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Szendi K, Murányi E, Hunter N, Németh B. Methodological Challenges and Confounders in Research on the Effects of Ketogenic Diets: A Literature Review of Meta-Analyses. Foods 2024; 13:248. [PMID: 38254549 PMCID: PMC10814162 DOI: 10.3390/foods13020248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/04/2024] [Accepted: 01/11/2024] [Indexed: 01/24/2024] Open
Abstract
Several meta-analyses have found a positive association between a popular type of "fad diet", ketogenic diets, and their effect on anthropometric and blood parameters. However, the non-specific inclusion criteria for meta-analyses may lead to incorrect conclusions. The aim of this literature review is to highlight the main confounders and methodological pitfalls of meta-analyses on ketogenic diets by inspecting the presence of key inclusion criteria. The PubMed, Embase, and Web of Science databases and the Cochrane Database of Systematic Reviews were searched for meta-analyses. Most meta-analyses did not define the essential parameters of a ketogenic diet (i.e., calories, macronutrient ratio, types of fatty acids, ketone bodies, etc.) as inclusion criteria. Of the 28 included meta-analyses, few addressed collecting real, re-measured nutritional data from the ketogenic diet and control groups in parallel with the pre-designed nutritional data. Most meta-analyses reported positive results in favor of ketogenic diets, which can result in erroneous conclusions considering the numerous methodological pitfalls and confounders. Well-designed clinical trials with comparable results and their meta-analyses are needed. Until then, medical professionals should not recommend ketogenic diets as a form of weight loss when other well-known dietary options have been shown to be healthy and effective.
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Affiliation(s)
- Katalin Szendi
- Department of Public Health Medicine, Medical School, University of Pécs, 7624 Pécs, Hungary
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Chen S, Su X, Feng Y, Li R, Liao M, Fan L, Liu J, Chen S, Zhang S, Cai J, Zhu S, Niu J, Ye Y, Lo K, Zeng F. Ketogenic Diet and Multiple Health Outcomes: An Umbrella Review of Meta-Analysis. Nutrients 2023; 15:4161. [PMID: 37836444 PMCID: PMC10574428 DOI: 10.3390/nu15194161] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/22/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023] Open
Abstract
Numerous studies have examined the effects of ketogenic diets (KD) on health-related outcomes through meta-analyses. However, the presence of biases may compromise the reliability of conclusions. Therefore, we conducted an umbrella review to collate and appraise the strength of evidence on the efficacy of KD interventions. We conducted a comprehensive search on PubMed, EMBASE, and the Cochrane Database until April 2023 to identify meta-analyses that investigated the treatment effects of KD for multiple health conditions, which yielded 23 meta-analyses for quantitative analyses. The evidence suggests that KD could increase the levels of low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C), the respiratory exchange rate (RER), and could decrease total testosterone and testosterone levels (all p-random effects: <0.05). The combination of KD and physical activity can significantly reduce body weight and increase the levels of LDL-C and cortisol. In addition, KD was associated with seizure reduction in children, which can be explained by the ketosis state as induced by the diet. Furthermore, KD demonstrated a better alleviation effect in refractory childhood epilepsy, in terms of median effective rates for seizure reduction of ≥50%, ≥90%, and seizure freedom. However, the strength of evidence supporting the aforementioned associations was generally weak, thereby challenging their credibility. Consequently, future studies should prioritize stringent research protocols to ascertain whether KD interventions with longer intervention periods hold promise as a viable treatment option for various diseases.
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Affiliation(s)
- Shiyun Chen
- Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, No. 601 Huangpu Road West, Guangzhou 510632, China; (S.C.); (X.S.); (Y.F.); (R.L.); (J.L.); (S.C.); (S.Z.); (J.C.); (S.Z.)
| | - Xin Su
- Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, No. 601 Huangpu Road West, Guangzhou 510632, China; (S.C.); (X.S.); (Y.F.); (R.L.); (J.L.); (S.C.); (S.Z.); (J.C.); (S.Z.)
| | - Yonghui Feng
- Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, No. 601 Huangpu Road West, Guangzhou 510632, China; (S.C.); (X.S.); (Y.F.); (R.L.); (J.L.); (S.C.); (S.Z.); (J.C.); (S.Z.)
| | - Ruojie Li
- Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, No. 601 Huangpu Road West, Guangzhou 510632, China; (S.C.); (X.S.); (Y.F.); (R.L.); (J.L.); (S.C.); (S.Z.); (J.C.); (S.Z.)
