milk could be plausible counterparts to cow milk. However, the evidence required to generate nutritional recommendations for ‘non-bovine milk’ is currently lacking. Longer-term randomised controlled trials must assess how the bioactive ingredients of different species’ milks collectively influence biomarkers of, and subsequently incidence of, cardiometabolic health.
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9
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Bessell E, Maunder A, Lauche R, Adams J, Sainsbury A, Fuller NR. Efficacy of dietary supplements containing isolated organic compounds for weight loss: a systematic review and meta-analysis of randomised placebo-controlled trials. Int J Obes (Lond) 2021; 45:1631-1643. [PMID: 33976376 DOI: 10.1038/s41366-021-00839-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 04/07/2021] [Accepted: 04/26/2021] [Indexed: 02/04/2023]
Abstract
BACKGROUND/OBJECTIVES A systematic review with meta-analysis was conducted to synthesise evidence on the efficacy of dietary supplements containing isolated organic compounds for weight loss. SUBJECTS/METHODS Four electronic databases (Medline, Embase, Web of Science, Cinahl) were searched until December 2019. Sixty-seven randomised placebo-controlled trials of dietary supplements containing isolated organic compounds for weight loss were included. Meta-analyses were conducted for chitosan, glucomannan, conjugated linoleic acid and fructans, comparing mean weight difference post-intervention between participants receiving the dietary supplement or placebo. RESULTS Statistically significant weight differences compared to placebo were observed for chitosan (-1.84 kg; 95% confidence interval [CI] -2.79, -0.88; p < 0.01), glucomannan (-1.27 kg; 95%CI -2.45, -0.09; p = 0.04), and conjugated linoleic acid (-1.08 kg; 95%CI -1.61, -0.55; p < 0.01). None met our threshold for clinical significance (≥2.5 kg). There was no statistically significant effect on weight for fructans compared to placebo (p = 0.24). For dietary supplements with an inadequate number of trials for meta-analysis, a statistically and borderline clinically significant weight difference compared to placebo was found for modified cellulose, manno-oligosaccharides (in males), blood orange juice extract, and three multiple-ingredient dietary supplements. These were only reported in one trial of each. Thus, more evidence is needed before recommending them for weight loss. CONCLUSIONS While some dietary supplements containing isolated organic compounds warrant further investigation to determine efficacy and safety, there is currently insufficient evidence to recommend any of these dietary supplements for weight loss.
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Affiliation(s)
- Erica Bessell
- The University of Sydney, The Boden Collaboration for Obesity, Nutrition, Exercise & Eating Disorders, Charles Perkins Centre, Faculty of Medicine and Health, Sydney, NSW, Australia.
| | - Alison Maunder
- The University of Sydney, The Boden Collaboration for Obesity, Nutrition, Exercise & Eating Disorders, Charles Perkins Centre, Faculty of Medicine and Health, Sydney, NSW, Australia.,Western Sydney University, NICM Health Research Institute, Penrith, NSW, Australia
| | - Romy Lauche
- Southern Cross University, National Centre for Naturopathic Medicine, Lismore, NSW, Australia.,University of Technology Sydney, Australian Research Centre in Complementary and Integrative Medicine (ARCCIM), School of Public Health, Faculty of Health, Sydney, NSW, Australia
| | - Jon Adams
- University of Technology Sydney, Australian Research Centre in Complementary and Integrative Medicine (ARCCIM), School of Public Health, Faculty of Health, Sydney, NSW, Australia
| | - Amanda Sainsbury
- The University of Western Australia, School of Human Sciences, Faculty of Science, Perth, WA, Australia
| | - Nicholas R Fuller
- The University of Sydney, The Boden Collaboration for Obesity, Nutrition, Exercise & Eating Disorders, Charles Perkins Centre, Faculty of Medicine and Health, Sydney, NSW, Australia
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10
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Batsis JA, Apolzan JW, Bagley PJ, Blunt HB, Divan V, Gill S, Golden A, Gundamraj S, Heymsfield S, Kahan S, Kopatsis K, Port A, Parks EP, Reilly CA, Rubino D, Saunders KH, Shean R, Tabaza L, Stanley A, Tchang BG, Gundumraj S, Kidambi S. A Systematic Review of Dietary Supplements and Alternative Therapies for Weight Loss. Obesity (Silver Spring) 2021; 29:1102-1113. [PMID: 34159755 PMCID: PMC8231729 DOI: 10.1002/oby.23110] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/06/2020] [Accepted: 12/08/2020] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Dietary supplements and alternative therapies are commercialized as a panacea for obesity/weight gain as a result of the minimal regulatory requirements in demonstrating efficacy. These products may indirectly undermine the value of guideline-driven obesity treatments. Included in this study is a systematic review of the literature of purported dietary supplements and alternative therapies for weight loss. METHODS A systematic review was conducted to evaluate the efficacy of dietary supplements and alternative therapies for weight loss in participants aged ≥18 years. Searches of Medline (PubMed), Cochrane Library, Web of Science, CINAHL, and Embase (Ovid) were conducted. Risk of bias and results were summarized qualitatively. RESULTS Of the 20,504 citations retrieved in the database search, 1,743 full-text articles were reviewed, 315 of which were randomized controlled trials evaluating the efficacy of 14 purported dietary supplements, therapies, or a combination thereof. Risk of bias and sufficiency of data varied widely. Few studies (n = 52 [16.5%]) were classified as low risk and sufficient to support efficacy. Of these, only 16 (31%) noted significant pre/post intergroup differences in weight (range: 0.3-4.93 kg). CONCLUSIONS Dietary supplements and alternative therapies for weight loss have a limited high-quality evidence base of efficacy. Practitioners and patients should be aware of the scientific evidence of claims before recommending use.
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Affiliation(s)
- John A. Batsis
- Division of Geriatric Medicine, School of Medicine, and the Department of Nutrition, The Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - John W. Apolzan
- Pennington Biomedical Research Center, Louisiana State University Sysytem, Baton Rouge, Louisiana
| | | | | | | | - Sonia Gill
- University of California, Davis School of Medicine, Sacramento, California
| | | | | | - Steven Heymsfield
- Pennington Biomedical Research Center, Louisiana State University Sysytem, Baton Rouge, Louisiana
| | - Scott Kahan
- Director, National Center for Weight and Wellness, George Washington University Milken Institute School of Public Health, Washington, DC
| | | | - Ava Port
- Division of Endocrinology, Diabetes and Nutrition, University of Maryland School of Medicine, Baltimore, MD
| | - Elizabeth Prout Parks
- The Children’s Hospital of Philadelphia, Division of Gastroenterology, Hepatology and Nutrition, The Healthy Weight Program, Perelman Medical Center, University of Pennsylvania
| | - Clifford A. Reilly
- The Robert Larner, M.D. College of Medicine at The University of Vermont, Burlington VT
| | - Domenica Rubino
- Washington Center for Weight Management and Research, Arlington, VA
| | - Katherine H. Saunders
- Comprehensive Weight Control Center, Division of Endocrinology, Diabetes, and Metabolism, Weill Cornell Medicine, New York, NY
| | - Ryan Shean
- Dartmouth College, Hanover, New Hampshire
| | - Luai Tabaza
- Albert Einstein Medical Center, Philadelphia, PA
| | - Abishek Stanley
- Pennington Biomedical Research Center, Louisiana State University Sysytem, Baton Rouge, Louisiana
| | - Beverly G. Tchang
- Comprehensive Weight Control Center, Division of Endocrinology, Diabetes, and Metabolism, Weill Cornell Medicine, New York, NY
| | - Shivani Gundumraj
- AT Still University School of Osteopathic Medicine in Arizona, Mesa, AZ
| | - Srividya Kidambi
- Division of Endocrinology and Molecular Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
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11
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Monnard CR, Dulloo AG. Polyunsaturated fatty acids as modulators of fat mass and lean mass in human body composition regulation and cardiometabolic health. Obes Rev 2021; 22 Suppl 2:e13197. [PMID: 33471425 DOI: 10.1111/obr.13197] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/22/2022]
Abstract
It is now recognized that the amount and type of dietary fat consumed play an important role in metabolic health. In humans, high intake of polyunsaturated fatty acids (PUFAs) has been associated with reductions in cardiovascular disease risk, improvements in glucose homeostasis, and changes in body composition that involve reductions in central adiposity and, more recently, increases in lean body mass. There is also emerging evidence, which suggests that high intakes of the plant-based essential fatty acids (ePUFAs)-n-6 linoleic acid (LA) and n-3 α-linolenic acid (ALA)-have a greater impact on body composition (fat mass and lean mass) and on glucose homeostasis than the marine-derived long-chain n-3 PUFA-eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In addition, high intake of both ePUFAs (LA and ALA) may also have anti-inflammatory effects in humans. The purpose of this review is to highlight the emerging evidence, from both epidemiological prospective studies and clinical intervention trials, of a role for PUFA, in particular ePUFA, in the long-term regulation of body weight and body composition, and their impact on cardiometabolic health. It also discusses current notions about the mechanisms by which PUFAs modulate fat mass and lean mass through altered control of energy intake, thermogenesis, or lean-fat partitioning.
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Affiliation(s)
- Cathriona R Monnard
- Faculty of Science and Medicine, Department of Endocrinology, Metabolism and Cardiovascular System, University of Fribourg, Fribourg, Switzerland
| | - Abdul G Dulloo
- Faculty of Science and Medicine, Department of Endocrinology, Metabolism and Cardiovascular System, University of Fribourg, Fribourg, Switzerland
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12
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A Three-Month Consumption of Eggs Enriched with ω-3, ω-5 and ω-7 Polyunsaturated Fatty Acids Significantly Decreases the Waist Circumference of Subjects at Risk of Developing Metabolic Syndrome: A Double-Blind Randomized Controlled Trial. Nutrients 2021; 13:nu13020663. [PMID: 33670720 PMCID: PMC7923083 DOI: 10.3390/nu13020663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/10/2021] [Accepted: 02/16/2021] [Indexed: 02/01/2023] Open
Abstract
Alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), rumenic acid (RmA), and punicic acid (PunA) are claimed to influence several physiological functions including insulin sensitivity, lipid metabolism and inflammatory processes. In this double-blind randomized controlled trial, we investigated the combined effect of ALA, DHA, RmA and PunA on subjects at risk of developing metabolic syndrome. Twenty-four women and men were randomly assigned to two groups. Each day, they consumed two eggs enriched with oleic acid (control group) or enriched with ALA, DHA, RmA, and PunA (test group) for 3 months. The waist circumference decreased significantly (−3.17 cm; p < 0.001) in the test group. There were no major changes in plasma insulin and blood glucose in the two groups. The dietary treatments had no significant effect on endothelial function as measured by peripheral arterial tonometry, although erythrocyte nitrosylated hemoglobin concentrations tended to decrease. The high consumption of eggs induced significant elevations in plasma low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol (p < 0.001), which did not result in any change in the LDL/HDL ratio in both groups. These results indicate that consumption of eggs enriched with ALA, DHA, RmA and PunA resulted in favorable changes in abdominal obesity without affecting other factors of the metabolic syndrome.
