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International Journal of Environmental... Apr 2020Creatine monohydrate is a nutritional supplement often consumed by athletes in anaerobic sports. Creatine is naturally found in most meat products; therefore,...
BACKGROUND
Creatine monohydrate is a nutritional supplement often consumed by athletes in anaerobic sports. Creatine is naturally found in most meat products; therefore, vegetarians have reduced creatine stores and may benefit from supplementation.
OBJECTIVE
to determine the effects of creatine supplementation on vegetarians.
DATA SOURCES
PubMed and SPORTDiscus. Eligibility criteria: Randomized controlled trials (parallel group, cross-over studies) or prospective studies.
PARTICIPANTS
Vegetarians.
INTERVENTION
Creatine supplementation. Study appraisal and synthesis: A total of 64 records were identified, and eleven full-text articles (covering nine studies) were included in this systematic review.
RESULTS
Creatine supplementation in vegetarians increased total creatine, creatine, and phosphocreatine concentrations in vastus lateralis and gastrocnemius muscle, plasma, and red blood cells, often to levels greater than omnivores. Creatine supplementation had no effect on brain levels of phosphocreatine. Creatine supplementation increased lean tissue mass, type II fiber area, insulin-like growth factor-1, muscular strength, muscular endurance, Wingate mean power output, and brain function (memory and intelligence) in vegetarian participants. Studies were mixed on whether creatine supplementation improved exercise performance in vegetarians to a greater extent compared to omnivores.
LIMITATIONS
Studies that were reviewed had moderate-high risk of bias.
CONCLUSIONS
Overall, it appears vegetarian athletes are likely to benefit from creatine supplementation.
Topics: Athletes; Cognition; Creatine; Diet, Vegetarian; Dietary Supplements; Humans; Memory; Physical Fitness; Prospective Studies; Vegetarians
PubMed: 32349356
DOI: 10.3390/ijerph17093041 -
The American Journal of Clinical... Oct 2022Chronic constipation is a prevalent disorder that remains challenging to treat. Studies suggest increasing fiber intake may improve symptoms, although recommendations on... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Chronic constipation is a prevalent disorder that remains challenging to treat. Studies suggest increasing fiber intake may improve symptoms, although recommendations on the fiber type, dose, and treatment duration are unclear.
OBJECTIVES
We investigated the effects of fiber supplementation on stool output, gut transit time, symptoms, and quality of life in adults with chronic constipation via a systematic review and meta-analysis of randomized controlled trials (RCTs).
METHODS
Studies were identified using electronic databases, backward citation, and hand searches of abstracts. RCTs reporting administration of fiber supplementation in adults with chronic constipation were included. Risks of bias (RoB) was assessed with the Cochrane RoB 2.0 tool. Results were synthesized using risk ratios (RRs), mean differences, or standardized mean differences (SMDs) and 95% CIs using a random-effects model.
RESULTS
Sixteen RCTs with 1251 participants were included. Overall, 311 of 473 (66%) participants responded to fiber treatment and 134 of 329 (41%) responded to control treatment [RR: 1.48 (95% CI: 1.17, 1.88; P = 0.001); I2 = 57% (P = 0.007)], with psyllium and pectin having significant effects. A higher response to treatment was apparent in fiber groups compared to control groups irrespective of the treatment duration, but only with higher fiber doses (>10 g/d). Fiber increased stool frequency [SMD: 0.72 (95% CI: 0.36, 1.08; P = 0.0001); I2 = 86% (P < 0.00001)]; psyllium and pectin had significant effects, and improvement was apparent only with higher fiber doses and greater treatment durations (≥4 weeks). Fiber improved stool consistency (SMD: 0.32; 95% CI: 0.18, 0.46; P < 0.0001), particularly with higher fiber doses. Flatulence was higher in fiber groups compared to control groups(SMD: 0.80; 95% CI: 0.47, 1.13; P < 0.00001).
CONCLUSIONS
Fiber supplementation is effective at improving constipation. Particularly, psyllium, doses >10 g/d and treatment durations of at least 4 weeks appear optimal, though caution is needed when interpreting the results due to considerable heterogeneity. These findings provide promising evidence on the optimal type and regime of fiber supplementation, which could be used to standardize recommendations to patients. The protocol for this review is registered at PROSPERO as CRD42020191404.
