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British Journal of Sports Medicine Mar 2018We performed a systematic review, meta-analysis and meta-regression to determine if dietary protein supplementation augments resistance exercise training (RET)-induced... (Meta-Analysis)
Meta-Analysis Review
A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults.
OBJECTIVE
We performed a systematic review, meta-analysis and meta-regression to determine if dietary protein supplementation augments resistance exercise training (RET)-induced gains in muscle mass and strength.
DATA SOURCES
A systematic search of Medline, Embase, CINAHL and SportDiscus.
ELIGIBILITY CRITERIA
Only randomised controlled trials with RET ≥6 weeks in duration and dietary protein supplementation.
DESIGN
Random-effects meta-analyses and meta-regressions with four a priori determined covariates. Two-phase break point analysis was used to determine the relationship between total protein intake and changes in fat-free mass (FFM).
RESULTS
Data from 49 studies with 1863 participants showed that dietary protein supplementation significantly (all p<0.05) increased changes (means (95% CI)) in: strength-one-repetition-maximum (2.49 kg (0.64, 4.33)), FFM (0.30 kg (0.09, 0.52)) and muscle size-muscle fibre cross-sectional area (CSA; 310 µm (51, 570)) and mid-femur CSA (7.2 mm (0.20, 14.30)) during periods of prolonged RET. The impact of protein supplementation on gains in FFM was reduced with increasing age (-0.01 kg (-0.02,-0.00), p=0.002) and was more effective in resistance-trained individuals (0.75 kg (0.09, 1.40), p=0.03). Protein supplementation beyond total protein intakes of 1.62 g/kg/day resulted in no further RET-induced gains in FFM.
SUMMARY/CONCLUSION
Dietary protein supplementation significantly enhanced changes in muscle strength and size during prolonged RET in healthy adults. Increasing age reduces and training experience increases the efficacy of protein supplementation during RET. With protein supplementation, protein intakes at amounts greater than ~1.6 g/kg/day do not further contribute RET-induced gains in FFM.
Topics: Adult; Dietary Proteins; Dietary Supplements; Humans; Muscle Strength; Muscle, Skeletal; Randomized Controlled Trials as Topic; Regression Analysis; Resistance Training
PubMed: 28698222
DOI: 10.1136/bjsports-2017-097608 -
British Journal of Clinical Pharmacology Feb 2021To present an updated overview on the safety of concurrent use of food, herbal or dietary supplement and warfarin. (Review)
Review
AIMS
To present an updated overview on the safety of concurrent use of food, herbal or dietary supplement and warfarin.
METHODS
A systematic literature review was performed on 5 databases from inception up to 31 December 2019. These interactions were classified depending on the likelihood of interaction and supporting evidences.
RESULTS
A total of 149 articles describing 78 herbs, food or dietary supplements were reported to interact with warfarin. These reports described potentiation with 45 (57.7%) herbs, food or dietary supplements while 23 (29.5%) reported inhibition and 10 (12.8%) reported limited impact on warfarin pharmacokinetics and pharmacodynamics. Twenty unique herb and dietary supplements also reported to result in minor bleeding events, such as purpura and gum bleeding as well as major events such as intracranial bleeding that led to death.
CONCLUSION
While most food, herbs and supplements can be safely taken in moderation, healthcare professionals should be aware of the increased risk of bleeding when taking several food and herbs. These include Chinese wolfberry, chamomile tea, cannabis, cranberry, chitosan, green tea, Ginkgo biloba, ginger, spinach, St. John's Wort, sushi and smoking tobacco. Patients should be counselled to continue to seek advice from their healthcare professionals when starting any new herbs, food or supplement.