| | - Minqi Liao
- Institute of Epidemiology, Helmholtz Zentrum Munich-German Research Center for Environmental Health, Ingolstadt Landstr. 1, 85764 Neuherberg, Germany;
| | - Laina Fan
- Department of Clinical Medicine, International School, Jinan University, No. 601 Huangpu Road West, Guangzhou 510632, China;
| | - Jiazi Liu
- Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, No. 601 Huangpu Road West, Guangzhou 510632, China; (S.C.); (X.S.); (Y.F.); (R.L.); (J.L.); (S.C.); (S.Z.); (J.C.); (S.Z.)
| | - Shasha Chen
- Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, No. 601 Huangpu Road West, Guangzhou 510632, China; (S.C.); (X.S.); (Y.F.); (R.L.); (J.L.); (S.C.); (S.Z.); (J.C.); (S.Z.)
| | - Shiwen Zhang
- Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, No. 601 Huangpu Road West, Guangzhou 510632, China; (S.C.); (X.S.); (Y.F.); (R.L.); (J.L.); (S.C.); (S.Z.); (J.C.); (S.Z.)
| | - Jun Cai
- Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, No. 601 Huangpu Road West, Guangzhou 510632, China; (S.C.); (X.S.); (Y.F.); (R.L.); (J.L.); (S.C.); (S.Z.); (J.C.); (S.Z.)
| | - Sui Zhu
- Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, No. 601 Huangpu Road West, Guangzhou 510632, China; (S.C.); (X.S.); (Y.F.); (R.L.); (J.L.); (S.C.); (S.Z.); (J.C.); (S.Z.)
| | - Jianxiang Niu
- General Surgery, The Affiliated Hospital of Inner Mongolia Medical University, No. 1 Tongdao North Road, Hohhot 010000, China;
| | - Yanbin Ye
- Department of Clinical Nutrition, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China;
| | - Kenneth Lo
- Department of Food Science and Nutrition, The Hong Kong Polytechnic University, Kowloon, Hong Kong 100872, China
- Research Institute for Future Food, The Hong Kong Polytechnic University, Kowloon, Hong Kong 100872, China
| | - Fangfang Zeng
- Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, No. 601 Huangpu Road West, Guangzhou 510632, China; (S.C.); (X.S.); (Y.F.); (R.L.); (J.L.); (S.C.); (S.Z.); (J.C.); (S.Z.)
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Patikorn C, Saidoung P, Pham T, Phisalprapa P, Lee YY, Varady KA, Veettil SK, Chaiyakunapruk N. Effects of ketogenic diet on health outcomes: an umbrella review of meta-analyses of randomized clinical trials. BMC Med 2023; 21:196. [PMID: 37231411 DOI: 10.1186/s12916-023-02874-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 04/19/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND Systematic reviews and meta-analyses of randomized clinical trials (RCTs) have reported the benefits of ketogenic diets (KD) in various participants such as patients with epilepsy and adults with overweight or obesity. Nevertheless, there has been little synthesis of the strength and quality of this evidence in aggregate. METHODS To grade the evidence from published meta-analyses of RCTs that assessed the association of KD, ketogenic low-carbohydrate high-fat diet (K-LCHF), and very low-calorie KD (VLCKD) with health outcomes, PubMed, EMBASE, Epistemonikos, and Cochrane database of systematic reviews were searched up to February 15, 2023. Meta-analyses of RCTs of KD were included. Meta-analyses were re-performed using a random-effects model. The quality of evidence per association provided in meta-analyses was rated by the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) criteria as high, moderate, low, and very low. RESULTS We included 17 meta-analyses comprising 68 RCTs (median [interquartile range, IQR] sample size of 42 [20-104] participants and follow-up period of 13 [8-36] weeks) and 115 unique associations. There were 51 statistically significant associations (44%) of which four associations were supported by high-quality evidence (reduced triglyceride (n = 2), seizure frequency (n = 1) and increased low-density lipoprotein cholesterol (LDL-C) (n = 1)) and four associations supported by moderate-quality evidence (decrease in body weight, respiratory exchange ratio (RER), hemoglobin A1c, and increased total cholesterol). The remaining associations were supported by very low (26 associations) to low (17 associations) quality evidence. In overweight or obese adults, VLCKD was significantly associated with improvement in anthropometric and cardiometabolic outcomes without worsening muscle mass, LDL-C, and total cholesterol. K-LCHF was associated with reduced body weight and body fat percentage, but also reduced muscle mass in healthy participants. CONCLUSIONS This umbrella review found beneficial associations of KD supported by moderate to high-quality evidence on seizure and several cardiometabolic parameters. However, KD was associated with a clinically meaningful increase in LDL-C. Clinical trials with long-term follow-up are warranted to investigate whether the short-term effects of KD will translate to beneficial effects on clinical outcomes such as cardiovascular events and mortality.