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13
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Herrema H, Niess JH. Intestinal microbial metabolites in human metabolism and type 2 diabetes. Diabetologia 2020; 63:2533-2547. [PMID: 32880688 PMCID: PMC7641949 DOI: 10.1007/s00125-020-05268-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/13/2020] [Indexed: 12/12/2022]
Abstract
Humans with the metabolic syndrome and type 2 diabetes have an altered gut microbiome. Emerging evidence indicates that it is not only the microorganisms and their structural components, but also their metabolites that influences the host and contributes to the development of the metabolic syndrome and type 2 diabetes. Here, we discuss some of the mechanisms underlying how microbial metabolites are recognised by the host or are further processed endogenously in the context of type 2 diabetes. We discuss the possibility that gut-derived microbial metabolites fuel the development of the metabolic syndrome and type 2 diabetes. Graphical abstract.
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Affiliation(s)
- Hilde Herrema
- Department of Experimental Vascular Medicine, Amsterdam University Medical Centers, Location AMC, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands.
| | - Jan Hendrik Niess
- Department of Biomedicine, University of Basel, Hebelstrasse 20, CH-4031, Basel, Switzerland.
- University Center for Gastrointestinal and Liver Diseases, St Clara Hospital and University Hospital of Basel, Basel, Switzerland.
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14
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Wang J, Han L, Wang D, Li P, Shahidi F. Conjugated Fatty Acids in Muscle Food Products and Their Potential Health Benefits: A Review. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:13530-13540. [PMID: 33175544 DOI: 10.1021/acs.jafc.0c05759] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Conjugated fatty acids (CFAs) are a group of positional and geometric isomers of polyunsaturated fatty acids (PUFAs) with conjugated double bonds. There are several subgroups of CFAs including conjugated linoleic acids (CLAs), conjugated linolenic acids (CLNAs), conjugated eicosapentaenoic acids (CEPAs), and conjugated docosahexaenoic acids (CDHAs). CFAs, especially CLAs, have been studied in recent years both for their health benefits and factors that affect their level in muscle food products. CFAs have been reported in numerous studies as having antitumor, antiobesity, antidiabetes, anticardiovascular disease, and modulating immune system effects. These biological activies are involved in changes of lipid peroxidation and energy expenditure, as well as inhibitory effects on the hormone receptor, lipid metabolism, lipoprotein lipase activity, and adiponectin production. A large body of studies has revealed that the diet, processing, storage conditions, slaughter season, and age are common factors that affect CFA content in muscle food products, as detailed in this review. Recommendations are made regarding animal farming and meat product processing to obtain high CFA content meat products and to optimize the benefits of CFA for health promotion.
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Affiliation(s)
- Jiankang Wang
- School of Food and Biological Engineering, and Natural Food Macromolecule Research Center, Shaanxi University of Science and Technology, Xi'an 710021, P. R. China
| | - Linxiao Han
- School of Food and Biological Engineering, and Natural Food Macromolecule Research Center, Shaanxi University of Science and Technology, Xi'an 710021, P. R. China
| | - Daoying Wang
- Institute of Agricultural Products Processing, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, P. R. China
| | - Pengpeng Li
- Institute of Agricultural Products Processing, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, P. R. China
| | - Fereidoon Shahidi
- Departments of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada
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15
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Rodriguez J, Olivares M, Delzenne NM. Implication of the Gut Microbiota in Metabolic Inflammation Associated with Nutritional Disorders and Obesity. Mol Nutr Food Res 2020; 65:e1900481. [PMID: 33111450 DOI: 10.1002/mnfr.201900481] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 09/22/2020] [Indexed: 12/12/2022]
Abstract
SCOPE More than a decade ago, the concept of "metabolic endotoxemia" is elaborated on the fact that some bacterial components, classified as microbial associated membrane pathogens (MAMPs) can pass through the gut barrier and create a systemic low tone inflammation. METHODS AND RESULTS The translocation of lipopolysaccharides and its contribution to systemic inflammation are largely studied in murine models of obesity, allowing to unravel the molecular pathways involved in the process. Many different pathological contexts evoke the loss of gut barrier as an event contributing to inflammation and thereby driving metabolic and behavioral alterations. CONCLUSION This review describes the role of nutrition as a modulator of metabolic regulation and focuses on the contribution of the gut microbiota in the process of the production of a large diversity of bioactive metabolites. The two first sections of the review will be dedicated to the impact of nutritional disorders on both the gut microbiota composition and on metabolic inflammation. The last and more prominent section will describe the role of different nutrient-derived gut metabolites on the gut barrier integrity, metabolic inflammation, and peripheral tissue alterations during obesity or associated complications.
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Affiliation(s)
- Julie Rodriguez
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, UCLouvain, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Marta Olivares
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, UCLouvain, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Nathalie M Delzenne
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, UCLouvain, Université catholique de Louvain, Brussels, 1200, Belgium
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16
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Hooper L, Martin N, Jimoh OF, Kirk C, Foster E, Abdelhamid AS. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database Syst Rev 2020; 8:CD011737. [PMID: 32827219 PMCID: PMC8092457 DOI: 10.1002/14651858.cd011737.pub3] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally, it is unclear whether the energy from saturated fats eliminated from the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein. OBJECTIVES To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO), polyunsaturated (PUFA), monounsaturated fat (MUFA) and/or protein on mortality and cardiovascular morbidity, using all available randomised clinical trials. SEARCH METHODS We updated our searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) on 15 October 2019, and searched Clinicaltrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) on 17 October 2019. SELECTION CRITERIA Included trials fulfilled the following criteria: 1) randomised; 2) intention to reduce saturated fat intake OR intention to alter dietary fats and achieving a reduction in saturated fat; 3) compared with higher saturated fat intake or usual diet; 4) not multifactorial; 5) in adult humans with or without cardiovascular disease (but not acutely ill, pregnant or breastfeeding); 6) intervention duration at least 24 months; 7) mortality or cardiovascular morbidity data available. DATA COLLECTION AND ANALYSIS Two review authors independently assessed inclusion, extracted study data and assessed risk of bias. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity analyses, funnel plots and GRADE assessment. MAIN RESULTS We included 15 randomised controlled trials (RCTs) (16 comparisons, 56,675 participants), that used a variety of interventions from providing all food to advice on reducing saturated fat. The included long-term trials suggested that reducing dietary saturated fat reduced the risk of combined cardiovascular events by 17% (risk ratio (RR) 0.83; 95% confidence interval (CI) 0.70 to 0.98, 12 trials, 53,758 participants of whom 8% had a cardiovascular event, I² = 67%, GRADE moderate-quality evidence). Meta-regression suggested that greater reductions in saturated fat (reflected in greater reductions in serum cholesterol) resulted in greater reductions in risk of CVD events, explaining most heterogeneity between trials. The number needed to treat for an additional beneficial outcome (NNTB) was 56 in primary prevention trials, so 56 people need to reduce their saturated fat intake for ~four years for one person to avoid experiencing a CVD event. In secondary prevention trials, the NNTB was 53. Subgrouping did not suggest significant differences between replacement of saturated fat calories with polyunsaturated fat or carbohydrate, and data on replacement with monounsaturated fat and protein was very limited. We found little or no effect of reducing saturated fat on all-cause mortality (RR 0.96; 95% CI 0.90 to 1.03; 11 trials, 55,858 participants) or cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 10 trials, 53,421 participants), both with GRADE moderate-quality evidence. There was little or no effect of reducing saturated fats on non-fatal myocardial infarction (RR 0.97, 95% CI 0.87 to 1.07) or CHD mortality (RR 0.97, 95% CI 0.82 to 1.16, both low-quality evidence), but effects on total (fatal or non-fatal) myocardial infarction, stroke and CHD events (fatal or non-fatal) were all unclear as the evidence was of very low quality. There was little or no effect on cancer mortality, cancer diagnoses, diabetes diagnosis, HDL cholesterol, serum triglycerides or blood pressure, and small reductions in weight, serum total cholesterol, LDL cholesterol and BMI. There was no evidence of harmful effects of reducing saturated fat intakes. AUTHORS' CONCLUSIONS The findings of this updated review suggest that reducing saturated fat intake for at least two years causes a potentially important reduction in combined cardiovascular events. Replacing the energy from saturated fat with polyunsaturated fat or carbohydrate appear to be useful strategies, while effects of replacement with monounsaturated fat are unclear. The reduction in combined cardiovascular events resulting from reducing saturated fat did not alter by study duration, sex or baseline level of cardiovascular risk, but greater reduction in saturated fat caused greater reductions in cardiovascular events.
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Affiliation(s)
- Lee Hooper
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Nicole Martin
- Institute of Health Informatics Research, University College London, London, UK
| | - Oluseyi F Jimoh
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Christian Kirk
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Eve Foster
- Norwich Medical School, University of East Anglia, Norwich, UK
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17
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Mądry E, Malesza IJ, Subramaniapillai M, Czochralska-Duszyńska A, Walkowiak M, Miśkiewicz-Chotnicka A, Walkowiak J, Lisowska A. Body Fat Changes and Liver Safety in Obese and Overweight Women Supplemented with Conjugated Linoleic Acid: A 12-Week Randomised, Double-Blind, Placebo-Controlled Trial. Nutrients 2020; 12:nu12061811. [PMID: 32560516 PMCID: PMC7353155 DOI: 10.3390/nu12061811] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/03/2020] [Accepted: 06/16/2020] [Indexed: 12/25/2022] Open
Abstract
Preliminary evidence suggests that conjugated linoleic acid (CLA) may reduce body weight and affect body composition. The present study assessed the effect of CLA supplementation on body fat composition in overweight and obese women, while also evaluating the liver safety of CLA use. Seventy-four obese or overweight women were randomly assigned to receive 3 g/day CLA or placebo for 12 weeks. Body composition (dual-energy X-ray absorptiometry) and liver function (13C-methacetin breath test and serum liver enzymes) were assessed before and after the trial. Patients receiving CLA experienced a significant reduction of total body fat expressed as mass (p = 0.0007) and percentage (p = 0.0006), android adipose tissue (p = 0.0002), gynoid adipose tissue (p = 0.0028), and visceral adipose tissue (p = 4.2 × 10−9) as well as a significant increase in lean body mass to height (p = 6.1 × 10−11) when compared to those receiving a placebo. The maximum momentary 13C recovery changes and end-point values were significantly higher in the CLA group when compared to the placebo group (p = 0.0385 and p = 0.0076, respectively). There were no significant changes in alanine aminotransferase, asparagine aminotransferase, and gamma-glutamyl transpeptidase activities between the groups. In conclusion, CLA supplementation was well tolerated and safe for the liver, which shows beneficial effects on fat composition in overweight and obese women.
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Affiliation(s)
- Edyta Mądry
- Department of Physiology, Poznan University of Medical Sciences, 61701 Poznań, Poland; (M.S.); (A.C.-D.)
