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Gonçalves AC, Gaspar D, Flores-Félix JD, Falcão A, Alves G, Silva LR. Effects of Functional Phenolics Dietary Supplementation on Athletes' Performance and Recovery: A Review. Int J Mol Sci 2022; 23:4652. [PMID: 35563043 PMCID: PMC9102074 DOI: 10.3390/ijms23094652] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 02/04/2023] Open
Abstract
In recent years, many efforts have been made to identify micronutrients or nutritional strategies capable of preventing, or at least, attenuating, exercise-induced muscle damage and oxidative stress, and improving athlete performance. The reason is that most exercises induce various changes in mitochondria and cellular cytosol that lead to the generation of reactive species and free radicals whose accumulation can be harmful to human health. Among them, supplementation with phenolic compounds seems to be a promising approach since their chemical structure, composed of catechol, pyrogallol, and methoxy groups, gives them remarkable health-promoting properties, such as the ability to suppress inflammatory processes, counteract oxidative damage, boost the immune system, and thus, reduce muscle soreness and accelerate recovery. Phenolic compounds have also already been shown to be effective in improving temporal performance and reducing psychological stress and fatigue. Therefore, the aim of this review is to summarize and discuss the current knowledge on the effects of dietary phenolics on physical performance and recovery in athletes and sports practitioners. Overall, the reports show that phenolics exert important benefits on exercise-induced muscle damage as well as play a biological/physiological role in improving physical performance.
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Affiliation(s)
- Ana C. Gonçalves
- CICS-UBI—Health Sciences Research Centre, University of Beira Interior, 6201-506 Covilhã, Portugal; (A.C.G.); (J.D.F.-F.); (G.A.)
- CIBIT—Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, 3000-548 Coimbra, Portugal;
| | - Dário Gaspar
- Department of Sport Sciences, University of Beira Interior, 6201-001 Covilhã, Portugal;
| | - José David Flores-Félix
- CICS-UBI—Health Sciences Research Centre, University of Beira Interior, 6201-506 Covilhã, Portugal; (A.C.G.); (J.D.F.-F.); (G.A.)
| | - Amílcar Falcão
- CIBIT—Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, 3000-548 Coimbra, Portugal;
- Laboratory of Pharmacology, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Gilberto Alves
- CICS-UBI—Health Sciences Research Centre, University of Beira Interior, 6201-506 Covilhã, Portugal; (A.C.G.); (J.D.F.-F.); (G.A.)
| | - Luís R. Silva
- CICS-UBI—Health Sciences Research Centre, University of Beira Interior, 6201-506 Covilhã, Portugal; (A.C.G.); (J.D.F.-F.); (G.A.)
- CPIRN-UDI/IPG—Center of Potential and Innovation of Natural Resources, Research Unit for Inland Development (UDI), Polytechnic Institute of Guarda, 6300-559 Guarda, Portugal
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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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Rojano-Ortega D. Regular, but not acute, green tea supplementation increases total antioxidant status and reduces exercise-induced oxidative stress: a systematic review. Nutr Res 2021; 94:34-43. [PMID: 34624703 DOI: 10.1016/j.nutres.2021.08.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/20/2021] [Accepted: 08/26/2021] [Indexed: 12/28/2022]
Abstract
This systematic review aims to investigate the effects of green tea supplementation on exercise-induced oxidative stress. Four electronic databases were searched from inception to December 2020: SPORTDiscuss, PubMed, Scopus, and Web of Science. The search strategy was established in the following manner: (green tea) (Title/Abstract) AND (exercise OR training) (Title/Abstract) AND (oxidative stress OR antioxidant OR oxidation) (Title). After the application of inclusion and exclusion criteria 11, randomized or non-randomized control trials were included, 6 with a parallel design and 5 with a crossover design. Study methodological quality was assessed with the PEDro scale, and all studies were considered of moderate quality. Overall, acute green tea ingestion does not appear to influence antioxidant status or reduce exercise-induced oxidative stress. In contrast, green tea supplementation before exercise, for periods of more than 1 week, in a dose range of 400 to 800 mg of catechins per day, appears to be efficacious to increase total antioxidant status and protect cells against exercise-induced oxidative stress. Future investigations should focus on beginning green tea supplementation more than 7 days before exercise and completing it 2 or 3 days after while monitoring the change of markers of oxidative stress up to 48-72 h after exercise.
