Comparative effects of nutraceuticals on body weight in adults with overweight or obesity: A systematic review and network meta-analysis of 111 randomized clinical trials.

There is no research on the comparative effects of nutraceuticals on weight loss in adults with overweight or obesity. This study aimed at quantifying and ranking the effects of different nutraceuticals on weight loss. We searched PubMed, Scopus, and Web of Science to November 2022. We included randomized trials evaluating the comparative effects of two or more nutraceuticals, or compared a nutraceutical against a placebo for weight loss in adults with overweight or obesity. We conducted random-effects network meta-analysis with a Frequentist framework to estimate mean difference [MD] and 95% confidence interval [CI] of the effect of nutraceuticals on weight loss. One hundred and eleven RCTs with 6171 participants that investigated the effects of 18 nutraceuticals on body weight were eligible. In the main analysis incorporating all trials, there was high certainty of evidence for supplementation of spirulina (MD: -1.77 kg, 95% CI: -2.77, -0.78) and moderate certainty of evidence that supplementation of curcumin (MD: -0.82 kg, 95% CI: -1.33, -0.30), psyllium (MD: -3.70 kg, 95% CI: -5.18, -2.22), chitosan (MD: -1.70 kg, 95% CI: -2.62, -0.78), and Nigella sativa (MD: -2.09 kg, 95%CI: -2.92, -1.26) could result in a small improvement in body weight. Supplementations with green tea (MD: -1.25 kg, 95%CI: -1.68, -0.82) and glucomannan (MD: -1.36 kg, 95%CI: -2.17, -0.54) demonstrated small weight loss, also the certainty of evidence was rated low. Based on our findings, supplementations with nutraceuticals can result in a small weight loss in adults with overweight or obesity.

Dose-dependent effect of vinegar on blood pressure: A GRADE-assessed systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: There are controversial findings regarding the effect of vinegar on blood pressure based on the evidence accumulated so far. METHODS: A systematic search was conducted through PubMed, Scopus, and ISI Web of Science up to April 2022. We estimated the change in blood pressure for each 30 ml/d increments in vinegar consumption in each trial and then, calculated the mean difference (MD) and 95 %CI using a fixed-effects model. A dose-response meta-analysis of differences in means provided us with the estimation of the dose-dependent effect. The certainty of evidence was rated by the GRADE tool. RESULTS: Each 30 ml/d increment in vinegar consumption reduced SBP by - 3.25 mmHg (95 %CI: - 5.54, - 0.96; I2 = 67.5 %, GRADE = low). Levels of SBP decreased linearly and slightly (Pnonlinearity = 0.69, Pdose-response = 0.02) up to vinegar consumption of 30 ml/d (MD30 ml/d: - 3.36, 95 %CI: - 5.77, - 0.94). Each 30 ml/d increment in vinegar consumption reduced DBP by - 3.33 mmHg (95 %CI: - 4.16, - 2.49; I2 = 57.1 %, GRADE = low). Levels of DBP decreased linearly and slightly (Pnonlinearity = 0.47, Pdose-response = 0.004) up to vinegar consumption of 30 ml/d (MD30 ml/d: - 2.61, 95 %CI: - 4.15, - 1.06) CONCLUSIONS: According to the findings, vinegar significantly reduces systolic and diastolic blood pressure and may be considered an adjunct to hypertension treatment. Thus, clinicians could incorporate vinegar consumption as part of their dietary advice for patients.