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Affiliation(s)
- Chanthawat Patikorn
- Department of Pharmacotherapy, College of Pharmacy, University of Utah, 30 2000 E, Salt Lake City, Utah, 84112, USA
- Department of Social and Administrative Pharmacy, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Pantakarn Saidoung
- Department of Pharmacotherapy, College of Pharmacy, University of Utah, 30 2000 E, Salt Lake City, Utah, 84112, USA
| | - Tuan Pham
- Division of Gastroenterology, Hepatology & Nutrition, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Pochamana Phisalprapa
- Division of Ambulatory Medicine, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Yeong Yeh Lee
- School of Medical Sciences, Universiti Sains Malaysia, Kota Bharu, Malaysia
| | - Krista A Varady
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Sajesh K Veettil
- Department of Pharmacotherapy, College of Pharmacy, University of Utah, 30 2000 E, Salt Lake City, Utah, 84112, USA.
| | - Nathorn Chaiyakunapruk
- Department of Pharmacotherapy, College of Pharmacy, University of Utah, 30 2000 E, Salt Lake City, Utah, 84112, USA.
- IDEAS Center, Veterans Affairs Salt Lake City Healthcare System, Salt Lake City, Utah, USA.
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Severe Dyslipidemia Mimicking Familial Hypercholesterolemia Induced by High-Fat, Low-Carbohydrate Diets: A Critical Review. Nutrients 2023; 15:nu15040962. [PMID: 36839320 PMCID: PMC9964047 DOI: 10.3390/nu15040962] [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] [Received: 01/04/2023] [Revised: 02/04/2023] [Accepted: 02/07/2023] [Indexed: 02/17/2023] Open
Abstract
Emerging studies in the literature describe an association between high-fat, low-carbohydrate diets and severe hypercholesterolemia consistent with the levels observed in patients with (homozygous) familial hypercholesterolemia (FH). High levels of low-density lipoprotein cholesterol (LDL-C) may result from the reduced clearance of LDL particles from the circulation, the increased production of their precursor, or a combination of both. The increased intake of (saturated) fat and cholesterol, combined with limited to no intake of carbohydrates and fiber, are the main features of diets linked to hypercholesterolemia. However, several observations in previous studies, together with our observations from our lipid clinic, do not provide a definitive pathophysiological explanation for severe hypercholesterolemia. Therefore, we review these findings and possible pathophysiological explanations as well as opportunities for future research. Altogether, clinicians should rule out high-fat, low-carbohydrate diets as a possible cause for hypercholesterolemia in patients presenting with clinical FH in whom no mutation is found and discuss dietary modifications to durably reduce LDL-C levels and cardiovascular disease risk.
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Wang Y, Zhou K, Wang V, Bao D, Zhou J. The Effects of Concurrent Training Combined with Low-Carbohydrate High-Fat Ketogenic Diet on Body Composition and Aerobic Performance: A Systematic Review and Meta-Analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph191811542. [PMID: 36141816 PMCID: PMC9517144 DOI: 10.3390/ijerph191811542] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/05/2022] [Accepted: 09/07/2022] [Indexed: 05/22/2023]
Abstract
(1) Background: Recently, studies have emerged to explore the effects of concurrent training (CT) with a low-carb, high-fat ketogenic diet (LCHF) on body composition and aerobic performance and observed its benefits. However, a large variance in the study design and observations is presented, which needs to be comprehensively assessed. We here thus completed a systematic review and meta-analysis to characterize the effects of the intervention combining CT and LCHF on body composition and aerobic capacity in people with training experience as compared to that combining CT and other dietary strategies. (2) Methods: A search strategy based on the PICOS principle was used to find literature in the databases of PubMed, Web of Science, EBSCO, Sport-discuss, and Medline. The quality and risk of bias in the studies were independently assessed by two researchers. (3) Result: Eight studies consisting of 170 participants were included in this work. The pooled results showed no significant effects of CT with LCHF on lean mass (SMD = -0.08, 95% CI -0.44 to 0.3, p = 0.69), body fat percentage (SMD = -0.29, 95% CI -0.66 to 0.08, p = 0.13), body mass (SMD = -0.21, 95% CI -0.53 to 0.11, p = 0.2), VO2max (SMD = -0.01, 95% CI -0.4 to 0.37, p = 0.95), and time (or distance) to complete the aerobic tests (SMD = -0.02, 95% CI -0.41 to 0.37, p = 0.1). Subgroup analyses also showed that the training background of participants (i.e., recreationally trained participants or professionally trained participants) and intervention duration (e.g., > or ≤six weeks) did not significantly affect the results. (4) Conclusions: This systematic review and meta-analysis provide evidence that compared to other dietary strategies, using LCHF with CT cannot induce greater benefits for lean mass, body fat percentage, body mass, VO2max, and aerobic performance in trained participants.