- Correspondence: ; Tel.: +48-501-728-956
| | - Ida Judyta Malesza
- Department of Pediatric Gastroenterology and Metabolic Diseases, Poznan University of Medical Sciences, 61701 Poznań, Poland; (I.J.M.); (A.M.-C.); (J.W.)
| | - Mehala Subramaniapillai
- Department of Physiology, Poznan University of Medical Sciences, 61701 Poznań, Poland; (M.S.); (A.C.-D.)
| | | | - Marek Walkowiak
- Division of Reproduction, Department of Gynecology and Obstetrics, Poznan University of Medical Sciences, 61701 Poznań, Poland;
| | - Anna Miśkiewicz-Chotnicka
- Department of Pediatric Gastroenterology and Metabolic Diseases, Poznan University of Medical Sciences, 61701 Poznań, Poland; (I.J.M.); (A.M.-C.); (J.W.)
| | - Jarosław Walkowiak
- Department of Pediatric Gastroenterology and Metabolic Diseases, Poznan University of Medical Sciences, 61701 Poznań, Poland; (I.J.M.); (A.M.-C.); (J.W.)
| | - Aleksandra Lisowska
- Department of Clinical Auxology and Pediatric Nursing, Poznan University of Medical Sciences, 61701 Poznań, Poland;
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18
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Hooper L, Abdelhamid AS, Jimoh OF, Bunn D, Skeaff CM. Effects of total fat intake on body fatness in adults. Cochrane Database Syst Rev 2020; 6:CD013636. [PMID: 32476140 PMCID: PMC7262429 DOI: 10.1002/14651858.cd013636] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The ideal proportion of energy from fat in our food and its relation to body weight is not clear. In order to prevent overweight and obesity in the general population, we need to understand the relationship between the proportion of energy from fat and resulting weight and body fatness in the general population. OBJECTIVES To assess the effects of proportion of energy intake from fat on measures of body fatness (including body weight, waist circumference, percentage body fat and body mass index) in people not aiming to lose weight, using all appropriate randomised controlled trials (RCTs) of at least six months duration. SEARCH METHODS We searched CENTRAL, MEDLINE, Embase, Clinicaltrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) to October 2019. We did not limit the search by language. SELECTION CRITERIA Trials fulfilled the following criteria: 1) randomised intervention trial, 2) included adults aged at least 18 years, 3) randomised to a lower fat versus higher fat diet, without the intention to reduce weight in any participants, 4) not multifactorial and 5) assessed a measure of weight or body fatness after at least six months. We duplicated inclusion decisions and resolved disagreement by discussion or referral to a third party. DATA COLLECTION AND ANALYSIS We extracted data on the population, intervention, control and outcome measures in duplicate. We extracted measures of body fatness (body weight, BMI, percentage body fat and waist circumference) independently in duplicate at all available time points. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity, funnel plot analyses and GRADE assessment. MAIN RESULTS We included 37 RCTs (57,079 participants). There is consistent high-quality evidence from RCTs that reducing total fat intake results in small reductions in body fatness; this was seen in almost all included studies and was highly resistant to sensitivity analyses (GRADE high-consistency evidence, not downgraded). The effect of eating less fat (compared with higher fat intake) is a mean body weight reduction of 1.4 kg (95% confidence interval (CI) -1.7 to -1.1 kg, in 53,875 participants from 26 RCTs, I2 = 75%). The heterogeneity was explained in subgrouping and meta-regression. These suggested that greater weight loss results from greater fat reductions in people with lower fat intake at baseline, and people with higher body mass index (BMI) at baseline. The size of the effect on weight does not alter over time and is mirrored by reductions in BMI (MD -0.5 kg/m2, 95% CI -0.6 to -0.3, 46,539 participants in 14 trials, I2 = 21%), waist circumference (MD -0.5 cm, 95% CI -0.7 to -0.2, 16,620 participants in 3 trials; I2 = 21%), and percentage body fat (MD -0.3% body fat, 95% CI -0.6 to 0.00, P = 0.05, in 2350 participants in 2 trials; I2 = 0%). There was no suggestion of harms associated with low fat diets that might mitigate any benefits on body fatness. The reduction in body weight was reflected in small reductions in LDL (-0.13 mmol/L, 95% CI -0.21 to -0.05), and total cholesterol (-0.23 mmol/L, 95% CI -0.32 to -0.14), with little or no effect on HDL cholesterol (-0.02 mmol/L, 95% CI -0.03 to 0.00), triglycerides (0.01 mmol/L, 95% CI -0.05 to 0.07), systolic (-0.75 mmHg, 95% CI -1.42 to -0.07) or diastolic blood pressure(-0.52 mmHg, 95% CI -0.95 to -0.09), all GRADE high-consistency evidence or quality of life (0.04, 95% CI 0.01 to 0.07, on a scale of 0 to 10, GRADE low-consistency evidence). AUTHORS' CONCLUSIONS Trials where participants were randomised to a lower fat intake versus a higher fat intake, but with no intention to reduce weight, showed a consistent, stable but small effect of low fat intake on body fatness: slightly lower weight, BMI, waist circumference and percentage body fat compared with higher fat arms. Greater fat reduction, lower baseline fat intake and higher baseline BMI were all associated with greater reductions in weight. There was no evidence of harm to serum lipids, blood pressure or quality of life, but rather of small benefits or no effect.
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Affiliation(s)
- Lee Hooper
- Norwich Medical School, University of East Anglia, Norwich, UK
| | | | - Oluseyi F Jimoh
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Diane Bunn
- Norwich Medical School, University of East Anglia, Norwich, UK
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19
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Hooper L, Martin N, Jimoh OF, Kirk C, Foster E, Abdelhamid AS. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database Syst Rev 2020; 5:CD011737. [PMID: 32428300 PMCID: PMC7388853 DOI: 10.1002/14651858.cd011737.pub2] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally, it is unclear whether the energy from saturated fats eliminated from the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein. OBJECTIVES To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO), polyunsaturated (PUFA), monounsaturated fat (MUFA) and/or protein on mortality and cardiovascular morbidity, using all available randomised clinical trials. SEARCH METHODS We updated our searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) on 15 October 2019, and searched Clinicaltrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) on 17 October 2019. SELECTION CRITERIA Included trials fulfilled the following criteria: 1) randomised; 2) intention to reduce saturated fat intake OR intention to alter dietary fats and achieving a reduction in saturated fat; 3) compared with higher saturated fat intake or usual diet; 4) not multifactorial; 5) in adult humans with or without cardiovascular disease (but not acutely ill, pregnant or breastfeeding); 6) intervention duration at least 24 months; 7) mortality or cardiovascular morbidity data available. DATA COLLECTION AND ANALYSIS Two review authors independently assessed inclusion, extracted study data and assessed risk of bias. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity analyses, funnel plots and GRADE assessment. MAIN RESULTS We included 15 randomised controlled trials (RCTs) (16 comparisons, ~59,000 participants), that used a variety of interventions from providing all food to advice on reducing saturated fat. The included long-term trials suggested that reducing dietary saturated fat reduced the risk of combined cardiovascular events by 21% (risk ratio (RR) 0.79; 95% confidence interval (CI) 0.66 to 0.93, 11 trials, 53,300 participants of whom 8% had a cardiovascular event, I² = 65%, GRADE moderate-quality evidence). Meta-regression suggested that greater reductions in saturated fat (reflected in greater reductions in serum cholesterol) resulted in greater reductions in risk of CVD events, explaining most heterogeneity between trials. The number needed to treat for an additional beneficial outcome (NNTB) was 56 in primary prevention trials, so 56 people need to reduce their saturated fat intake for ~four years for one person to avoid experiencing a CVD event. In secondary prevention trials, the NNTB was 32. Subgrouping did not suggest significant differences between replacement of saturated fat calories with polyunsaturated fat or carbohydrate, and data on replacement with monounsaturated fat and protein was very limited. We found little or no effect of reducing saturated fat on all-cause mortality (RR 0.96; 95% CI 0.90 to 1.03; 11 trials, 55,858 participants) or cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 10 trials, 53,421 participants), both with GRADE moderate-quality evidence. There was little or no effect of reducing saturated fats on non-fatal myocardial infarction (RR 0.97, 95% CI 0.87 to 1.07) or CHD mortality (RR 0.97, 95% CI 0.82 to 1.16, both low-quality evidence), but effects on total (fatal or non-fatal) myocardial infarction, stroke and CHD events (fatal or non-fatal) were all unclear as the evidence was of very low quality. There was little or no effect on cancer mortality, cancer diagnoses, diabetes diagnosis, HDL cholesterol, serum triglycerides or blood pressure, and small reductions in weight, serum total cholesterol, LDL cholesterol and BMI. There was no evidence of harmful effects of reducing saturated fat intakes. AUTHORS' CONCLUSIONS The findings of this updated review suggest that reducing saturated fat intake for at least two years causes a potentially important reduction in combined cardiovascular events. Replacing the energy from saturated fat with polyunsaturated fat or carbohydrate appear to be useful strategies, while effects of replacement with monounsaturated fat are unclear. The reduction in combined cardiovascular events resulting from reducing saturated fat did not alter by study duration, sex or baseline level of cardiovascular risk, but greater reduction in saturated fat caused greater reductions in cardiovascular events.
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Affiliation(s)
- Lee Hooper
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Nicole Martin
- Institute of Health Informatics Research, University College London, London, UK
| | - Oluseyi F Jimoh
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Christian Kirk
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Eve Foster
- Norwich Medical School, University of East Anglia, Norwich, UK
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20
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Oteng AB, Kersten S. Mechanisms of Action of trans Fatty Acids. Adv Nutr 2020; 11:697-708. [PMID: 31782488 PMCID: PMC7231579 DOI: 10.1093/advances/nmz125] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/03/2019] [Accepted: 10/31/2019] [Indexed: 12/11/2022] Open
Abstract
Human studies have established a positive association between the intake of industrial trans fatty acids and the development of cardiovascular diseases, leading several countries to enact laws that restrict the presence of industrial trans fatty acids in food products. However, trans fatty acids cannot be completely eliminated from the human diet since they are also naturally present in meat and dairy products of ruminant animals. Moreover, bans on industrial trans fatty acids have not yet been instituted in all countries. The epidemiological evidence against trans fatty acids by far overshadows mechanistic insights that may explain how trans fatty acids achieve their damaging effects. This review focuses on the mechanisms that underlie the deleterious effects of trans fatty acids by juxtaposing effects of trans fatty acids against those of cis-unsaturated fatty acids and saturated fatty acids (SFAs). This review also carefully explores the argument that ruminant trans fatty acids have differential effects from industrial trans fatty acids. Overall, in vivo and in vitro studies demonstrate that industrial trans fatty acids promote inflammation and endoplasmic reticulum (ER) stress, although to a lesser degree than SFAs, whereas cis-unsaturated fatty acids are protective against ER stress and inflammation. Additionally, industrial trans fatty acids promote fat storage in the liver at the expense of adipose tissue compared with cis-unsaturated fatty acids and SFAs. In cultured hepatocytes and adipocytes, industrial trans fatty acids, but not cis-unsaturated fatty acids or SFAs, stimulate the cholesterol synthesis pathway by activating sterol regulatory element binding protein (SREBP) 2-mediated gene regulation. Interestingly, although industrial and ruminant trans fatty acids show similar effects on human plasma lipoproteins, in preclinical models, only industrial trans fatty acids promote inflammation, ER stress, and cholesterol synthesis. Overall, clearer insight into the molecular mechanisms of action of trans fatty acids may create new therapeutic windows for the treatment of diseases characterized by disrupted lipid metabolism.