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Affiliation(s)
- Daniel Rojano-Ortega
- Department of Informatics and Sports, Universidad Pablo de Olavide, ES-41013 Sevilla, España.
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Jakus T, Jurdana M, Žiberna L, Pražnikar ZJ. Acute moderate-intensity exercise increases total antioxidant capacity and anti-inflammatory responses in competitive cyclists: The role of adiponectin. EUR J INFLAMM 2021. [DOI: 10.1177/2058739221998890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
High-intensity exercise can elicit acute changes in the biochemical and physiological processes in the body of an athlete, including increased oxidative stress and inflammation. The purpose of this study was to explore the effect of acute moderate-intensity exercise on total antioxidant capacity (TAC) and serum levels of anti-inflammatory adiponectin (APN), and inflammatory markers in competitive cyclists. Ten male cyclists (age 15–26 years, body mass index 19.4–24.7 kg/m2) participated in this study. Each subject performed the maximal oxygen uptake test (VO2peak) and completed a 10-min cycling exercise at a workload of 50% of the peak of VO2peak. Blood samples were collected on three different occasions: after an overnight fasting and at the exercise workloads of 50% and 100% VO2peak. We measured APN, TAC, inflammatory markers as well as assessed nutrient and energy intake for each participant. Baseline concentration of serum APN (10.92 µg/mL) significantly increased at 50% and at 100% VO2peak. In addition, TAC also increased after acute exercise (0.079 vs 0.093 nmol/µL). The concentration of APN at 50% VO2peak positively correlated with the CRP ( r = 0.640, p = 0.046) and negatively correlated with TNF-α ( r = −0.696, p = 0.025). This test showed that short (10 min) and medium-intensity (50% VO2peak) exercise activity in trained athletes evoked beneficial antioxidant and anti-inflammatory responses. Importantly, this response correlates with the increase in APN levels thereby showing that highly trained individuals have beneficial responses originating from adipose tissue. Our observations show that a short training at moderate activity can be an important preservative strategy during the recovery training period.
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Affiliation(s)
- Tadeja Jakus
- University of Primorska, Faculty of Health Sciences, Izola, Slovenia
| | - Mihaela Jurdana
- University of Primorska, Faculty of Health Sciences, Izola, Slovenia
| | - Lovro Žiberna
- University of Ljubljana, Faculty of Medicine, Institute of Pharmacology and Experimental Toxicology, Ljubljana, Slovenia
| | - Zala J Pražnikar
- University of Primorska, Faculty of Health Sciences, Izola, Slovenia
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Suzuki K, Tominaga T, Ruhee RT, Ma S. Characterization and Modulation of Systemic Inflammatory Response to Exhaustive Exercise in Relation to Oxidative Stress. Antioxidants (Basel) 2020; 9:antiox9050401. [PMID: 32397304 PMCID: PMC7278761 DOI: 10.3390/antiox9050401] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/30/2020] [Accepted: 05/06/2020] [Indexed: 12/11/2022] Open
Abstract
Exhaustive exercise induces systemic inflammatory responses, which are associated with exercise-induced tissue/organ damage, but the sources and triggers are not fully understood. Herein, the basics of inflammatory mediator cytokines and research findings on the effects of exercise on systemic inflammation are introduced. Subsequently, the association between inflammatory responses and tissue damage is examined in exercised and overloaded skeletal muscle and other internal organs. Furthermore, an overview of the interactions between oxidative stress and inflammatory mediator cytokines is provided. Particularly, the transcriptional regulation of redox signaling and pro-inflammatory cytokines is described, as the activation of the master regulatory factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is involved directly or indirectly in controlling pro-inflammatory genes and antioxidant enzymes expression, whilst nuclear factor-kappa B (NF-κB) regulates the pro-inflammatory gene expression. Additionally, preventive countermeasures against the pathogenesis along with the possibility of interventions such as direct and indirect antioxidants and anti-inflammatory agents are described. The aim of this review is to give an overview of studies on the systematic inflammatory responses to exercise, including our own group as well as others. Moreover, the challenges and future directions in understanding the role of exercise and functional foods in relation to inflammation and oxidative stress are discussed.