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Affiliation(s)
- Yubo Wang
- China Institute of Sport and Health Science, Beijing Sport University, Beijing 100084, China
| | - Kaixiang Zhou
- Sports Health College, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
- Correspondence: (K.Z.); (D.B.); Tel.: +86-178-4459-7198 (K.Z.); +86-139-1199-5047 (D.B.)
| | - Vienna Wang
- College of Engineering, California State University, 1250 Bellflower Boulevard, Long Beach, CA 90840, USA
| | - Dapeng Bao
- China Institute of Sport and Health Science, Beijing Sport University, Beijing 100084, China
- Correspondence: (K.Z.); (D.B.); Tel.: +86-178-4459-7198 (K.Z.); +86-139-1199-5047 (D.B.)
| | - Junhong Zhou
- Hebrew Senior Life Hinda and Arthur Marcus Institute for Aging Research, Harvard Medical School, Boston, MA 02115, USA
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Association between depressive symptoms and pericardial fat in healthy older men and women. Sci Rep 2022; 12:13959. [PMID: 35978037 PMCID: PMC9385858 DOI: 10.1038/s41598-022-17888-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 08/02/2022] [Indexed: 12/02/2022] Open
Abstract
Depressive symptoms are associated with increased risk for cardiovascular disease (CVD), and inflammation may contribute to this relationship. Pericardial fat, a highly metabolically active fat depot, is implicated in the pathogenesis of CVD, but its association with depressive symptoms is unclear. This study examined the cross-sectional and longitudinal association between depressive symptoms and pericardial fat over a three-year period. Participants were 543 healthy men and women (mean age = 62.9 years) without history or objective signs of coronary heart disease from the Whitehall II cohort. In men, depressive symptoms were positively associated with pericardial fat at baseline after adjustment for sociodemographics, waist to hip ratio and conventional cardiovascular risk factors. Inflammation, indexed by plasma interleukin 6 concentration, accounted for 17% of this association. Longitudinally, depressive symptoms did not predict pericardial fat three years later in men once baseline levels of pericardial fat were accounted for. No significant associations between depressive symptoms and pericardial fat were found in women. Overall, our findings suggest that greater pericardial fat might be a mechanism by which depressive symptoms are associated with increased risk for CVD in men, and inflammation may also lie on this pathway.
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Wang L, Ma J, Wu W, Fang Y, Liu F, Yang Q, Hu X, Gu X, He Z, Sun D, Jin L, Zhang X. Effect of aerobic exercise as a treatment on type 2 diabetes mellitus with depression-like behavior zebrafish. Life Sci 2022; 300:120578. [PMID: 35489565 DOI: 10.1016/j.lfs.2022.120578] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 04/11/2022] [Accepted: 04/20/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Depression is the most known complication of type 2 diabetes mellitus (T2DM). Aerobic exercise improves glycemic control in T2DM, although the underlying mechanisms of comorbid depression-like behaviors in T2DM have not yet been fully elucidated. METHODS 120 zebrafish were randomly assigned to four groups: Control, T2DM, T2DM + metformin, and T2DM + aerobic exercise. Then, all animals except the control group were fed with high glucose fairy shrimp (~40 g/kg/day) and exposed reserpine (40 μg/ml for 20 min) for 10 days. Here, behavioral tests were used for model verification. Following the verification, all groups were treated as before. Additionally, the T2DM + metformin group received metformin (~10.6 mg/kg/day) at the same time, while the T2DM + aerobic exercise group received aerobic exercise 30 min/day. Finally, blood glucose and behavioral tests, as well as protein and molecular levels were determined at Day 11 and 12. RESULTS Aerobic exercise alleviated depressive-like behavior and enhanced the levels of antidepressant biomarkers (NE, 5-HIAA) in zebrafish after 10 consecutive days of exercise. Additionally, 10 consecutive days of aerobic exercise decreased the levels of inflammatory biomarkers (IFN-γ, IL-1, IL-4) and depressive biomarkers (cortisol). Meanwhile, it also aided in the reduction of CD11b, IL-6, IL-6R, and caspase-3 expression to combat the neuroinflammation induced by T2DM, mediated the BDNF-TrkB pathway, and increased Bcl-2/Bax levels. CONCLUSION Given the remarkable similarity in neurochemistry between humans and zebrafish, this study supports the effectiveness of aerobic exercise as clinical guidance in preventing and treating T2DM complicated with depression.