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Affiliation(s)
- Antwi-Boasiako Oteng
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| | - Sander Kersten
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
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21
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Maher T, Deleuse M, Thondre S, Shafat A, Clegg ME. A comparison of the satiating properties of medium-chain triglycerides and conjugated linoleic acid in participants with healthy weight and overweight or obesity. Eur J Nutr 2020; 60:203-215. [PMID: 32248292 PMCID: PMC7867511 DOI: 10.1007/s00394-020-02235-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 03/25/2020] [Indexed: 12/24/2022]
Abstract
Purpose Inconsistent evidence exists for greater satiety after medium-chain triglycerides (MCT) or conjugated linoleic acid (CLA) compared to long-chain triglycerides (LCT). Furthermore, the mechanisms are poorly understood and effects in people with a healthy weight and those with overweight/obesity have not been compared. This study aimed to compare appetite responses in these groups and examine the mechanisms behind any differences. Methods Fifteen participants with healthy weight (BMI: 22.7 ± 1.9 kg·m−2) and fourteen participants with overweight/obesity (BMI: 30.9 ± 3.9 kg·m−2) consumed a breakfast containing either 23.06 g vegetable oil (CON), 25.00 g MCT oil (MCT), or 6.25 g CLA and 16.80 g vegetable oil (CLA). Appetite, peptide YY (PYY), total ghrelin (TG), β-hydroxybutyrate, and gastric emptying (GE) were measured throughout. Energy intake was assessed at an ad libitum lunch and throughout the following ~ 36 h. Results Neither MCT nor CLA decreased ad libitum intake; however MCT decreased day 1 energy intake (P = 0.031) and the 48-h period (P = 0.005) compared to CON. MCT delayed GE (P ≤ 0.01) compared to CON, whereas CLA did not. PYY and TG concentrations were not different (P = 0.743 and P = 0.188, respectively), but MCT increased β-hydroxybutyrate concentrations compared to CON (P = 0.005) and CLA (P < 0.001). β-hydroxybutyrate concentrations were higher in participants with overweight/obesity (P = 0.009). Conclusion Consumption of MCT reduces energy intake in the subsequent 48 h, whereas CLA does not. Delayed gastric emptying or increased β-hydroxybutyrate concentrations may mediate this.
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Affiliation(s)
- Tyler Maher
- Diet and Cardiometabolic Health Research Group, Department of Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London, London, SE1 9NH, UK.,Faculty of Health and Life Sciences, Oxford Brookes Centre for Nutrition and Health, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK
| | - Martina Deleuse
- Faculty of Health and Life Sciences, Oxford Brookes Centre for Nutrition and Health, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK
| | - Sangeetha Thondre
- Faculty of Health and Life Sciences, Oxford Brookes Centre for Nutrition and Health, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK
| | - Amir Shafat
- Physiology, School of Medicine, National University of Ireland, Galway, H91 W5P7, Ireland
| | - Miriam E Clegg
- Faculty of Health and Life Sciences, Oxford Brookes Centre for Nutrition and Health, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK. .,Department of Food and Nutritional Sciences, University of Reading, Harry Nursten Building, Whiteknights, Reading, RG6 6AP, UK.
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22
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From Association to Causality: the Role of the Gut Microbiota and Its Functional Products on Host Metabolism. Mol Cell 2020; 78:584-596. [PMID: 32234490 DOI: 10.1016/j.molcel.2020.03.005] [Citation(s) in RCA: 156] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/30/2020] [Accepted: 03/02/2020] [Indexed: 12/12/2022]
Abstract
Many genomic studies have revealed associations between the gut microbiota composition and host metabolism. These observations led to the idea that a causal relationship could exist between the microbiota and metabolic diseases, a concept supported by studies showing compositional changes in the microbial community in metabolic diseases and transmissibility of host phenotype via microbiota transfer. Accumulating data suggest that the microbiota may affect host metabolic phenotypes through the production of metabolites. These bioactive microbial metabolites, sensitive fingerprints of microbial function, can act as inter-kingdom signaling messengers via penetration into host blood circulation and tissues. These fingerprints may be used for diagnostic purposes, and increased understanding of strain specificity in producing microbial metabolites can identify bacterial strains or specific metabolites that can be used for therapeutic purposes. Here, we will review data supporting the causal role of the gut microbiota in metabolism and discuss mechanisms and potential clinical implications.
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23
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Abdelatty AM, Badr OAM, Mohamed SA, Khattab MS, Dessouki SHM, Farid OAA, Elolimy AA, Sakr OG, Elhady MA, Mehesen G, Bionaz M. Long term conjugated linoleic acid supplementation modestly improved growth performance but induced testicular tissue apoptosis and reduced sperm quality in male rabbit. PLoS One 2020; 15:e0226070. [PMID: 31923252 PMCID: PMC6953797 DOI: 10.1371/journal.pone.0226070] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 11/19/2019] [Indexed: 12/20/2022] Open
Abstract
Conjugated linoleic acid (CLA) is known for its multiple benefits including improvement of growth, increasing lean mass, and anti-carcinogenic effects. However, when used in long-term supplementations CLA does not improve semen parameters in boar and bull and reduces fertility in Japanese quails. The content of unsaturated fatty acids in dietary lipids plays a significant role in spermatogenesis owning the high proportion of unsaturated fatty acids in plasma membrane of sperms. Whether CLA plays a role in testicular tissue and epididymal fat is still unknown. Therefore, in this study we hypothesize that long-term supplementation of equal proportion of CLA isomer mix (c9,t11-CLA and t10,c12- CLA) in rabbit bucks might alter male reproductive potentials. Twelve V-Line weaned male rabbits were used in 26 weeks trial, rabbits were individually raised and randomly allocated into three dietary groups. Control group (CON) received a basal diet, a group received 0.5% CLA (CLA 0.5%), and a group received 1% CLA (CLA 1%). Rabbits were euthanized at the end of the trial and several parameters were evaluated related to growth, semen quality, and testicular and epididymal tissue histopathology and transcriptome. The long-term supplementation of CLA increased feed intake by 5% and body weight by 2-3%. CLA 1% decreased sperm progressive motility. In testicular tissue L-carnitine and α-tocopherol were decreased by CLA supplementation. In epididymal fat, CLA tended to decrease concentration of polyunsaturated fatty acids, the expression of SCD5 gene was upregulated by CLA 1% and CASP3 gene was upregulated by CLA 0.5%. Transcription of PPARG was downregulated by CLA. Feeding 1% CLA also decreased testicular epithelial thickness. Long-term supplementation of CLA modestly enhanced male rabbit growth, but negatively impacted male reproduction, especially at high dose of CLA.
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Affiliation(s)
- A. M. Abdelatty
- Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - O. A. M. Badr
- Department of Genetics and Genetic Engineering, Faculty of Agriculture, Benha University, Qalyubia, Egypt
| | - S. A. Mohamed
- Department of Genetics and Genetic Engineering, Faculty of Agriculture, Benha University, Qalyubia, Egypt
| | - M. S. Khattab
- Department of Pathology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - SH. M. Dessouki
- Department of Animal Production, Faculty of Agriculture, Cairo University, Giza, Egypt
| | - O. A. A. Farid
- Department of Physiology, National Organization for Drug Control and Research, Giza, Egypt
| | - A. A. Elolimy
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
- Arkansas Children’s Nutrition Center, Little Rock, AR, United States of America
- Department of Animal Production, National Research Centre, Giza, Egypt
| | - O. G. Sakr
- Department of Animal Production, Faculty of Agriculture, Cairo University, Giza, Egypt
| | - M. A. Elhady
- Department of Toxicology and Forensic Medicine, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - G. Mehesen
- Department of Animal Production, Faculty of Agriculture, Cairo University, Giza, Egypt
| | - M. Bionaz
- Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, OR, United States of America
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24
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Descamps HC, Herrmann B, Wiredu D, Thaiss CA. The path toward using microbial metabolites as therapies. EBioMedicine 2019; 44:747-754. [PMID: 31201140 PMCID: PMC6606739 DOI: 10.1016/j.ebiom.2019.05.063] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/29/2019] [Accepted: 05/30/2019] [Indexed: 12/26/2022] Open
Abstract
Metabolites have emerged as the quintessential effectors mediating the impact of the commensal microbiome on human physiology, both locally at the sites of microbial colonization and systemically. The endocrine activity of the microbiome and its involvement in a multitude of complex diseases has made microbiome-modulated metabolites an attractive target for the development of new therapies. Several properties make metabolites uniquely suited for interventional strategies: natural occurrence in a broad range of concentrations, functional pleiotropy, ease of administration, and tissue bioavailability. Here, we provide an overview of recently discovered physiological effects of microbiome-associated small molecules that may serve as the first examples of metabolite-based therapies. We also highlight challenges and obstacles that the field needs to overcome on the path toward successful clinical trials of microbial metabolites for human disease.
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Affiliation(s)
- Hélène C Descamps
- Microbiology Department, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Beatrice Herrmann
- Microbiology Department, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Daphne Wiredu
- Microbiology Department, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Christoph A Thaiss
- Microbiology Department, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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25
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Wharton S, Bonder R, Jeffery A, Christensen RAG. The safety and effectiveness of commonly-marketed natural supplements for weight loss in populations with obesity: A critical review of the literature from 2006 to 2016. Crit Rev Food Sci Nutr 2019; 60:1614-1630. [PMID: 30896252 DOI: 10.1080/10408398.2019.1584873] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Objective: To evaluate the evidence published from 2006 to 2016 on the effectiveness and safety of commonly used natural supplements for weight loss in individuals with obesity.Methods: Amazon and Google were searched for names of mono-agent natural supplements marketed for weight loss and a list of the 10 supplements was created. Google Scholar, Pubmed, Science Direct, and the Cochrane Library were searched for articles that met inclusion.Results: At least one article was published on the effectiveness or safety of bitter orange, capsinoid, carnitine, chromium picolinate, Coleus forskohlii, conjugated linoleic acid, glucomannan, green tea and psyllium for weight loss in populations with obesity from 2006 to 2016. There was insufficient evidence to suggest that the natural supplements examined contribute to significant weight loss, with the exception of perhaps glucomannan in the form of PGX. In general, the majority of side-effects reported were minor to moderate, and gastrointestinal-related. However, in some cases extreme side-effects such as liver and kidney failure were observed.Conclusion: Contrary to popular belief, results of this review suggest that the use of natural supplements for weight loss are unlikely to contribute to meaningful weight loss and in some cases may contribute to harm.
