The Effects of Irvingia gabonensis Seed Extract Supplementation on Anthropometric and Cardiovascular Outcomes: A Systematic Review and Meta-Analysis

Abstract

Background: It has been hypothesized that Irvingia gabonensis can promote weight loss by increasing fatty acid breakdown and inhibiting fatty acid synthesis. Objective: We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of Irvingia gabonensis seed extract supplementation on weight-related health outcomes. Methods: Literature searches were conducted in 4 databases from January 2018 to identify randomized controlled trials (RCTs) investigating the effects of Irvingia gabonensis seed extract supplementation on anthropometric measures and cardiovascular biomarkers. Two investigators independently performed abstract screenings, full-text screenings, data extraction, and risk of bias (ROB) assessments. Random effects meta-analyses were performed when 3 or more RCTs reported the same outcome. Results: Five RCTs met the eligibility criteria for this systematic review. Four of the 5 RCTs were rated as having a high ROB, and only one RCT was rated as having a low ROB. Random-effects meta-analysis of the 5 RCTs showed that a significant decrease in body weight, body fat, and waist circumference was observed in relation to Irvingia gabonensis seed extract supplementation. However, the only one low-ROB trial did not have significantly different outcomes. Meta-analysis also showed beneficial effects of Irvingia gabonensis seed extract supplementation on total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides. Only the low-ROB trial showed a trend of increasing HDL-cholesterol levels (net percent change = 11.61%; 95% confidence interval (CI: -6.12%, 29.34%) and decreasing triglyceride levels (net percent change = -29%; 95% CI: -76%, 19%). The reported adverse events were minor in these 5 RCTs. Conclusions: Overall efficacy of Irvingia gabonensis seed extract supplementation on weight loss seems positive but is limited due to poor methodological quality and the insufficient reporting of the clinical trials. Further high quality RCTs are needed to determine the effectiveness of Irvingia gabonensis seed extract supplement on the weight-related health outcomes.