Topics: Dietary Supplements; Ginkgo biloba; Herb-Drug Interactions; Humans; Phytotherapy; Warfarin
PubMed: 32478963
DOI: 10.1111/bcp.14404 -
Nutrients Nov 2022Immune health products represent approximately 10% of all US dietary supplement sales. Claims made on products to support or boost the immune system are attractive to... (Review)
Review
Immune health products represent approximately 10% of all US dietary supplement sales. Claims made on products to support or boost the immune system are attractive to the otherwise healthy consumer who may or may not be experiencing certain life stressors. The purpose of this systematic review is to critically evaluate the purported benefits and/or potential harms of select dietary supplement ingredients frequently listed on the labels of products having immune health or related market claims. With a focus on resilience, research questions were related to whether dietary supplement ingredients are efficacious in preserving and protecting immune health in healthy individuals; and when faced with a stressor, whether taking a supplement prophylactically can assist in maintaining health and resisting or bouncing back more quickly. Thirty-nine randomized controlled studies involving populations including children, adults and seniors exposed to stressors, such as air travel, intense exercise, academic stress, and/or exposure to winter weather, met eligibility criteria. The studies included eight of the 27 supplement ingredients identified through a market-driven scoping review. Those ingredients used in single ingredient products were echinacea, elderberry, garlic, vitamin A, vitamin C, vitamin D, vitamin E, and zinc. Whereas some studies may point to evidence for benefit, specific gaps preclude the authors from making firm statements with regard to the overall evidence-base for these products and ingredients and in answering the research questions. As we move toward a vision of health promotion and resilience rather than a sole focus on disease prevention and treatment, further work in this area of dietary supplements is of utmost importance.
Topics: Adult; Child; Humans; Dietary Supplements; Vitamins; Exercise; Biological Products; Immune System
PubMed: 36364865
DOI: 10.3390/nu14214604 -
Sports Medicine (Auckland, N.Z.) Jan 2016Dietary supplements (DSs) are commercially available products consumed as an addition to the usual diet and are frequently ingested by athletes. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Dietary supplements (DSs) are commercially available products consumed as an addition to the usual diet and are frequently ingested by athletes.
OBJECTIVE
Our objective was to examine the prevalence of DS use by athletes.
DATA SOURCES
PubMed, Ovid MEDLINE, OVID Healthstar, and Cumulative Index to Nursing and Allied Health were searched for original research articles published up to August 2014. Search terms included specific sports, specific DSs, and other terms.
STUDY SELECTION
Studies were selected if they were written in English, involved athletes, and provided a quantitative assessment of the proportion of athletes using specific DSs. Percent of athletes using specific DSs.
SYNTHESIS OF DATA
Methodological quality of studies was assessed by three reviewers using an 8-point scale that included evaluations for sampling methods, sampling frame, sample size, measurement tools, bias, response rate, statistical presentation, and description of the participant sample. Where there were at least two investigations, meta-analysis was performed to obtain summary (pooled) prevalence estimates (SPEs) on (1) DS use prevalence by sport and sex, (2) DS use prevalence by elite versus non-elite athletic status, and (3) specific DS prevalence for all athletic groups combined. Meta-analyses included evaluations of homogeneity and publication bias.
RESULTS
A total of 159 unique studies met the review criteria. Methodological quality was generally low with an average ± standard deviation of 43 ± 16% of available rating points. There was low homogeneity for SPEs when compiled by sport, athletic status, and/or specific DSs. Contributing to the lack of homogeneity were differences in studies' objectives and types of assessments used (e.g., dietary surveys, interviews, questionnaires). Despite these limitations, the data generally indicated that elite athletes used DSs much more than their non-elite counterparts. For most DSs, use prevalence was similar for men and women except that a larger proportion of women used iron while a larger proportion of men used vitamin E, protein, and creatine. No consistent change in use over time was observed because even the earliest investigations showed relatively high use prevalence.
CONCLUSION
It was difficult to generalize regarding DS use by athletes because of the lack of homogeneity among studies. Nonetheless, the data suggested that elite athletes used dietary supplements far more than their non-elite counterparts; use was similar for men and women with a few exceptions; use appeared to change little over time; and a larger proportion of athletes used DSs compared with the general US population. Improvements in study methodology should be considered in future studies especially (1) defining DSs for participants; (2) querying for very specific DSs; (3) using a variety of reporting timeframes (e.g., daily, 2-6 times/week, 1 time/week and <1 time/week); (4) reporting the sampling frame, number of individuals solicited, and number responding; (5) reporting characteristics of volunteers (and non-volunteers, if available); and (6) using similar methods on several occasions to examine possible temporal trends among athletes.
Topics: Athletes; Creatine; Dietary Proteins; Dietary Supplements; Humans; Iron, Dietary; Sex Factors; Vitamin E
PubMed: 26442916
DOI: 10.1007/s40279-015-0387-7 -
Applied Physiology, Nutrition, and... Jan 2021Whey protein comprises soluble whey proteins and its benefits are well described in the literature. However, there are not many studies investigating the potential...