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Affiliation(s)
- Sean Wharton
- The Wharton Medical Clinic, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - Revi Bonder
- School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - Aaron Jeffery
- The Wharton Medical Clinic, Toronto, Ontario, Canada
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26
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Namazi N, Irandoost P, Larijani B, Azadbakht L. The effects of supplementation with conjugated linoleic acid on anthropometric indices and body composition in overweight and obese subjects: A systematic review and meta-analysis. Crit Rev Food Sci Nutr 2019; 59:2720-2733. [PMID: 29672124 DOI: 10.1080/10408398.2018.1466107] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Clinical trials have indicated conflicting results on the effects of conjugated linoleic acid (CLA) on obesity. The present study aimed to systematically review controlled clinical trials examining the effects of CLA on anthropometric indices and body composition in overweight and obese subjects. Pubmed, Scopus, Web of science, and Cochrane databases were searched between 2000 and December 2017 with no language restriction. Placebo-controlled clinical trials that reported anthropometric indices and body composition in overweight and obese subjects were included. Random-effect model was used to pool the effect estimates. Of 4032 publications, 13 trials were included for the meta-analysis. Pooled effect sizes indicated that CLA significantly reduced body weight (WMD: -0.52 kg, 95% CI: -0.83, -0.21; I2: 48.0%, p = 0.01), BMI (WMD: -0.23 kg/m2, 95% CI: -0.39, - 0.06; I2: 64.7%, p = 0.0001), FM (WMD: -0.61 kg, 95% CI: -0.98, -0.24; I2: 53.8%, p = 0.01) and increased LBM (WMD: 0.19 kg, 95% CI: 0.04, 0.34; I2: 81.4%, p = 0.0001) compared to the placebo group. However, the effects of CLA on WC (WMD: 0.05 cm, 95% CI: -0.01, 0.1; I2: 0%, p = 0.93) was not significant. Additionally, its impact on body weight in subjects older than 44 year (WMD: -1.05 kg, 95% CI: -1.75, -0.35; I2: 57.0%, p = 0.01), with longer duration (more than 12 weeks) (WMD: -1.29 kg, 95% CI: -2.29, -0.29; I2: 70.3%, p = 0.003) and dosage more than 3.4 g/day (WMD: -0.77 kg, 95% CI: -1.28, -0.25; I2: 62.7%, p = 0.004) were greater than comparative groups. Supplementation with CLA can slightly reduce body weight and FM and increase LBM in overweight and obese subjects. However, its efficacy was not clinically considerable. Further studies with high methodological quality are needed to shed light on the effects of CLA on anthropometric indices in overweight and obese subjects.
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Affiliation(s)
- Nazli Namazi
- Obesity and Eating Habits Research Center, Endocrinology and Metabolism Molecular- Cellular Sciences Institute, Tehran University of Medical Sciences , Tehran , Iran
| | - Pardis Irandoost
- Department of Nutrition, School of Public Health, Iran University of Medical Sciences , Tehran , Iran
| | - Bagher Larijani
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences , Tehran , Iran
| | - Leila Azadbakht
- Diabetes Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences , Tehran , Iran.,Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences , Tehran , Iran.,Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences , Isfahan , Iran
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Hooper L, Al‐Khudairy L, Abdelhamid AS, Rees K, Brainard JS, Brown TJ, Ajabnoor SM, O'Brien AT, Winstanley LE, Donaldson DH, Song F, Deane KHO. Omega-6 fats for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev 2018; 11:CD011094. [PMID: 30488422 PMCID: PMC6516799 DOI: 10.1002/14651858.cd011094.pub4] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Omega-6 fats are polyunsaturated fats vital for many physiological functions, but their effect on cardiovascular disease (CVD) risk is debated. OBJECTIVES To assess effects of increasing omega-6 fats (linoleic acid (LA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA) and arachidonic acid (AA)) on CVD and all-cause mortality. SEARCH METHODS We searched CENTRAL, MEDLINE and Embase to May 2017 and clinicaltrials.gov and the World Health Organization International Clinical Trials Registry Platform to September 2016, without language restrictions. We checked trials included in relevant systematic reviews. SELECTION CRITERIA We included randomised controlled trials (RCTs) comparing higher versus lower omega-6 fat intake in adults with or without CVD, assessing effects over at least 12 months. We included full texts, abstracts, trials registry entries and unpublished studies. Outcomes were all-cause mortality, CVD mortality, CVD events, risk factors (blood lipids, adiposity, blood pressure), and potential adverse events. We excluded trials where we could not separate omega-6 fat effects from those of other dietary, lifestyle or medication interventions. DATA COLLECTION AND ANALYSIS Two authors independently screened titles/abstracts, assessed trials for inclusion, extracted data, and assessed risk of bias of included trials. We wrote to authors of included studies. Meta-analyses used random-effects analysis, while sensitivity analyses used fixed-effects and limited analyses to trials at low summary risk of bias. We assessed GRADE quality of evidence for 'Summary of findings' tables. MAIN RESULTS We included 19 RCTs in 6461 participants who were followed for one to eight years. Seven trials assessed the effects of supplemental GLA and 12 of LA, none DGLA or AA; the omega-6 fats usually displaced dietary saturated or monounsaturated fats. We assessed three RCTs as being at low summary risk of bias.Primary outcomes: we found low-quality evidence that increased intake of omega-6 fats may make little or no difference to all-cause mortality (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.88 to 1.12, 740 deaths, 4506 randomised, 10 trials) or CVD events (RR 0.97, 95% CI 0.81 to 1.15, 1404 people experienced events of 4962 randomised, 7 trials). We are uncertain whether increasing omega-6 fats affects CVD mortality (RR 1.09, 95% CI 0.76 to 1.55, 472 deaths, 4019 randomised, 7 trials), coronary heart disease events (RR 0.88, 95% CI 0.66 to 1.17, 1059 people with events of 3997 randomised, 7 trials), major adverse cardiac and cerebrovascular events (RR 0.84, 95% CI 0.59 to 1.20, 817 events, 2879 participants, 2 trials) or stroke (RR 1.36, 95% CI 0.45 to 4.11, 54 events, 3730 participants, 4 trials), as we assessed the evidence as being of very low quality. We found no evidence of dose-response or duration effects for any primary outcome, but there was a suggestion of greater protection in participants with lower baseline omega-6 intake across outcomes.Additional key outcomes: we found increased intake of omega-6 fats may reduce myocardial infarction (MI) risk (RR 0.88, 95% CI 0.76 to 1.02, 609 events, 4606 participants, 7 trials, low-quality evidence). High-quality evidence suggests increasing omega-6 fats reduces total serum cholesterol a little in the long term (mean difference (MD) -0.33 mmol/L, 95% CI -0.50 to -0.16, I2 = 81%; heterogeneity partially explained by dose, 4280 participants, 10 trials). Increasing omega-6 fats probably has little or no effect on adiposity (body mass index (BMI) MD -0.20 kg/m2, 95% CI -0.56 to 0.16, 371 participants, 1 trial, moderate-quality evidence). It may make little or no difference to serum triglycerides (MD -0.01 mmol/L, 95% CI -0.23 to 0.21, 834 participants, 5 trials), HDL (MD -0.01 mmol/L, 95% CI -0.03 to 0.02, 1995 participants, 4 trials) or low-density lipoprotein (MD -0.04 mmol/L, 95% CI -0.21 to 0.14, 244 participants, 2 trials, low-quality evidence). AUTHORS' CONCLUSIONS This is the most extensive systematic assessment of effects of omega-6 fats on cardiovascular health, mortality, lipids and adiposity to date, using previously unpublished data. We found no evidence that increasing omega-6 fats reduces cardiovascular outcomes other than MI, where 53 people may need to increase omega-6 fat intake to prevent 1 person from experiencing MI. Although benefits of omega-6 fats remain to be proven, increasing omega-6 fats may be of benefit in people at high risk of MI. Increased omega-6 fats reduce serum total cholesterol but not other blood fat fractions or adiposity.
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Affiliation(s)
- Lee Hooper
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichNorfolkUKNR4 7TJ
| | - Lena Al‐Khudairy
- Warwick Medical School, University of WarwickDivision of Health SciencesCoventryUKCV4 7AL
| | - Asmaa S Abdelhamid
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichNorfolkUKNR4 7TJ
| | - Karen Rees
- Warwick Medical School, University of WarwickDivision of Health SciencesCoventryUKCV4 7AL
| | - Julii S Brainard
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichNorfolkUKNR4 7TJ
| | - Tracey J Brown
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichNorfolkUKNR4 7TJ
| | - Sarah M Ajabnoor
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichNorfolkUKNR4 7TJ
| | - Alex T O'Brien
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichNorfolkUKNR4 7TJ
| | - Lauren E Winstanley
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichNorfolkUKNR4 7TJ
| | - Daisy H Donaldson
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichNorfolkUKNR4 7TJ
| | - Fujian Song
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichNorfolkUKNR4 7TJ
| | - Katherine HO Deane
- University of East AngliaSchool of Health SciencesColney LaneNorwichUKNR4 7UL
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28
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Accumulation of conjugated linoleic acid in Lactobacillus plantarum WU-P19 is enhanced by induction with linoleic acid and chitosan treatment. ANN MICROBIOL 2018. [DOI: 10.1007/s13213-018-1368-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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Kerksick CM, Wilborn CD, Roberts MD, Smith-Ryan A, Kleiner SM, Jäger R, Collins R, Cooke M, Davis JN, Galvan E, Greenwood M, Lowery LM, Wildman R, Antonio J, Kreider RB. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr 2018; 15:38. [PMID: 30068354 PMCID: PMC6090881 DOI: 10.1186/s12970-018-0242-y] [Citation(s) in RCA: 375] [Impact Index Per Article: 62.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/17/2018] [Indexed: 12/18/2022] Open
Abstract
Background Sports nutrition is a constantly evolving field with hundreds of research papers published annually. In the year 2017 alone, 2082 articles were published under the key words ‘sport nutrition’. Consequently, staying current with the relevant literature is often difficult. Methods This paper is an ongoing update of the sports nutrition review article originally published as the lead paper to launch the Journal of the International Society of Sports Nutrition in 2004 and updated in 2010. It presents a well-referenced overview of the current state of the science related to optimization of training and performance enhancement through exercise training and nutrition. Notably, due to the accelerated pace and size at which the literature base in this research area grows, the topics discussed will focus on muscle hypertrophy and performance enhancement. As such, this paper provides an overview of: 1.) How ergogenic aids and dietary supplements are defined in terms of governmental regulation and oversight; 2.) How dietary supplements are legally regulated in the United States; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of nutritional approaches to augment skeletal muscle hypertrophy and the potential ergogenic value of various dietary and supplemental approaches. Conclusions This updated review is to provide ISSN members and individuals interested in sports nutrition with information that can be implemented in educational, research or practical settings and serve as a foundational basis for determining the efficacy and safety of many common sport nutrition products and their ingredients.
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Affiliation(s)
- Chad M Kerksick
- Exercise and Performance Nutrition Laboratory, School of Health Sciences, Lindenwood University, St. Charles, MO, USA.
| | - Colin D Wilborn
- Exercise & Sport Science Department, University of Mary-Hardin Baylor, Belton, TX, USA
| | | | - Abbie Smith-Ryan
- Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | | | | | - Rick Collins
- Collins Gann McCloskey and Barry PLLC, Mineola, NY, USA
| | - Mathew Cooke
- Department of Health and Medical Sciences, Swinburne University of Technology, Hawthorn, Victoria, Australia
| | - Jaci N Davis
- Exercise & Sport Science Department, University of Mary-Hardin Baylor, Belton, TX, USA
| | - Elfego Galvan
- University of Texas Medical Branch, Galveston, TX, USA
| | - Mike Greenwood
- Exercise & Sports Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX, USA
| | - Lonnie M Lowery
- Department of Human Performance & Sport Business, University of Mount Union, Alliance, OH, USA
| | | | - Jose Antonio
- Department of Health and Human Performance, Nova Southeastern University, Davie, FL, USA
| | - Richard B Kreider
- Exercise & Sports Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX, USA.