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Affiliation(s)
- Katsuhiko Suzuki
- Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa 359-1192, Japan
- Correspondence: (K.S.); (S.M.); Tel.: +81-4-2947-6898 (K.S.); +81-4-2947-6753 (S.M.)
| | - Takaki Tominaga
- Graduate School of Sport Sciences, Waseda University, Tokorozawa 359-1192, Japan; (T.T.); (R.T.R.)
| | - Ruheea Taskin Ruhee
- Graduate School of Sport Sciences, Waseda University, Tokorozawa 359-1192, Japan; (T.T.); (R.T.R.)
| | - Sihui Ma
- Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa 359-1192, Japan
- Correspondence: (K.S.); (S.M.); Tel.: +81-4-2947-6898 (K.S.); +81-4-2947-6753 (S.M.)
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Tang GY, Meng X, Gan RY, Zhao CN, Liu Q, Feng YB, Li S, Wei XL, Atanasov AG, Corke H, Li HB. Health Functions and Related Molecular Mechanisms of Tea Components: An Update Review. Int J Mol Sci 2019; 20:E6196. [PMID: 31817990 PMCID: PMC6941079 DOI: 10.3390/ijms20246196] [Citation(s) in RCA: 160] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/02/2019] [Accepted: 12/06/2019] [Indexed: 02/07/2023] Open
Abstract
Tea is widely consumed all over the world. Generally, tea is divided into six categories: White, green, yellow, oolong, black, and dark teas, based on the fermentation degree. Tea contains abundant phytochemicals, such as polyphenols, pigments, polysaccharides, alkaloids, free amino acids, and saponins. However, the bioavailability of tea phytochemicals is relatively low. Thus, some novel technologies like nanotechnology have been developed to improve the bioavailability of tea bioactive components and consequently enhance the bioactivity. So far, many studies have demonstrated that tea shows various health functions, such as antioxidant, anti-inflammatory, immuno-regulatory, anticancer, cardiovascular-protective, anti-diabetic, anti-obesity, and hepato-protective effects. Moreover, it is also considered that drinking tea is safe to humans, since reports about the severe adverse effects of tea consumption are rare. In order to provide a better understanding of tea and its health potential, this review summarizes and discusses recent literature on the bioactive components, bioavailability, health functions, and safety issues of tea, with special attention paid to the related molecular mechanisms of tea health functions.
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Affiliation(s)
- Guo-Yi Tang
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou 510080, China; (G.-Y.T.); (X.M.); (C.-N.Z.); (Q.L.)
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, No. 10 Sassoon Road, Pokfulam, Hong Kong 999077, China; (Y.-B.F.); (S.L.)
| | - Xiao Meng
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou 510080, China; (G.-Y.T.); (X.M.); (C.-N.Z.); (Q.L.)
| | - Ren-You Gan
- Department of Food Science & Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; (X.-L.W.); (H.C.)