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Affiliation(s)
- Lei Wang
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou 325035, China
| | - Jiahui Ma
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou 325035, China
| | - Wei Wu
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing 400044, China
| | - Yimeng Fang
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou 325035, China
| | - Fan Liu
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou 325035, China
| | - Qinsi Yang
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, China
| | - Xiang Hu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China
| | - Xuejiang Gu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China
| | - Zhiying He
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China
| | - Da Sun
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou 325035, China.
| | - Libo Jin
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou 325035, China.
| | - Xingxing Zhang
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China.
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Wojciech K, Zuzanna R, Piotr S, Anna C, Marzena R, Joanna C, Krzysztof J, Zuzanna S. Ketogenic diet impairs neurological development of neonatal rats and affects biochemical composition of maternal brains: evidence of functional recovery in pups. Brain Struct Funct 2022; 227:1099-1113. [PMID: 35038032 PMCID: PMC8930886 DOI: 10.1007/s00429-021-02450-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 12/29/2021] [Indexed: 12/12/2022]
Abstract
The ketogenic diet (KD) is a type of diet in which the intake of fats significantly increases at the cost of carbohydrates while maintaining an adequate amount of proteins. This kind of diet has been successfully used in clinical therapies of drug-resistant epilepsy, but there is still insufficient evidence on its safety when used in pregnancy. To assess KD effects on the course of gestation and fetal development, pregnant females were fed with: (i) KD during pregnancy and lactation periods (KD group), (ii) KD during pregnancy replaced with ND from the day 2 postpartum (KDND group) and (iii) normal diet alone (ND group). The body mass, ketone and glucose blood levels, and food intake were monitored. In brains of KD-fed females, FTIR biochemical analyses revealed increased concentrations of lipids and ketone groups containing molecules. In offspring of these females, significant reduction of the body mass and delays in neurological development were detected. However, replacement of KD with ND in these females at the beginning of lactation period led to regainment of the body mass in their pups as early as on the postnatal day 14. Moreover, the vast majority of our neurological tests detected functional recovery up to the normal level. It could be concluded that the ketogenic diet undoubtedly affects the brain of pregnant females and impairs the somatic and neurological development of their offspring. However, early postnatal withdrawal of this diet may initiate compensatory processes and considerable functional restitution of the nervous system based on still unrecognized mechanisms.
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Affiliation(s)
- Kosiek Wojciech
- Laboratory of Experimental Neuropathology, Institute of Zoology and Biomedical Research, Faculty of Biology, Gronostajowa 9, 30-387, Kraków, Poland
| | - Rauk Zuzanna
- Laboratory of Experimental Neuropathology, Institute of Zoology and Biomedical Research, Faculty of Biology, Gronostajowa 9, 30-387, Kraków, Poland
| | - Szulc Piotr
- Faculty of Biochemistry, Biophysics and Biotechnology, Gronostajowa 7, 30-387, Kraków, Poland
| | - Cichy Anna
- Laboratory of Experimental Neuropathology, Institute of Zoology and Biomedical Research, Faculty of Biology, Gronostajowa 9, 30-387, Kraków, Poland
| | - Rugieł Marzena
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 30-059, Krakow, Poland
| | - Chwiej Joanna
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 30-059, Krakow, Poland
| | - Janeczko Krzysztof
- Laboratory of Experimental Neuropathology, Institute of Zoology and Biomedical Research, Faculty of Biology, Gronostajowa 9, 30-387, Kraków, Poland
| | - Setkowicz Zuzanna
- Laboratory of Experimental Neuropathology, Institute of Zoology and Biomedical Research, Faculty of Biology, Gronostajowa 9, 30-387, Kraków, Poland.
