Does the Grape Products Intake has an Effect on Body Weight in Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

INTRODUCTION: There is a growing interest in the considerable benefits of grape products intake, as some studies have indicated that they may improve cardiometabolic risk factors. However, the widespread impact of grape products on the anthropometric indices is not fully resolved. METHOD: The purpose of this systematic review and meta-analysis was to examine the effects of grape products intake on anthropometric indices in adults. Randomized controlled trials (RCT) examining the effects of grape products intake on anthropometric indices, published up to December 2021, were identified through PubMed, SCOPUS, and ISI Web of Science databases. 30 studies with 35 effect sizes, including 1284 participants (708 cases and 576 controls), were included and analyzed using a random-effects model to calculate weighted mean differences (WMDs) with 95% confidence interval (CI). RESULT: The outcomes have revealed grape products intake to significantly decrease body weight (p = 0.001) and body mass index (p = 0.004) in obese participants, and also, a greater effect was observed when grape seed extract was used. CONCLUSION: Our study suggests that grape products intake may help to decrease body weight in obese participants. Future large RCTs with longer duration and obese populations are needed to expand our findings.

The effects of vitamin C supplementation on glycemic control in patients with type 2 diabetes: A systematic review and meta-analysis.

BACKGROUND AND AIM: It has been suggested that taking vitamin C supplements may improve glycemic control in patients with type 2 diabetes mellitus (T2DM). However, there has not been a thorough evaluation of the actual impact or certainty of the findings. This systematic review and meta-analysis was conducted to determine the effect of vitamin C supplementation on glycemic profile in T2DM patients. METHODS: A systematic search was performed across online databases including Scopus, Web of Science, and PubMed/Medline to identify relevant randomized controlled trials (RCTs) published until July 2022. A random-effects model was applied for the meta-analysis. RESULTS: The present meta-analysis included a total of 22 RCTs with 1447 patients diagnosed with T2DM.A pooled analysis revealed a significant decrease in levels of serum hemoglobin A1c (HbA1c), fasting insulin, and fasting blood glucose (FBG) in vitamin C-treated T2DM patients compared with their untreated counterparts. The dose-response evaluation displayed a substantial linear association between the intervention duration and changes in serum HbA1c levels. However, the analysis did not demonstrate any significant effect of vitamin C on serum values of homeostasis model assessment of insulin resistance(HOMA-IR) in diabetic patients. Subgroup analyses indicated that high-dose vitamin C administration (≥1000 mg/d) considerably decreased serum HOMA-IR levels. CONCLUSION: These findings suggest that long-term (≥12 weeks) and high-dose vitamin C supplementation (≥1000 mg/d) may ameliorate glycemic profile in T2DM patients. However, additional high-quality RCTs are necessary to validate these results.

The effects of Gymnema Sylvestre supplementation on lipid profile, glycemic control, blood pressure, and anthropometric indices in adults: A systematic review and meta-analysis.

There is a growing interest in the considerable health benefits of Gymnema Sylvestre (GS) supplementation, as some studies have reported that it may improve cardiometabolic risk factors. However, the widespread impact of GS supplementation on the parameters mentioned above is not fully resolved. Consequently, this study aimed to examine the effects of GS supplementation on lipid profile, glycemic control, blood pressure, and anthropometric indices in adults. Eligible randomized controlled trials (RCT), published up to November 2021, were identified through PubMed, Scopus, and ISI Web of Science databases. Six studies were included and analyzed using a random-effects model to calculate weighted mean differences (WMDs) with 95% confidence intervals (CI). All studies were conducted in adults that used a GC supplement (>1 week) and assessed our selected cardiovascular risk factors. Outcomes revealed that GS supplementation significantly decreased triglyceride (p < .001), total cholesterol (p < .001), low-density lipoprotein (p < .001), fasting blood sugar (p < .001), and diastolic blood pressure (p = .003). Some limitations, including notable heterogeneity, low quality of studies, and lack of diversity among research participants, should be considered when interpreting our results. Our outcomes suggest that GS supplementation may improve cardiovascular risk factors. Future large-high-quality RCTs with longer duration and various populations are needed to firmly establish the clinical efficacy of the plant.

The Effects of Omega-3 Supplementation on Resting Metabolic Rate: A Systematic Review and Meta-Analysis of Clinical Trials.

BACKGROUND: It is uncertain if omega-3 polyunsaturated fatty acids are associated with increase in resting metabolic rate (RMR) in adults. OBJECTIVE: The aim of the present study was to evaluate the overall effects of omega-3 on RMR. METHODS: Both PubMed and Scopus libraries were searched up to April 2021. Study quality was assessed using the Jadad scale. Random- and fixed-effects models were utilized in order to obtain pooled estimates of omega-3 supplementation impacts on RMR, using weight mean difference (WMD). RESULTS: Seven studies including a total of 245 participants were included. There was significantly higher FFM-adjusted RMR in the intervention group than the control group (WMD: 26.666 kcal/kg/day, 95% CI: 9.010 to 44.322, p=0.003). Study quality showed that four of seven included studies were of high quality. However, there was no significant difference in results in the subgroup analysis according to the quality of studies. Subgroup analyses revealed significant changes for sex (for women: WMD = 151.793 kcal/day, 95% CI = 62.249 to 241.337, p=0.001) and BMI (for BMI > 25: WMD = 82.208 kcal/day, 95% CI = 0.937 to 163.480, p=0.047). Influence analysis indicated no outlier among inclusions. CONCLUSION: The current study depicted that omega-3 polyunsaturated acids can significantly increase RMR in adults. However, further assessments of omega-3 supplementation therapy are critical to monitor its long-term outcomes and potential clinical application.