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China
| | - Cai-Ning Zhao
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou 510080, China; (G.-Y.T.); (X.M.); (C.-N.Z.); (Q.L.)
| | - Qing Liu
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou 510080, China; (G.-Y.T.); (X.M.); (C.-N.Z.); (Q.L.)
| | - Yi-Bin Feng
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, No. 10 Sassoon Road, Pokfulam, Hong Kong 999077, China; (Y.-B.F.); (S.L.)
| | - Sha Li
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, No. 10 Sassoon Road, Pokfulam, Hong Kong 999077, China; (Y.-B.F.); (S.L.)
| | - Xin-Lin Wei
- Department of Food Science & Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; (X.-L.W.); (H.C.)
| | - Atanas G. Atanasov
- The Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzębiec, 05-552 Magdalenka, Poland;
| | - Harold Corke
- Department of Food Science & Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; (X.-L.W.); (H.C.)
| | - Hua-Bin Li
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou 510080, China; (G.-Y.T.); (X.M.); (C.-N.Z.); (Q.L.)
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Chronic Inflammation as an Immunological Abnormality and Effectiveness of Exercise. Biomolecules 2019; 9:biom9060223. [PMID: 31181700 PMCID: PMC6628010 DOI: 10.3390/biom9060223] [Citation(s) in RCA: 146] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 05/29/2019] [Accepted: 06/03/2019] [Indexed: 12/12/2022] Open
Abstract
Reduced levels of physical activity in people’s daily lives cause the development of metabolic syndromes or age-related disorders. Chronic inflammation is now understood to be an underlying pathological condition in which inflammatory cells such as neutrophils and monocyte/macrophages infiltrate into fat and other tissues and accumulate when people become obese due to overeating and/or physical inactivity. Pro-inflammatory mediators such as cytokines that are secreted in excess from inflammatory cells will not only lead to the development of arteriosclerosis when they chronically affect blood vessels but also bring tissue degeneration and/or dysfunction to various organs. Chronic inflammation is also involved in sarcopenia that brings hypofunction in the elderly, dementia, osteoporosis, or cancer and negatively affects many chronic diseases and people’s healthy life expectancy. In this paper, outlines of such studies are introduced in terms of homeostatic inflammation, which occurs chronically due to the innate immune system and its abnormalities, while focusing on the efficacy of exercise from aspects of immunology and oxidative stress. The preventative effects of functional food ingredients in combination with exercise are also introduced and described. The challenges and future directions in understanding the role of exercise in the control of chronic inflammation are discussed.
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Maiti S, Nazmeen A, Medda N, Patra R, Ghosh TK. Flavonoids green tea against oxidant stress and inflammation with related human diseases. CLINICAL NUTRITION EXPERIMENTAL 2019. [DOI: 10.1016/j.yclnex.2018.12.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Yfanti C, Deli CK, Georgakouli K, Fatouros I, Jamurtas AZ. Sport nutrition, redox homeostasis and toxicity in sport performance. CURRENT OPINION IN TOXICOLOGY 2019. [DOI: 10.1016/j.cotox.2019.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Abstract
Strenuous exercise induces such inflammatory responses as leukocytosis (neutrophilia) and symptoms as delayed-onset muscle soreness and swelling. However, the association between inflammatory mediator cytokines and oxidative stress is not fully delineated. Herein, in addition to basic background information on cytokines, research findings on exertional effects on cytokine release and the underlying mechanisms and triggers are introduced. Then, the associations among cytokine responses, oxidative stress, and tissue damage are described not only in overloaded skeletal muscle, but also in other internal organs. Furthermore, we introduce preventive countermeasures against the exhaustive exercise-induced pathogenesis together with the possibility of antioxidant interventions.