Whey protein comprises soluble whey proteins and its benefits are well described in the literature. However, there are not many studies investigating the potential adverse effect of a diet with indiscriminate use of this supplement. The aim of this study was to perform a systematic review of papers that addressed this theme. A search was conducted in Medline, LILACS, TOXNET, Web of science, and Scopus electronic databases. In the end, 11 documents comprised this review. The majority of the papers associated the damaging effect with the chronic and abusive use of whey protein, with the kidneys and liver being the main organs affected. The other studies related whey protein to aggravation of aggression, presence of acne, and modification of the microbiota. Therefore, excessive consumption over a long period of protein supplementation may have some adverse effects on the body, which is aggravated when associated with sedentary lifestyle. PROSPERO registration no.: CRD42020140466. A systematic review of experimental and randomized studies about the use of whey proteins supplements and its impact on physical health. Analysis revealed that chronic and without professional guidance use of whey protein supplementation may cause some adverse effects specially on kidney and liver function. Presented data support a need for future studies co-relating the use of different types of whey protein with and without exercise to better see the impact on human physical health.
Topics: Diet; Dietary Supplements; Gastrointestinal Microbiome; Health Status; Humans; Kidney Diseases; Liver Diseases; Whey Proteins
PubMed: 32702243
DOI: 10.1139/apnm-2020-0370 -
Obesity (Silver Spring, Md.) Jul 2021Dietary supplements and alternative therapies are commercialized as a panacea for obesity/weight gain as a result of the minimal regulatory requirements in demonstrating... (Review)
Review
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.
Topics: Adolescent; Adult; Complementary Therapies; Dietary Supplements; Humans; Obesity; Weight Loss
PubMed: 34159755
DOI: 10.1002/oby.23110 -
Postgraduate Medical Journal Apr 2022Different dietary supplements aimed at improving sleep quality are available on the market, but there has not been a comprehensive review to evaluate the efficacy of... (Meta-Analysis)
Meta-Analysis
PURPOSE
Different dietary supplements aimed at improving sleep quality are available on the market, but there has not been a comprehensive review to evaluate the efficacy of these dietary supplements on subjective sleep quality. We aimed to summarise up-to-date research evidence and to identify the types of dietary supplement that improve subjective sleep quality.
METHODS
Multiple databases (Ovid Emcare, Ovid MEDLINE (R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations and APA PsycInfo) were used for searching papers published until August 2020. The changes in sleep quality indices, intervention duration and sample size were extracted from every paper. To analyse the effect of dietary supplements on sleep quality, a random effects model with mean difference (MD) and 95% CI was adopted. The heterogeneity across studies was measured by I statistics. The quality of included studies was evaluated by Cochrane's risk of bias tool.
RESULTS
Thirty-one randomised controlled trials of dietary supplements were included. Subjective sleep quality was significantly improved by supplementation of amino acids (MD -1.27, 95% CI -2.35 to -0.20; I=0%), melatonin (MD -1.21, 95% CI -2.17 to -0.24; I=79%) and vitamin D (MD -1.63, 95% CI -3.15 to -0.10; I=85%). Although not all studies provided adequate data for meta-analysis, we also discussed how magnesium, zinc, resveratrol and nitrate supplementation may improve sleep quality.
CONCLUSIONS
Amino acids, vitamin D and melatonin supplements were significantly beneficial to improve sleep quality. However, high heterogeneity and wide confidence levels were observed in vitamin D and melatonin. Further research on the effect of magnesium, zinc, resveratrol and nitrate supplementation on improving sleep quality is required.
Topics: Dietary Supplements; Humans; Sleep Quality; Vitamins
PubMed: 33441476
DOI: 10.1136/postgradmedj-2020-139319 -
Nutrition Reviews Mar 2021The impact of various dietary interventions on rheumatoid arthritis (RA), characterized by immune-inflammatory response, has been subject to increased attention.
CONTEXT
The impact of various dietary interventions on rheumatoid arthritis (RA), characterized by immune-inflammatory response, has been subject to increased attention.
OBJECTIVE
A systematic review was conducted to update the current knowledge on the effects of nutritional, dietary supplement, and fasting interventions on RA outcomes.
DATA SOURCES
Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, with prespecification of all methods, Medline and Embase were systematically searched for relevant articles.
DATA EXTRACTION
Data were extracted by 2 independent reviewers.
RESULTS
A total of 70 human studies were identified. Administration of omega-3 polyunsaturated fatty acids at high doses resulted in a reduction in RA disease activity and a lower failure rate of pharmacotherapy. Vitamin D supplementation and dietary sodium restriction were beneficial on some RA outcomes. Fasting resulted in significant but transient subjective improvements. While the Mediterranean diet demonstrated improvements in some RA disease activity measures, outcomes from vegetarian, elimination, peptide, or elemental diets suggested that responses are very individualized.