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Hooper L, Al‐Khudairy L, Abdelhamid AS, Rees K, Brainard JS, Brown TJ, Ajabnoor SM, O'Brien AT, Winstanley LE, Donaldson DH, Song F, Deane KHO. Omega-6 fats for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev 2018; 7:CD011094. [PMID: 30019765 PMCID: PMC6513455 DOI: 10.1002/14651858.cd011094.pub3] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Omega-6 fats are polyunsaturated fats vital for many physiological functions, but their effect on cardiovascular disease (CVD) risk is debated. OBJECTIVES To assess effects of increasing omega-6 fats (linoleic acid (LA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA) and arachidonic acid (AA)) on CVD and all-cause mortality. SEARCH METHODS We searched CENTRAL, MEDLINE and Embase to May 2017 and clinicaltrials.gov and the World Health Organization International Clinical Trials Registry Platform to September 2016, without language restrictions. We checked trials included in relevant systematic reviews. SELECTION CRITERIA We included randomised controlled trials (RCTs) comparing higher versus lower omega-6 fat intake in adults with or without CVD, assessing effects over at least 12 months. We included full texts, abstracts, trials registry entries and unpublished studies. Outcomes were all-cause mortality, CVD mortality, CVD events, risk factors (blood lipids, adiposity, blood pressure), and potential adverse events. We excluded trials where we could not separate omega-6 fat effects from those of other dietary, lifestyle or medication interventions. DATA COLLECTION AND ANALYSIS Two authors independently screened titles/abstracts, assessed trials for inclusion, extracted data, and assessed risk of bias of included trials. We wrote to authors of included studies. Meta-analyses used random-effects analysis, while sensitivity analyses used fixed-effects and limited analyses to trials at low summary risk of bias. We assessed GRADE quality of evidence for 'Summary of findings' tables. MAIN RESULTS We included 19 RCTs in 6461 participants who were followed for one to eight years. Seven trials assessed the effects of supplemental GLA and 12 of LA, none DGLA or AA; the omega-6 fats usually displaced dietary saturated or monounsaturated fats. We assessed three RCTs as being at low summary risk of bias.Primary outcomes: we found low-quality evidence that increased intake of omega-6 fats may make little or no difference to all-cause mortality (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.88 to 1.12, 740 deaths, 4506 randomised, 10 trials) or CVD events (RR 0.97, 95% CI 0.81 to 1.15, 1404 people experienced events of 4962 randomised, 7 trials). We are uncertain whether increasing omega-6 fats affects CVD mortality (RR 1.09, 95% CI 0.76 to 1.55, 472 deaths, 4019 randomised, 7 trials), coronary heart disease events (RR 0.88, 95% CI 0.66 to 1.17, 1059 people with events of 3997 randomised, 7 trials), major adverse cardiac and cerebrovascular events (RR 0.84, 95% CI 0.59 to 1.20, 817 events, 2879 participants, 2 trials) or stroke (RR 1.36, 95% CI 0.45 to 4.11, 54 events, 3730 participants, 4 trials), as we assessed the evidence as being of very low quality. We found no evidence of dose-response or duration effects for any primary outcome, but there was a suggestion of greater protection in participants with lower baseline omega-6 intake across outcomes.Additional key outcomes: we found increased intake of omega-6 fats may reduce myocardial infarction (MI) risk (RR 0.88, 95% CI 0.76 to 1.02, 609 events, 4606 participants, 7 trials, low-quality evidence). High-quality evidence suggests increasing omega-6 fats reduces total serum cholesterol a little in the long term (mean difference (MD) -0.33 mmol/L, 95% CI -0.50 to -0.16, I2 = 81%; heterogeneity partially explained by dose, 4280 participants, 10 trials). Increasing omega-6 fats probably has little or no effect on adiposity (body mass index (BMI) MD -0.20 kg/m2, 95% CI -0.56 to 0.16, 371 participants, 1 trial, moderate-quality evidence). It may make little or no difference to serum triglycerides (MD -0.01 mmol/L, 95% CI -0.23 to 0.21, 834 participants, 5 trials), HDL (MD -0.01 mmol/L, 95% CI -0.03 to 0.02, 1995 participants, 4 trials) or low-density lipoprotein (MD -0.04 mmol/L, 95% CI -0.21 to 0.14, 244 participants, 2 trials, low-quality evidence). AUTHORS' CONCLUSIONS This is the most extensive systematic assessment of effects of omega-6 fats on cardiovascular health, mortality, lipids and adiposity to date, using previously unpublished data. We found no evidence that increasing omega-6 fats reduces cardiovascular outcomes other than MI, where 53 people may need to increase omega-6 fat intake to prevent 1 person from experiencing MI. Although benefits of omega-6 fats remain to be proven, increasing omega-6 fats may be of benefit in people at high risk of MI. Increased omega-6 fats reduce serum total cholesterol but not other blood fat fractions or adiposity.
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Affiliation(s)
- Lee Hooper
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichUKNR4 7TJ
| | - Lena Al‐Khudairy
- Warwick Medical School, University of WarwickDivision of Health SciencesCoventryUKCV4 7AL
| | - Asmaa S Abdelhamid
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichUKNR4 7TJ
| | - Karen Rees
- Warwick Medical School, University of WarwickDivision of Health SciencesCoventryUKCV4 7AL
| | - Julii S Brainard
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichUKNR4 7TJ
| | - Tracey J Brown
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichUKNR4 7TJ
| | - Sarah M Ajabnoor
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichUKNR4 7TJ
| | - Alex T O'Brien
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichUKNR4 7TJ
| | - Lauren E Winstanley
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichUKNR4 7TJ
| | - Daisy H Donaldson
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichUKNR4 7TJ
| | - Fujian Song
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichUKNR4 7TJ
| | - Katherine HO Deane
- University of East AngliaSchool of Health SciencesColney LaneNorwichUKNR4 7UL
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Coelho OGL, Cândido FG, Alfenas RDCG. Dietary fat and gut microbiota: mechanisms involved in obesity control. Crit Rev Food Sci Nutr 2018; 59:3045-3053. [DOI: 10.1080/10408398.2018.1481821] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
| | - Flávia Galvão Cândido
- Departamento de Nutrição e Saúde, Universidade Federal de Viçosa, Minas Gerais, Brasil
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Mazidi M, Karimi E, Rezaie P, Ferns GA. Effects of conjugated linoleic acid supplementation on serum C-reactive protein: A systematic review and meta-analysis of randomized controlled trials. Cardiovasc Ther 2018; 35. [PMID: 28556504 DOI: 10.1111/1755-5922.12275] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 05/06/2017] [Accepted: 05/22/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To undertake a systematic review and meta-analysis of prospective studies to determine the effect of conjugated linoleic acids (CLAs) supplementation on serum C-reactive protein (CRP). METHOD PubMed-Medline, Web of Science, Cochrane Database, and Google Scholar databases were searched (up until May 2016) to identify prospective studies evaluating the impact of CLAs supplementation on serum CRP. Random-effects models meta-analysis was used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. Heterogeneity was quantitatively assessed using the I2 index. Systematic review registration: CRD42016038945. RESULTS From a total of 85 entries identified via searches, 14 studies were included in the final selection. The meta-analysis indicated a significant increase in serum CRP concentrations following supplementation with CLAs (weighted mean difference [WMD] 0.63 mg/dL, 95% confidence interval [95% CI] 0.13-1.13, N=21 arms, heterogeneity P=.026; I2 =52.3%). These findings were robust in sensitivity analyses. Random-effects meta-regression revealed that changes in serum CRP levels were independent of the dosage of CLAs supplementation (slope: -0.02; 95% CI: -0.10, 0.12; P=.889) or duration of follow-up (slope: 0.271; 95% CI: -0.05, 0.59; P=.098). CONCLUSIONS This meta-analysis suggests that CLA supplementation is associated with an increase in plasma CRP concentrations and a reduction in serum adiponectin concentrations, which indicates that CLA supplements have a proinflammatory effect. Randomized control trials with larger sample size and a longer follow-up period may be required for future investigations to provide an unequivocal answer.
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Affiliation(s)
- Mohsen Mazidi
- Key State Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,Institute of Genetics and Developmental Biology, International College, University of Chinese Academy of Science, Beijing, China
| | - Ehsan Karimi
- Biochemistry of Nutrition Research Center, School of Medicine, Mashhad University of Medical Science, Mashhad, Iran
| | - Peyman Rezaie
- Biochemistry of Nutrition Research Center, School of Medicine, Mashhad University of Medical Science, Mashhad, Iran
| | - Gordon A Ferns
- Division of Medical Education, Brighton and Sussex Medical School, Falmer, Brighton, UK
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Chen PB, Yang JS, Park Y. Adaptations of Skeletal Muscle Mitochondria to Obesity, Exercise, and Polyunsaturated Fatty Acids. Lipids 2018; 53:271-278. [PMID: 29663395 DOI: 10.1002/lipd.12037] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/01/2018] [Accepted: 03/06/2018] [Indexed: 12/22/2022]
Abstract
Mitochondria intricately modulate their energy production through the control of mitochondrial adaptation (mitochondrial biogenesis, fusion, and/or fission) to meet energy demands. Nutrient overload may result in dysregulated mitochondrial biogenesis, morphology toward mitochondrial fragmentation, and oxidative stress in the skeletal muscle. In addition, physical activity and diet components influence mitochondrial function. Exercise may stimulate mitochondrial biogenesis and promote mitochondrial fusion/fission in the skeletal muscle. Moreover, some dietary fatty acids, such as n-3 polyunsaturated fatty acids and conjugated linoleic acid, have been identified to positively regulate mitochondrial adaptation in the skeletal muscle. This review discusses the association of mitochondrial impairments and obesity, and presents an overview of various mechanisms of which exercise training and mitochondrial nutrients promote mitochondrial function in the skeletal muscle.
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Affiliation(s)
- Phoebe B Chen
- Department of Food Science, University of Massachusetts, Amherst, 102 Holdsworth Way, Amherst, MA, 01003, USA
| | - Jason S Yang
- Department of Food Science, University of Massachusetts, Amherst, 102 Holdsworth Way, Amherst, MA, 01003, USA
| | - Yeonhwa Park
- Department of Food Science, University of Massachusetts, Amherst, 102 Holdsworth Way, Amherst, MA, 01003, USA
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34
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Ribeiro SC, Stanton C, Yang B, Ross RP, Silva CC. Conjugated linoleic acid production and probiotic assessment of Lactobacillus plantarum isolated from Pico cheese. Lebensm Wiss Technol 2018. [DOI: 10.1016/j.lwt.2017.12.065] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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35
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Maher T, Clegg ME. Dietary lipids with potential to affect satiety: Mechanisms and evidence. Crit Rev Food Sci Nutr 2018; 59:1619-1644. [DOI: 10.1080/10408398.2017.1423277] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Tyler Maher
- Oxford Brookes Centre for Nutrition and Health, Department of Sport, Health Sciences and Social Work, Faculty of Health and Life Sciences, Oxford Brookes University, Gipsy Lane, Oxford, UK
| | - Miriam E. Clegg
- Oxford Brookes Centre for Nutrition and Health, Department of Sport, Health Sciences and Social Work, Faculty of Health and Life Sciences, Oxford Brookes University, Gipsy Lane, Oxford, UK
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Tremblay BL, Rudkowska I. Nutrigenomic point of view on effects and mechanisms of action of ruminant trans fatty acids on insulin resistance and type 2 diabetes. Nutr Rev 2017; 75:214-223. [PMID: 28340087 DOI: 10.1093/nutrit/nuw066] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Evidence from observational studies suggests beneficial effects of ruminant trans fatty acids (rTFA) on insulin resistance (IR) and type 2 diabetes (T2D). However, beneficial effects of rTFA are not always observed in cell, animal, and human studies. This narrative review presents potential mechanisms of action of rTFA using nutrigenomics and microRNA results in an integrative model. In addition, the review presents factors, including measures of IR and T2D, dose and duration of studies, as well as health status, ethnicity, and genotypes of subjects, that may help explain the heterogeneity in response to rTFA supplementation. Future studies should consider these factors, as well as research in nutritional genomics, to better understand the effects of rTFA on IR and T2D.