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Ranchordas MK, Rogerson D, Soltani H, Costello JT. Antioxidants for preventing and reducing muscle soreness after exercise. Cochrane Database Syst Rev 2017; 12:CD009789. [PMID: 29238948 PMCID: PMC6486214 DOI: 10.1002/14651858.cd009789.pub2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Muscle soreness typically occurs after intense exercise, unaccustomed exercise or actions that involve eccentric contractions where the muscle lengthens while under tension. It peaks between 24 and 72 hours after the initial bout of exercise. Many people take antioxidant supplements or antioxidant-enriched foods before and after exercise in the belief that these will prevent or reduce muscle soreness after exercise. OBJECTIVES To assess the effects (benefits and harms) of antioxidant supplements and antioxidant-enriched foods for preventing and reducing the severity and duration of delayed onset muscle soreness following exercise. SEARCH METHODS We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, SPORTDiscus, trial registers, reference lists of articles and conference proceedings up to February 2017. SELECTION CRITERIA We included randomised and quasi-randomised controlled trials investigating the effects of all forms of antioxidant supplementation including specific antioxidant supplements (e.g. tablets, powders, concentrates) and antioxidant-enriched foods or diets on preventing or reducing delayed onset muscle soreness (DOMS). We excluded studies where antioxidant supplementation was combined with another supplement. DATA COLLECTION AND ANALYSIS Two review authors independently screened search results, assessed risk of bias and extracted data from included trials using a pre-piloted form. Where appropriate, we pooled results of comparable trials, generally using the random-effects model. The outcomes selected for presentation in the 'Summary of findings' table were muscle soreness, collected at times up to 6 hours, 24, 48, 72 and 96 hours post-exercise, subjective recovery and adverse effects. We assessed the quality of the evidence using GRADE. MAIN RESULTS Fifty randomised, placebo-controlled trials were included, 12 of which used a cross-over design. Of the 1089 participants, 961 (88.2%) were male and 128 (11.8%) were female. The age range for participants was between 16 and 55 years and training status varied from sedentary to moderately trained. The trials were heterogeneous, including the timing (pre-exercise or post-exercise), frequency, dose, duration and type of antioxidant supplementation, and the type of preceding exercise. All studies used an antioxidant dosage higher than the recommended daily amount. The majority of trials (47) had design features that carried a high risk of bias due to selective reporting and poorly described allocation concealment, potentially limiting the reliability of their findings.We tested only one comparison: antioxidant supplements versus control (placebo). No studies compared high-dose versus low-dose, where the low-dose supplementation was within normal or recommended levels for the antioxidant involved.Pooled results for muscle soreness indicated a small difference in favour of antioxidant supplementation after DOMS-inducing exercise at all main follow-ups: up to 6 hours (standardised mean difference (SMD) -0.30, 95% confidence interval (CI) -0.56 to -0.04; 525 participants, 21 studies; low-quality evidence); at 24 hours (SMD -0.13, 95% CI -0.27 to 0.00; 936 participants, 41 studies; moderate-quality evidence); at 48 hours (SMD -0.24, 95% CI -0.42 to -0.07; 1047 participants, 45 studies; low-quality evidence); at 72 hours (SMD -0.19, 95% CI -0.38 to -0.00; 657 participants, 28 studies; moderate-quality evidence), and little difference at 96 hours (SMD -0.05, 95% CI -0.29 to 0.19; 436 participants, 17 studies; low-quality evidence). When we rescaled to a 0 to 10 cm scale in order to quantify the actual difference between groups, we found that the 95% CIs for all five follow-up times were all well below the minimal important difference of 1.4 cm: up to 6 hours (MD -0.52, 95% CI -0.95 to -0.08); at 24 hours (MD -0.17, 95% CI -0.42 to 0.07); at 48 hours (MD -0.41, 95% CI -0.69 to -0.12); at 72 hours (MD -0.29, 95% CI -0.59 to 0.02); and at 96 hours (MD -0.03, 95% CI -0.43 to 0.37). Thus, the effect sizes suggesting less muscle soreness with antioxidant supplementation were very unlikely to equate to meaningful or important differences in practice. Neither of our subgroup analyses to examine for differences in effect according to type of DOMS-inducing exercise (mechanical versus whole body aerobic) or according to funding source confirmed subgroup differences. Sensitivity analyses excluding cross-over trials showed that their inclusion had no important impact on results.None of the 50 included trials measured subjective recovery (return to previous activities without signs or symptoms).There is very little evidence regarding the potential adverse effects of taking antioxidant supplements as this outcome was reported in only nine trials (216 participants). From the studies that did report adverse effects, two of the nine trials found adverse effects. All six participants in the antioxidant group of one trial had diarrhoea and four of these also had mild indigestion; these are well-known side effects of the particular antioxidant used in this trial. One of 26 participants in a second trial had mild gastrointestinal distress. AUTHORS' CONCLUSIONS There is moderate to low-quality evidence that high dose antioxidant supplementation does not result in a clinically relevant reduction of muscle soreness after exercise at up to 6 hours or at 24, 48, 72 and 96 hours after exercise. There is no evidence available on subjective recovery and only limited evidence on the adverse effects of taking antioxidant supplements. The findings of, and messages from, this review provide an opportunity for researchers and other stakeholders to come together and consider what are the priorities, and underlying justifications, for future research in this area.