Topics: Adult; Constipation; Dietary Fiber; Dietary Supplements; Humans; Pectins; Psyllium; Randomized Controlled Trials as Topic
PubMed: 35816465
DOI: 10.1093/ajcn/nqac184 -
Nutrients Feb 2023It is estimated that three to five million sports injuries occur worldwide each year. The highest incidence is reported during competition periods with mainly... (Review)
Review
It is estimated that three to five million sports injuries occur worldwide each year. The highest incidence is reported during competition periods with mainly affectation of the musculoskeletal tissue. For appropriate nutritional management and correct use of nutritional supplements, it is important to individualize based on clinical effects and know the adaptive response during the rehabilitation phase after a sports injury in athletes. Therefore, the aim of this PRISMA in Exercise, Rehabilitation, Sport Medicine and Sports Science PERSiST-based systematic integrative review was to perform an update on nutritional strategies during the rehabilitation phase of musculoskeletal injuries in elite athletes. After searching the following databases: PubMed/Medline, Scopus, PEDro, and Google Scholar, a total of 18 studies met the inclusion criteria (Price Index: 66.6%). The risk of bias assessment for randomized controlled trials was performed using the RoB 2.0 tool while review articles were evaluated using the AMSTAR 2.0 items. Based on the main findings of the selected studies, nutritional strategies that benefit the rehabilitation process in injured athletes include balanced energy intake, and a high-protein and carbohydrate-rich diet. Supportive supervision should be provided to avoid low energy availability. The potential of supplementation with collagen, creatine monohydrate, omega-3 (fish oils), and vitamin D requires further research although the effects are quite promising. It is worth noting the lack of clinical research in injured athletes and the higher number of reviews in the last 10 years. After analyzing the current quantitative and non-quantitative evidence, we encourage researchers to conduct further clinical research studies evaluating doses of the discussed nutrients during the rehabilitation process to confirm findings, but also follow international guidelines at the time to review scientific literature.
Topics: Humans; Sports; Athletes; Dietary Supplements; Exercise; Athletic Injuries
PubMed: 36839176
DOI: 10.3390/nu15040819 -
Journal of the International Society of... Sep 2020L-carnitine (LC) is used as a supplement by recreationally-active, competitive and highly trained athletes. This systematic review aims to evaluate the effect of...
BACKGROUND
L-carnitine (LC) is used as a supplement by recreationally-active, competitive and highly trained athletes. This systematic review aims to evaluate the effect of prolonged LC supplementation on metabolism and metabolic modifications.
METHODS
A literature search was conducted in the MEDLINE (via PubMed) and Web of Science databases from the inception up February 2020. Eligibility criteria included studies on healthy human subjects, treated for at least 12 weeks with LC administered orally, with no drugs or any other multi-ingredient supplements co-ingestion.
RESULTS
The initial search retrieved 1024 articles, and a total of 11 studies were finally included after applying inclusion and exclusion criteria. All the selected studies were conducted with healthy human subjects, with supplemented dose ranging from 1 g to 4 g per day for either 12 or 24 weeks. LC supplementation, in combination with carbohydrates (CHO) effectively elevated total carnitine content in skeletal muscle. Twenty-four-weeks of LC supplementation did not affect muscle strength in healthy aged women, but significantly increased muscle mass, improved physical effort tolerance and cognitive function in centenarians. LC supplementation was also noted to induce an increase of fasting plasma trimethylamine-N-oxide (TMAO) levels, which was not associated with modification of determined inflammatory nor oxidative stress markers.
CONCLUSION
Prolonged LC supplementation in specific conditions may affect physical performance. On the other hand, LC supplementation elevates fasting plasma TMAO, compound supposed to be pro-atherogenic. Therefore, additional studies focusing on long-term supplementation and its longitudinal effect on the cardiovascular system are needed.