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Affiliation(s)
- Bénédicte L Tremblay
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Quebec, Canada
| | - Iwona Rudkowska
- Department of Endocrinology and Nephrology, CHU de Québec Research Center, Quebec City, Quebec, Canada
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37
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Shen W, McIntosh MK. Nutrient Regulation: Conjugated Linoleic Acid's Inflammatory and Browning Properties in Adipose Tissue. Annu Rev Nutr 2017; 36:183-210. [PMID: 27431366 DOI: 10.1146/annurev-nutr-071715-050924] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Obesity is the most widespread nutritional disease in the United States. Developing effective and safe strategies to manage excess body weight is therefore of paramount importance. One potential strategy to reduce obesity is to consume conjugated linoleic acid (CLA) supplements containing isomers cis-9, trans-11 and trans-10, cis-12, or trans-10, cis-12 alone. Proposed antiobesity mechanisms of CLA include regulation of (a) adipogenesis, (b) lipid metabolism, (c) inflammation, (d) adipocyte apoptosis, (e) browning or beiging of adipose tissue, and (f) energy metabolism. However, causality of CLA-mediated responses to body fat loss, particularly the linkage between inflammation, thermogenesis, and energy metabolism, is unclear. This review examines whether CLA's antiobesity properties are due to inflammatory signaling and considers CLA's linkage with lipogenesis, lipolysis, thermogenesis, and browning of white and brown adipose tissue. We propose a series of questions and studies to interrogate the role of the sympathetic nervous system in mediating CLA's antiobesity properties.
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Affiliation(s)
- Wan Shen
- Department of Nutrition, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402; ,
| | - Michael K McIntosh
- Department of Nutrition, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402; ,
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Niezgoda N, Gliszczyńska A, Kempińska K, Wietrzyk J, Wawrzeńczyk C. Synthesis and evaluation of cytotoxic activity of conjugated linoleic acid derivatives (esters, alcohols, and their acetates) toward cancer cell lines. EUR J LIPID SCI TECH 2017. [DOI: 10.1002/ejlt.201600470] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Natalia Niezgoda
- Department of Chemistry; Wrocław University of Environmental and Life Sciences; Wrocław Poland
| | - Anna Gliszczyńska
- Department of Chemistry; Wrocław University of Environmental and Life Sciences; Wrocław Poland
| | - Katarzyna Kempińska
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy; Polish Academy of Sciences; Wrocław Poland
| | - Joanna Wietrzyk
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy; Polish Academy of Sciences; Wrocław Poland
| | - Czesław Wawrzeńczyk
- Department of Chemistry; Wrocław University of Environmental and Life Sciences; Wrocław Poland
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39
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Metabolic role of lactobacilli in weight modification in humans and animals. Microb Pathog 2017; 106:182-194. [DOI: 10.1016/j.micpath.2016.03.006] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 03/11/2016] [Accepted: 03/22/2016] [Indexed: 02/07/2023]
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Abstract
AbstractSystemic lupus erythematosus (SLE) is a chronic inflammatory and autoimmune disease characterised by multiple organ involvement and a large number of complications. SLE management remains complicated owing to the biological heterogeneity between patients and the lack of safe and specific targeted therapies. There is evidence that dietary factors can contribute to the geoepidemiology of autoimmune diseases such as SLE. Thus, diet therapy could be a promising approach in SLE owing to both its potential prophylactic effects, without the side effects of classical pharmacology, and its contribution to reducing co-morbidities and improving quality of life in patients with SLE. However, the question arises as to whether nutrients could ameliorate or exacerbate SLE and how they could modulate inflammation and immune function at a molecular level. The present review summarises preclinical and clinical experiences to provide the reader with an update of the positive and negative aspects of macro- and micronutrients and other nutritional factors, including dietary phenols, on SLE, focusing on the mechanisms of action involved.
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Paniagua JA. Nutrition, insulin resistance and dysfunctional adipose tissue determine the different components of metabolic syndrome. World J Diabetes 2016; 7:483-514. [PMID: 27895819 PMCID: PMC5107710 DOI: 10.4239/wjd.v7.i19.483] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 08/16/2016] [Accepted: 09/07/2016] [Indexed: 02/05/2023] Open
Abstract
Obesity is an excessive accumulation of body fat that may be harmful to health. Today, obesity is a major public health problem, affecting in greater or lesser proportion all demographic groups. Obesity is estimated by body mass index (BMI) in a clinical setting, but BMI reports neither body composition nor the location of excess body fat. Deaths from cardiovascular diseases, cancer and diabetes accounted for approximately 65% of all deaths, and adiposity and mainly abdominal adiposity are associated with all these disorders. Adipose tissue could expand to inflexibility levels. Then, adiposity is associated with a state of low-grade chronic inflammation, with increased tumor necrosis factor-α and interleukin-6 release, which interfere with adipose cell differentiation, and the action pattern of adiponectin and leptin until the adipose tissue begins to be dysfunctional. In this state the subject presents insulin resistance and hyperinsulinemia, probably the first step of a dysfunctional metabolic system. Subsequent to central obesity, insulin resistance, hyperglycemia, hypertriglyceridemia, hypoalphalipoproteinemia, hypertension and fatty liver are grouped in the so-called metabolic syndrome (MetS). In subjects with MetS an energy balance is critical to maintain a healthy body weight, mainly limiting the intake of high energy density foods (fat). However, high-carbohydrate rich (CHO) diets increase postprandial peaks of insulin and glucose. Triglyceride-rich lipoproteins are also increased, which interferes with reverse cholesterol transport lowering high-density lipoprotein cholesterol. In addition, CHO-rich diets could move fat from peripheral to central deposits and reduce adiponectin activity in peripheral adipose tissue. All these are improved with monounsaturated fatty acid-rich diets. Lastly, increased portions of ω-3 and ω-6 fatty acids also decrease triglyceride levels, and complement the healthy diet that is recommended in patients with MetS.
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Silva‐Ramírez AS, Rocha‐Uribe A, González‐Chávez MM, González C. Synthesis of conjugated linoleic acid by microwave‐assisted alkali isomerization using propylene glycol as solvent. EUR J LIPID SCI TECH 2016. [DOI: 10.1002/ejlt.201600079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
| | - Alejandro Rocha‐Uribe
- Facultad de Ciencias QuímicasUniversidad Autónoma de San Luis PotosíSan Luis PotosíMexico
| | | | - Carmen González
- Facultad de Ciencias QuímicasUniversidad Autónoma de San Luis PotosíSan Luis PotosíMexico
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Kuhl GC, De Dea Lindner J. Biohydrogenation of Linoleic Acid by Lactic Acid Bacteria for the Production of Functional Cultured Dairy Products: A Review. Foods 2016; 5:foods5010013. [PMID: 28231108 PMCID: PMC5224569 DOI: 10.3390/foods5010013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 02/01/2016] [Accepted: 02/15/2016] [Indexed: 11/16/2022] Open
Abstract
Conjugated linoleic acid (CLA) isomers have attracted significant attention due to their important physiological properties, which have been observed in humans. Many lactic acid bacteria (LAB) demonstrate the ability to produce CLA isomers (C18:2 cis-9, trans-11 and C18:2 trans-10, cis-12) from the linoleic acid (LA) present in milk or in synthetic media. CLA isomers can be synthesized in vitro by LAB using vegetable oils rich in LA. The aim of this review is to present an update on the studies that have been conducted on the production of CLA isomers from LA mainly by LAB and of the factors that influence this conversion (source and concentration of LA and fermentation conditions). In addition, this review presents the relationship between the consumption of CLA isomers and their health benefits in humans such as anti-atherosclerosis and anti-carcinogenic effects. There is considerable variation between the studies concerning the beneficial effects of CLA in animal models, which have not been reflected in human studies. This can be attributed to the differences in the doses of CLA isomers used and to the different sources of CLA. Furthermore, the regulatory and scientific information classifying the physiological properties of CLA, which serve as support for the claims of its potential as a functional ingredient, are presented. More research is needed to determine whether CLA production by LAB can be enhanced and to determine the optimal requirements for these microbial cultures. Furthermore, safety and efficacy of CLA consumption have to be investigated in the future.
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Affiliation(s)
- Gabriela Christina Kuhl
- Food Science and Technology Department, Federal University of Santa Catarina, Florianópolis 88034-001, Brazil.
| | - Juliano De Dea Lindner
- Food Science and Technology Department, Federal University of Santa Catarina, Florianópolis 88034-001, Brazil.
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Kim Y, Kim J, Whang KY, Park Y. Impact of Conjugated Linoleic Acid (CLA) on Skeletal Muscle Metabolism. Lipids 2016; 51:159-78. [PMID: 26729488 DOI: 10.1007/s11745-015-4115-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/16/2015] [Indexed: 12/17/2022]
Abstract
Conjugated linoleic acid (CLA) has garnered special attention as a food bioactive compound that prevents and attenuates obesity. Although most studies on the effects of CLA on obesity have focused on the reduction of body fat, a number of studies have demonstrated that CLA also increases lean body mass and enhances physical performances. It has been suggested that these effects may be due in part to physiological changes in the skeletal muscle, such as changes in the muscle fiber type transformation, alteration of the intracellular signaling pathways in muscle metabolism, or energy metabolism. However, the mode of action for CLA in muscle metabolism is not completely understood. The purpose of this review is to summarize the current knowledge of the effects of CLA on skeletal muscle metabolism. Given that CLA not only reduces body fat, but also improves lean mass, there is great potential for the use of CLA to improve muscle metabolism, which would have a significant health impact.
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Affiliation(s)
- Yoo Kim
- Department of Food Science, University of Massachusetts, 102 Holdsworth Way, Amherst, MA, 01003, USA
| | - Jonggun Kim
- Division of Biotechnology, Korea University, Seoul, 136-713, Republic of Korea
| | - Kwang-Youn Whang
- Division of Biotechnology, Korea University, Seoul, 136-713, Republic of Korea
| | - Yeonhwa Park
- Department of Food Science, University of Massachusetts, 102 Holdsworth Way, Amherst, MA, 01003, USA.