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Suzuki K. Recent Progress in Applicability of Exercise Immunology and Inflammation Research to Sports Nutrition. Nutrients 2021; 13:nu13124299. [PMID: 34959851 PMCID: PMC8709237 DOI: 10.3390/nu13124299] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/03/2021] [Accepted: 11/24/2021] [Indexed: 02/06/2023] Open
Abstract
This article focuses on how nutrition may help prevent and/or assist with recovery from the harmful effects of strenuous acute exercise and physical training (decreased immunity, organ injury, inflammation, oxidative stress, and fatigue), with a focus on nutritional supplements. First, the effects of ketogenic diets on metabolism and inflammation are considered. Second, the effects of various supplements on immune function are discussed, including antioxidant defense modulators (vitamin C, sulforaphane, taheebo), and inflammation reducers (colostrum and hyperimmunized milk). Third, how 3-hydroxy-3-methyl butyrate monohydrate (HMB) may offset muscle damage is reviewed. Fourth and finally, the relationship between exercise, nutrition and COVID-19 infection is briefly mentioned. While additional verification of the safety and efficacy of these supplements is still necessary, current evidence suggests that these supplements have potential applications for health promotion and disease prevention among athletes and more diverse populations.
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Affiliation(s)
- Katsuhiko Suzuki
- Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa 359-1192, Japan
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McKay AKA, Peeling P, Pyne DB, Tee N, Whitfield J, Sharma AP, Heikura IA, Burke LM. Six Days of Low Carbohydrate, Not Energy Availability, Alters the Iron and Immune Response to Exercise in Elite Athletes. Med Sci Sports Exerc 2021; 54:377-387. [PMID: 34690285 DOI: 10.1249/mss.0000000000002819] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To quantify the effects of a short-term (6-day) low carbohydrate (CHO) high fat (LCHF), and low energy availability (LEA) diet on immune, inflammatory, and iron-regulatory responses to exercise in endurance athletes. METHODS Twenty-eight elite male race walkers completed two 6-day diet/training phases. During phase 1 (Baseline), all athletes consumed a high CHO/energy availability (CON) diet (65% CHO and ~ 40 kcal·kg-1 fat free mass (FFM)·day-1). In phase 2 (Adaptation), athletes were allocated to either a CON (n = 10), LCHF (n = 8; <50 g·day-1 CHO and ~ 40 kcal·kg-1 FFM·day-1), or LEA diet (n = 10; 60% CHO and 15 kcal·kg-1 FFM·day-1). At the end of each phase, athletes completed a 25 km race walk protocol at ~75% VO2max. On each occasion, venous blood was collected before and after exercise for interleukin-6, hepcidin, cortisol and glucose concentrations, as well as white blood cell counts. RESULTS The LCHF athletes displayed a greater IL-6 (p = 0.019) and hepcidin (p = 0.011) response to exercise after Adaptation, compared to Baseline. Similarly, post-exercise increases in total white blood cell counts (p = 0.026) and cortisol levels (p < 0.001) were larger compared to Baseline following LCHF Adaptation. Decreases in blood glucose concentrations were evident post-exercise during Adaptation in LCHF (p = 0.049), whereas no change occurred in CON or LEA (p > 0.05). No differences between CON and LEA were evident for any of the measured biological markers (all p > 0.05). CONCLUSION Short-term adherence to a LCHF diet elicited small yet unfavorable iron, immune, and stress responses to exercise. In contrast, no substantial alterations to athlete health were observed when athletes restricted energy availability compared to athletes with adequate energy availability. Therefore, short-term restriction of CHO, rather than energy, may have greater negative impacts on athlete health.
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Affiliation(s)
- Alannah K A McKay
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia Western Australian Institute of Sport, Mt Claremont, WA, Australia School of Human Sciences (Exercise and Sport Science). The University of Western Australia, Crawley, WA, Australia Research Institute for Sport and Exercise, University of Canberra, Canberra, Australia Triathlon Australia, Burleigh Heads, Australia Canadian Sport Institute - Pacific, Victoria, British Columbia, Canada Exercise Science, Physical & Health Education, University of Victoria British Columbia, Canada
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