Topics: Age Factors; Body Composition; Carnitine; Cognition; Dietary Carbohydrates; Dietary Supplements; Energy Metabolism; Exercise; Exercise Tolerance; Humans; Lipid Metabolism; Methylamines; Muscle Proteins; Muscle Strength; Muscle, Skeletal; Obesity; Oxidation-Reduction; Physical Conditioning, Human; Sarcopenia
PubMed: 32958033
DOI: 10.1186/s12970-020-00377-2 -
Nutrition (Burbank, Los Angeles County,... Oct 2022With increasing life expectancy of patients with cystic fibrosis (CF), gastrointestinal manifestations of the disease have been increasingly brought into focus. This was... (Review)
Review
With increasing life expectancy of patients with cystic fibrosis (CF), gastrointestinal manifestations of the disease have been increasingly brought into focus. This was a systematic review of the PubMed database and ongoing phase III clinical trials that aimed to summarize recent (published after June 1 2016) studies reporting the effects of nutritional interventions on anthropometric measures (weight, height, and body mass index) in patients with CF. Two ongoing trials and 40 published studies (18 interventional and 22 observational) were identified. Key results supported the benefits of comprehensive, individualized nutritional plans, high-fat, high-calorie diet including high-quality carbohydrates, and enteric tube feeding (albeit the latter was derived from observational studies only). In contrast, the supplementation of probiotics, lipids, docosahexaenoic, glutathione, or antioxidant-enriched multivitamin appeared to have little effect on anthropometric measures.
Topics: Body Height; Body Mass Index; Cystic Fibrosis; Enteral Nutrition; Humans; Nutritional Status
PubMed: 35816813
DOI: 10.1016/j.nut.2022.111725 -
Journal of Human Kinetics Aug 2019Beta-hydroxy-beta-methylbutyrate (HMB) has been used extensively as a dietary supplement for athletes and physically active people. HMB is a leucine metabolite, which is...
Beta-hydroxy-beta-methylbutyrate (HMB) has been used extensively as a dietary supplement for athletes and physically active people. HMB is a leucine metabolite, which is one of three branched chain amino acids. HMB plays multiple roles in the human body of which most important ones include protein metabolism, insulin activity and skeletal muscle hypertrophy. The ergogenic effects of HMB supplementation are related to the enhancement of sarcolemma integrity, inhibition of protein degradation (ubiquitin pathway), decreased cell apoptosis, increased protein synthesis (mTOR pathway), stimulation of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis and enhancement of muscle stem cells proliferation and differentiation. HMB supplementation has been carried out with various groups of athletes. In endurance and martial arts athletes, HMB supplementation revealed positive effects on specific aerobic capacity variables. Positive results were also disclosed in resistance trained athletes, where changes in strength, body fat and muscle mass as well as anaerobic performance and power output were observed. The purpose of this review was to present the main mechanisms of HMB action, especially related to muscle protein synthesis and degradation, and ergogenic effects on different types of sports and physical activities.
PubMed: 31531146
DOI: 10.2478/hukin-2019-0070 -
The Cochrane Database of Systematic... Jul 2015Iron and folic acid supplementation has been the preferred intervention to improve iron stores and prevent anaemia among pregnant women, and it is thought to improve... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Iron and folic acid supplementation has been the preferred intervention to improve iron stores and prevent anaemia among pregnant women, and it is thought to improve other maternal and birth outcomes.
OBJECTIVES
To assess the effects of daily oral iron supplements for pregnant women, either alone or in conjunction with folic acid, or with other vitamins and minerals as a public health intervention in antenatal care.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (10 January 2015). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) (26 February 2015) and contacted relevant organisations for the identification of ongoing and unpublished studies (26 February 2015) .
SELECTION CRITERIA
Randomised or quasi-randomised trials evaluating the effects of oral preventive supplementation with daily iron, iron + folic acid or iron + other vitamins and minerals during pregnancy.
DATA COLLECTION AND ANALYSIS
We assessed the methodological quality of trials using standard Cochrane criteria. Two review authors independently assessed trial eligibility, extracted data and conducted checks for accuracy. We used the GRADE approach to assess the quality of the evidence for primary outcomes.We anticipated high heterogeneity among trials and we pooled trial results using a random-effects model and were cautious in our interpretation of the pooled results: the random-effects model gives the average treatment effect.