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Al-Khudairy L, Hartley L, Clar C, Flowers N, Hooper L, Rees K. Omega 6 fatty acids for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev 2015:CD011094. [PMID: 26571451 DOI: 10.1002/14651858.cd011094.pub2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Omega 6 plays a vital role in many physiological functions but there is controversy concerning its effect on cardiovascular disease (CVD) risk. There is conflicting evidence whether increasing or decreasing omega 6 intake results in beneficial effects. OBJECTIVES The two primary objectives of this Cochrane review were to determine the effectiveness of:1. Increasing omega 6 (Linoleic acid (LA), Gamma-linolenic acid (GLA), Dihomo-gamma-linolenic acid (DGLA), Arachidonic acid (AA), or any combination) intake in place of saturated or monounsaturated fats or carbohydrates for the primary prevention of CVD.2. Decreasing omega 6 (LA, GLA, DGLA, AA, or any combination) intake in place of carbohydrates or protein (or both) for the primary prevention of CVD. SEARCH METHODS We searched the following electronic databases up to 23 September 2014: the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library (Issue 8 of 12, 2014); MEDLINE (Ovid) (1946 to September week 2, 2014); EMBASE Classic and EMBASE (Ovid) (1947 to September 2014); Web of Science Core Collection (Thomson Reuters) (1990 to September 2014); Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment Database, and Health Economics Evaluations Database on the Cochrane Library (Issue 3 of 4, 2014). We searched trial registers and reference lists of reviews for further studies. We applied no language restrictions. SELECTION CRITERIA Randomised controlled trials (RCTs) of interventions stating an intention to increase or decrease omega 6 fatty acids, lasting at least six months, and including healthy adults or adults at high risk of CVD. The comparison group was given no advice, no supplementation, a placebo, a control diet, or continued with their usual diet. The outcomes of interest were CVD clinical events (all-cause mortality, cardiovascular mortality, non-fatal end points) and CVD risk factors (changes in blood pressure, changes in blood lipids, occurrence of type 2 diabetes). We excluded trials involving exercise or multifactorial interventions to avoid confounding. DATA COLLECTION AND ANALYSIS Two review authors independently selected trials for inclusion, extracted the data, and assessed the risk of bias in the included trials. MAIN RESULTS We included four RCTs (five papers) that randomised 660 participants. No ongoing trials were identified. All included trials had at least one domain with an unclear risk of bias. There were no RCTs of omega 6 intake reporting CVD clinical events. Three trials investigated the effect of increased omega 6 intake on lipid levels (total cholesterol, low density lipoprotein (LDL-cholesterol), and high density lipoprotein (HDL-cholesterol)), two trials reported triglycerides, and two trials reported blood pressure (diastolic and systolic blood pressure). Two trials, one with two relevant intervention arms, investigated the effect of decreased omega 6 intake on blood pressure parameters and lipid levels (total cholesterol, LDL-cholesterol, and HDL-cholesterol) and one trial reported triglycerides. Our analyses found no statistically significant effects of either increased or decreased omega 6 intake on CVD risk factors.Two studies were supported by funding from the UK Food Standards Agency and Medical Research Council. One study was supported by Lipid Nutrition, a commercial company in the Netherlands and the Dutch Ministry of Economic Affairs. The final study was supported by grants from the Finnish Food Research Foundation, Finnish Heart Research Foundation, Aarne and Aili Turnen Foundation, and the Research Council for Health, Academy of Finland. AUTHORS' CONCLUSIONS We found no studies examining the effects of either increased or decreased omega 6 on our primary outcome CVD clinical endpoints and insufficient evidence to show an effect of increased or decreased omega 6 intake on CVD risk factors such as blood lipids and blood pressure. Very few trials were identified with a relatively small number of participants randomised. There is a need for larger well conducted RCTs assessing cardiovascular events as well as cardiovascular risk factors.
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Affiliation(s)
- Lena Al-Khudairy
- Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK, CV4 7AL
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Hooper L, Abdelhamid A, Bunn D, Brown T, Summerbell CD, Skeaff CM. Effects of total fat intake on body weight. Cochrane Database Syst Rev 2015:CD011834. [PMID: 26250104 PMCID: PMC10403157 DOI: 10.1002/14651858.cd011834] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND In order to prevent overweight and obesity in the general population we need to understand the relationship between the proportion of energy from fat and resulting weight and body fatness in the general population. OBJECTIVES To assess the effects of proportion of energy intake from fat on measures of weight and body fatness (including obesity, waist circumference and body mass index) in people not aiming to lose weight, using all appropriate randomised controlled trials (RCTs) and cohort studies in adults, children and young people SEARCH METHODS We searched CENTRAL to March 2014 and MEDLINE, EMBASE and CINAHL to November 2014. We did not limit the search by language. We also checked the references of relevant reviews. SELECTION CRITERIA Trials fulfilled the following criteria: 1) randomised intervention trial, 2) included children (aged ≥ 24 months), young people or adults, 3) randomised to a lower fat versus usual or moderate fat diet, without the intention to reduce weight in any participants, 4) not multifactorial and 5) assessed a measure of weight or body fatness after at least six months. We also included cohort studies in children, young people and adults that assessed the proportion of energy from fat at baseline and assessed the relationship with body weight or fatness after at least one year. We duplicated inclusion decisions and resolved disagreement by discussion or referral to a third party. DATA COLLECTION AND ANALYSIS We extracted data on the population, intervention, control and outcome measures in duplicate. We extracted measures of weight and body fatness independently in duplicate at all available time points. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity and funnel plot analyses. MAIN RESULTS We included 32 RCTs (approximately 54,000 participants) and 30 sets of analyses of 25 cohorts. There is consistent evidence from RCTs in adults of a small weight-reducing effect of eating a smaller proportion of energy from fat; this was seen in almost all included studies and was highly resistant to sensitivity analyses. The effect of eating less fat (compared with usual diet) is a mean weight reduction of 1.5 kg (95% confidence interval (CI) -2.0 to -1.1 kg), but greater weight loss results from greater fat reductions. The size of the effect on weight does not alter over time and is mirrored by reductions in body mass index (BMI) (-0.5 kg/m(2), 95% CI -0.7 to -0.3) and waist circumference (-0.3 cm, 95% CI -0.6 to -0.02). Included cohort studies in children and adults most often do not suggest any relationship between total fat intake and later measures of weight, body fatness or change in body fatness. However, there was a suggestion that lower fat intake was associated with smaller increases in weight in middle-aged but not elderly adults, and in change in BMI in the highest validity child cohort. AUTHORS' CONCLUSIONS Trials where participants were randomised to a lower fat intake versus usual or moderate fat intake, but with no intention to reduce weight, showed a consistent, stable but small effect of low fat intake on body fatness: slightly lower weight, BMI and waist circumference compared with controls. Greater fat reduction and lower baseline fat intake were both associated with greater reductions in weight. This effect of reducing total fat was not consistently reflected in cohort studies assessing the relationship between total fat intake and later measures of body fatness or change in body fatness in studies of children, young people or adults.
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Affiliation(s)
- Lee Hooper
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, UK, NR4 7TJ
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Linoleic Acid Induced Acute Hepatitis: A Case Report and Review of the Literature. Case Reports Hepatol 2015; 2015:807354. [PMID: 26240766 PMCID: PMC4512593 DOI: 10.1155/2015/807354] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 06/25/2015] [Accepted: 06/28/2015] [Indexed: 11/17/2022] Open
Abstract
Several dietary supplements used for weight loss have been reported to cause hepatotoxicity. Conjugated Linoleic Acid (CLA) is a dietary supplement that has been shown to cause reduction in body fat mass. Here, we present the first case of CLA induced acute hepatitis in the United States and only the third case in the worldwide literature along with a brief review of the literature.
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Should the pharmacological actions of dietary fatty acids in cardiometabolic disorders be classified based on biological or chemical function? Prog Lipid Res 2015. [DOI: 10.1016/j.plipres.2015.07.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Hooper L, Martin N, Abdelhamid A, Davey Smith G. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database Syst Rev 2015:CD011737. [PMID: 26068959 DOI: 10.1002/14651858.cd011737] [Citation(s) in RCA: 226] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally it is unclear whether the energy from saturated fats that are lost in the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein. This review is part of a series split from and updating an overarching review. OBJECTIVES To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO), polyunsaturated (PUFA) or monounsaturated fat (MUFA) and/or protein on mortality and cardiovascular morbidity, using all available randomised clinical trials. SEARCH METHODS We updated our searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and EMBASE (Ovid) on 5 March 2014. We also checked references of included studies and reviews. SELECTION CRITERIA Trials fulfilled the following criteria: 1) randomised with appropriate control group; 2) intention to reduce saturated fat intake OR intention to alter dietary fats and achieving a reduction in saturated fat; 3) not multifactorial; 4) adult humans with or without cardiovascular disease (but not acutely ill, pregnant or breastfeeding); 5) intervention at least 24 months; 6) mortality or cardiovascular morbidity data available. DATA COLLECTION AND ANALYSIS Two review authors working independently extracted participant numbers experiencing health outcomes in each arm, and we performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity analyses and funnel plots. MAIN RESULTS We include 15 randomised controlled trials (RCTs) (17 comparisons, ˜59,000 participants), which used a variety of interventions from providing all food to advice on how to reduce saturated fat. The included long-term trials suggested that reducing dietary saturated fat reduced the risk of cardiovascular events by 17% (risk ratio (RR) 0.83; 95% confidence interval (CI) 0.72 to 0.96, 13 comparisons, 53,300 participants of whom 8% had a cardiovascular event, I² 65%, GRADE moderate quality of evidence), but effects on all-cause mortality (RR 0.97; 95% CI 0.90 to 1.05; 12 trials, 55,858 participants) and cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 12 trials, 53,421 participants) were less clear (both GRADE moderate quality of evidence). There was some evidence that reducing saturated fats reduced the risk of myocardial infarction (fatal and non-fatal, RR 0.90; 95% CI 0.80 to 1.01; 11 trials, 53,167 participants), but evidence for non-fatal myocardial infarction (RR 0.95; 95% CI 0.80 to 1.13; 9 trials, 52,834 participants) was unclear and there were no clear effects on stroke (any stroke, RR 1.00; 95% CI 0.89 to 1.12; 8 trials, 50,952 participants). These relationships did not alter with sensitivity analysis. Subgrouping suggested that the reduction in cardiovascular events was seen in studies that primarily replaced saturated fat calories with polyunsaturated fat, and no effects were seen in studies replacing saturated fat with carbohydrate or protein, but effects in studies replacing with monounsaturated fats were unclear (as we located only one small trial). Subgrouping and meta-regression suggested that the degree of reduction in cardiovascular events was related to the degree of reduction of serum total cholesterol, and there were suggestions of greater protection with greater saturated fat reduction or greater increase in polyunsaturated and monounsaturated fats. There was no evidence of harmful effects of reducing saturated fat intakes on cancer mortality, cancer diagnoses or blood pressure, while there was some evidence of improvements in weight and BMI. AUTHORS' CONCLUSIONS The findings of this updated review are suggestive of a small but potentially important reduction in cardiovascular risk on reduction of saturated fat intake. Replacing the energy from saturated fat with polyunsaturated fat appears to be a useful strategy, and replacement with carbohydrate appears less useful, but effects of replacement with monounsaturated fat were unclear due to inclusion of only one small trial. This effect did not appear to alter by study duration, sex or baseline level of cardiovascular risk. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturated fats. The ideal type of unsaturated fat is unclear.
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Affiliation(s)
- Lee Hooper
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, UK, NR4 7TJ
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Kim JH, Kim YJ, Park Y. Conjugated Linoleic Acid and Postmenopausal Women's Health. J Food Sci 2015; 80:R1137-43. [DOI: 10.1111/1750-3841.12905] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/16/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Jun Ho Kim
- Dept. of Food and Biotechnology; Korea Univ; Sejong 339-700 Republic of Korea
| | - Young Jun Kim
- Dept. of Food and Biotechnology; Korea Univ; Sejong 339-700 Republic of Korea
| | - Yeonhwa Park
- Dept. of Food Science; Univ. of Massachusetts; Amherst MA 01003 U.S.A
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