Effect of plum supplementation on blood pressure, weight indices, and C-reactive protein: A systematic review and meta-analysis of randomized controlled trials.

Abstract

Metabolic syndrome and its components are major health concerns around the world. Among various factors, overweight/obesity, its consequent inflammation, and hypertension are of special importance. Plums are anti-oxidant-rich fruits which have long been investigated for their health benefits. In this systematic review and meta-analysis, we investigated the possible impact of plum supplementation on obesity, inflammation, and blood pressure. All of the major databases (PubMed, Scopus, Cochrane, and Web of Science, Google Scholar and EMBASE) were searched to obtain the articles eligible for the review. Relevant data was extracted for the final analysis. Weighted mean difference (WMD) was obtained using fixed and random effect models. The main outcomes included systolic and diastolic blood pressure, body weight, body mass index (BMI), body fat percentage, waist circumference (WC) and blood C-reactive protein (CRP) levels. The effect sizes were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). Crude search provided 3121 articles, among which 11 were eligible to be included. After crude and subgroup analysis, we were unable to detect any significant impact of plum supplementation on body weight (weight mean difference (WMD) of 0.04kg; 95% CI:-1.55, 1.63, p=0.959), BMI (WMD 0.39kg/m2; 95% CI:-0.11, 0.90, p=0.125), body fat percentage (WMD=0.59%; 95% CI:-0.41, 1.59, p=0.249), waist circumference (WMD=0.60cm; 95% CI:-1.83, 3.04, p=0.627), systolic blood pressure (WMD -1.24mmHg; 95% CI:-3.08, 0.59, p=0.185), diastolic blood pressure (WMD -4.32mmHg (95% CI:-9.29, 0.65, p=0.089), or inflammation indicated by C-reactive protein (CRP) levels (WMD=0.23mg/l; 95% CI:-0.27, 0.73, p=0.371). Our results show that plum supplementation has no positive effect on factors of metabolic syndrome. We recommend that further research in the form of clinical trials be conducted to make a clear conclusion as of the effectiveness of plum supplementation on parameters of metabolic syndrome.