CONCLUSION
Some dietary approaches may improve RA symptoms and thus it is recommended that nutrition should be routinely addressed.
Topics: Arthritis, Rheumatoid; Clinical Trials as Topic; Dietary Supplements; Humans
PubMed: 32585000
DOI: 10.1093/nutrit/nuaa033 -
International Journal of Sport... Mar 2021CrossFit® is a high-intensity functional training method consisting of daily workouts called "workouts of the day." No nutritional recommendations exist for CrossFit®...
CrossFit® is a high-intensity functional training method consisting of daily workouts called "workouts of the day." No nutritional recommendations exist for CrossFit® that are supported by scientific evidence regarding the energetic demands of this type of activity or dietary and supplement interventions. This systematic review performed in accordance with PRISMA guidelines aimed to identify studies that determined (a) the physiological and metabolic demands of CrossFit® and (b) the effects of nutritional strategies on CrossFit® performance to guide nutritional recommendations for optimal recovery, adaptations, and performance for CrossFit® athletes and direct future research in this emerging area. Three databases were searched for studies that investigated physiological responses to CrossFit® and dietary or supplementation interventions on CrossFit® performance. Various physiological measures revealed the intense nature of all CrossFit® workouts of the day, reflected in substantial muscle fatigue and damage. Dietary and supplementation studies provided an unclear insight into effective strategies to improve performance and enhance adaptations and recovery due to methodological shortcomings across studies. This systematic review showed that CrossFit® is a high-intensity sport with fairly homogenous anaerobic and aerobic characteristics, resulting in substantial metabolic stress, leading to metabolite accumulation (e.g., lactate and hydrogen ions) and increased markers of muscle damage and muscle fatigue. Limited interventional data exist on dietary and supplementation strategies to optimize CrossFit® performance, and most are moderate to very low quality with some critical methodological limitations, precluding solid conclusions on their efficacy. High-quality work is needed to confirm the ideal dietary and supplemental strategies for optimal performance and recovery for CrossFit® athletes and is an exciting avenue for further research.
Topics: Athletic Performance; Biomedical Research; Diet; Dietary Supplements; Energy Metabolism; Forecasting; Heart Rate; Humans; Lactic Acid; Muscle Fatigue; Myalgia; Oxygen Consumption; Physical Conditioning, Human
PubMed: 33513565
DOI: 10.1123/ijsnem.2020-0223 -
Journal of the International Society of... 2022Tendinopathy is a painful condition that is prevalent in athletes as well as the general human population, and whose management is challenging. (Review)
Review
BACKGROUND
Tendinopathy is a painful condition that is prevalent in athletes as well as the general human population, and whose management is challenging.
OBJECTIVE
This systematic review aimed to evaluate the impact of nutrition on the prevention and treatment of tendinopathy.
METHODS
Searches were conducted in PubMed, EMBASE, Web of Science, and SPORTDiscus without restriction to year of publication. Studies examining the impact of exposure to nutrient intake in an adult human population on 1) prevalence/incidence of tendinopathy, 2) clinical outcomes of tendinopathy, 3) structural changes in the tendon by imaging modalities. Experimental and observational study designs written in English, Dutch, or German were eligible.
RESULTS
Nineteen studies met the inclusion criteria. The effects of the habitual diet were investigated in one study. Four studies examined the effects of exposure to alcohol. Alcohol consumption can be a potential risk factor associated with Achilles tendinopathy and rotator cuff tears, although findings were inconsistent. The use of dietary supplements was examined in fourteen studies. Among these, collagen-derived peptides were most often part of the supplements evaluated. Combining training and dietary supplements seems to induce better clinical and functional outcomes in tendinopathy.
CONCLUSION
This review demonstrates the paucity of high-quality studies and a wide variety among studies regarding nutrients, tendon location, study population, and reported outcome measures. Individual studies showed promising clinical implications for the use of dietary supplements, particularly those containing collagen-derived peptides. However, giving any definitive dietary recommendations on the prevention and treatment of tendinopathy remains elusive.
Topics: Achilles Tendon; Adult; Diet; Dietary Supplements; Humans; Nutritional Status; Observational Studies as Topic; Tendinopathy
PubMed: 35937777
DOI: 10.1080/15502783.2022.2104130