MAIN RESULTS
We included 61 trials. Forty-four trials, involving 43,274 women, contributed data and compared the effects of daily oral supplements containing iron versus no iron or placebo.Preventive iron supplementation reduced maternal anaemia at term by 70% (risk ratio (RR) 0.30; 95% confidence interval (CI) 0.19 to 0.46, 14 trials, 2199 women, low quality evidence), iron-deficiency anaemia at term (RR 0.33; 95% CI 0.16 to 0.69, six trials, 1088 women), and iron deficiency at term by 57% (RR 0.43; 95% CI 0.27 to 0.66, seven trials, 1256 women, low quality evidence). There were no clear differences between groups for severe anaemia in the second or third trimester, or maternal infection during pregnancy (RR 0.22; 95% CI 0.01 to 3.20, nine trials, 2125 women, very low quality evidence; and, RR 1.21; 95% CI 0.33 to 4.46; one trial, 727 women, low quality evidence, respectively), or maternal mortality (RR 0.33; 95% CI 0.01 to 8.19, two trials, 12,560 women, very low quality evidence), or reporting of side effects (RR 1.29; 95% CI 0.83 to 2.02, 11 trials, 2423 women, very low quality evidence). Women receiving iron were on average more likely to have higher haemoglobin (Hb) concentrations at term and in the postpartum period, but were at increased risk of Hb concentrations greater than 130 g/L during pregnancy, and at term.Compared with controls, women taking iron supplements less frequently had low birthweight newborns (8.4% versus 10.3%, average RR 0.84; 95% CI 0.69 to 1.03, 11 trials, 17,613 women, low quality evidence), and preterm babies (RR 0.93; 95% CI 0.84 to 1.03, 13 trials, 19,286 women, moderate quality evidence). They appeared to also deliver slightly heavier babies (mean difference (MD) 23.75; 95% CI -3.02 to 50.51, 15 trials, 18,590 women, moderate quality evidence). None of these results were statistically significant. There were no clear differences between groups for neonatal death (RR 0.91; 95% CI 0.71 to 1.18, four trials, 16,603 infants, low quality evidence), or congenital anomalies (RR 0.88, 95% CI 0.58 to 1.33, four trials, 14,636 infants, low quality evidence).Twenty-three studies were conducted in countries that in 2011 had some malaria risk in parts of the country. In some of these countries/territories, malaria is present only in certain areas or up to a particular altitude. Only two of these studies reported malaria outcomes. There is no evidence that iron supplementation increases placental malaria. For some outcomes heterogeneity was higher than 50%.
AUTHORS' CONCLUSIONS
Supplementation reduces the risk of maternal anaemia and iron deficiency in pregnancy but the positive effect on other maternal and infant outcomes is less clear. Implementation of iron supplementation recommendations may produce heterogeneous results depending on the populations' background risk for low birthweight and anaemia, as well as the level of adherence to the intervention.
Topics: Anemia, Iron-Deficiency; Dietary Supplements; Female; Folic Acid; Humans; Infant, Low Birth Weight; Infant, Newborn; Iron; Iron, Dietary; Pregnancy; Pregnancy Complications, Hematologic; Pregnancy Outcome; Prenatal Care; Randomized Controlled Trials as Topic
PubMed: 26198451
DOI: 10.1002/14651858.CD004736.pub5 -
Ciencia & Saude Coletiva Mar 2019To evaluate the effect of vitamin A supplementation in postpartum infants and women on serum retinol levels and breast milk. The databases Medline, PubMed, Lilacs and...
To evaluate the effect of vitamin A supplementation in postpartum infants and women on serum retinol levels and breast milk. The databases Medline, PubMed, Lilacs and SciELO were consulted. The descriptors used were vitamin A, dietary supplement, child, postpartum period, infant and nutrition programs policies. Search found 7432 articles. After elimination of duplicity and application of eligibility criteria, 8 studies remained. All evaluated the effect of vitamin A supplementation on immediate postpartum, five studies used retinyl palmitate supplementation, one with retinyl palmitate and two did not specify the form of supplementation. Six studies evaluated colostrum and two included supplementation of children. It was found that supplementation in the puerperium increases the concentrations of serum retinol and breast milk, however, this result was in the short term and was relevant when the previous concentrations of the mother were low. When maternal serum concentrations are adequate, the retinol content in milk does not change, with little relevance for children. Further studies should be performed to evaluate the effect of megadoses supplementation on serum concentrations of children.