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Affiliation(s)
- Mayur K Ranchordas
- Sheffield Hallam UniversityDepartment of SportCollegiate Crescent CampusA221 Collegiate Hall, Ecclesall RoadSheffieldSouth YorkshireUKS10 2BP
| | - David Rogerson
- Sheffield Hallam UniversityDepartment of SportCollegiate Crescent CampusA221 Collegiate Hall, Ecclesall RoadSheffieldSouth YorkshireUKS10 2BP
| | - Hora Soltani
- Sheffield Hallam UniversityCentre for Health and Social Care Research32 Collegiate CrescentSheffieldUKS10 2BP
| | - Joseph T Costello
- University of PortsmouthDepartment of Sport and Exercise ScienceSpinnaker BuildingCambridge RoadPortsmouthUKP01 2ER
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Haghighatdoost F, Nobakht M Gh BF, Hariri M. Effect of Green Tea on Plasma Adiponectin Levels: A Systematic Review and Meta-analysis of Randomized Controlled Clinical Trials. J Am Coll Nutr 2017; 36:541-548. [PMID: 28853999 DOI: 10.1080/07315724.2017.1333470] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Our objective was to perform a systematic review and meta-analysis on randomized controlled trials (RCTs) assessing the effect of green tea on serum adiponectin concentration. METHOD We searched PubMed, ISI Web of Science, Scopus, and the Google Scholar databases up to November 2016. RCTs conducted among human adults studied the effects of green tea and green tea extract on serum adiponectin concentrations as an outcome variable was included. The weighted mean differences and standard deviations (SD) of change in serum adiponectin levels were calculated. The random effects model was used for deriving a summary of mean estimates with their corresponding SDs. The protocol was registered with PROSPERO (No. CRD42017057716). RESULT Fourteen RCTs were eligible to be included in the systematic review and the meta-analysis. Our analysis showed that green tea did not significantly affect adiponectin concentrations in comparison with placebo (weighted mean difference = -0.02 µg/ml, 95% confidence interval [CI], -0.41, 0.38; p = 0.936). There was a substantial heterogeneity between studies (I2 = 91.7%; p < 0.0001). Subgroup analyses based on sex, type of intervention, continent, and body mass index (BMI) could not explain the sources of heterogeneity. Metaregression analyses revealed that the dose and duration of green tea ingestion did not have any effect on adiponectin concentrations. CONCLUSION Green tea could not change the circulatory adiponectin levels. The dose and duration of green tea could not change the result. RCTs with longer follow-up periods and higher doses are needed to replicate our results.
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Affiliation(s)
- Fahimeh Haghighatdoost
- a Food Security Research Center , Isfahan University of Medical Sciences , Isfahan , Iran.,b Department of Community Nutrition, School of Nutrition and Food Science , Isfahan University of Medical Sciences , Isfahan , Iran
| | - B Fatemeh Nobakht M Gh
- c Department of Basic Medical Sciences , Neyshabur University of Medical Sciences , Neyshabur , Iran
| | - Mitra Hariri
- c Department of Basic Medical Sciences , Neyshabur University of Medical Sciences , Neyshabur , Iran
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