Topics: Colostrum; Dietary Supplements; Diterpenes; Female; Humans; Infant, Newborn; Milk, Human; Postpartum Period; Pregnancy; Retinyl Esters; Time Factors; Vitamin A; Vitamin A Deficiency
PubMed: 30892504
DOI: 10.1590/1413-81232018243.07112017 -
Nutrients Jan 2023Diabetes disrupts one in six pregnancies, bestowing immediate and long-term health risks to mother and child. Diet and exercise are commonly prescribed to control... (Meta-Analysis)
Meta-Analysis Review
Nutritional and Exercise-Focused Lifestyle Interventions and Glycemic Control in Women with Diabetes in Pregnancy: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.
Diabetes disrupts one in six pregnancies, bestowing immediate and long-term health risks to mother and child. Diet and exercise are commonly prescribed to control dysglycemia, but their effectiveness across sub-populations and types of diabetes (type-1; type-2; or gestational diabetes mellitus, GDM) is uncertain. Therefore, a systematic review and meta-analysis on the effect of diet and/or exercise on glycemia in pregnant women with diabetes was conducted. Random effects models were used to evaluate effect sizes across studies and anticipated confounders (e.g., age, ethnicity, BMI). Of the 4845 records retrieved, 26 studies (8 nutritional supplements, 12 dietary, and 6 exercise interventions) were included. All studies were conducted in patients with GDM. Overall, supplement- and exercise-based interventions reduced fasting glucose (−0.30 mmol/L; 95% CI = −0.55, −0.06; p = 0.02; and 0.10 mmol/L; 95% CI = −0.20, −0.01; p = 0.04); and supplement- and diet-based interventions reduced HOMA-IR (−0.40; 95% CI = −0.58, −0.22; p < 0.001; and −1.15; 95% CI = −2.12, −0.17; p = 0.02). Subgroup analysis by confounders only confirmed marginal changed effect sizes. Our results suggest a favorable role of certain nutritional supplements, diet, and exercise practices on glycemia in women with GDM and underline a lack of evidence in ~20% of other diabetes-related pregnancies (i.e., women with pre-existing diabetes).
Topics: Female; Humans; Pregnancy; Diabetes, Gestational; Diet; Glycemic Control; Life Style; Randomized Controlled Trials as Topic
PubMed: 36678193
DOI: 10.3390/nu15020323 -
Nutrients Oct 2022(1) Background: Whey protein (WP) in combination with resistance training (RT) is beneficial in improving sarcopenic obesity and its damaging effects in older adults,... (Meta-Analysis)
Meta-Analysis
(1) Background: Whey protein (WP) in combination with resistance training (RT) is beneficial in improving sarcopenic obesity and its damaging effects in older adults, while the difference between men and women should be considered while interpreting results. This review aims to investigate WP's efficacy on postmenopausal women with or without RT; (2) Material and Methods: We searched electronic databases including PubMed, EMBASE, and the Cochrane Library from inception to August 2021 for randomized controlled trials that included comparison groups to evaluate WP's efficacy in women aged 55 years and above. The outcomes included body composition, muscular strength, functional capacity, and dietary intake. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were used to estimate the effect of WP. We also performed subgroup analysis with or without RT; (3) Results: We included 14 studies in the systematic review and 10 studies in the meta-analysis. Subgroup analyses showed RT was a major confounder for muscle strength, lean mass, and dietary protein intake (PI). In the RT subgroup, WP supplementation had a significant positive effect on biceps curl strength (BC) (SMD: 0.6805, 95% CI: 0.176, 1.185, : 0%), and lower limb lean-mass (LLLM) (SMD: 1.103, 95% CI: 0.632, 1.574, : 14%). In the subgroup without RT, a significant negative effect on PI (SMD: -0.4225, 95% CI: -0.774, -0.071, : 47%) was observed, while no significant effect on muscle strength or lean mass was revealed. WP supplementation did not show a significantly different effect on fat mass or body weight loss in both the subgroups; (4) Conclusions: In postmenopausal women, WP supplementation only in combination with RT enhances BC and LLLM compared to placebo controls. Without RT, WP has no significant benefit on muscle strength or lean mass.
Topics: Aged; Body Composition; Dietary Proteins; Dietary Supplements; Female; Humans; Male; Muscle Strength; Muscle, Skeletal; Postmenopause; Resistance Training; Whey Proteins
PubMed: 36235862
DOI: 10.3390/nu14194210