The effects of grape products on metabolic syndrome risk factors: A systematic review and meta-analysis

Background

Grape supplementation has been suggested to contribute to improving parameters related to metabolic syndrome (MetS); however, the scientific literature in this field is controversial and inconclusive.

Objectives

We undertook a systematic review and meta-analysis of randomized controlled clinical trials on the effect of grape product on metabolic syndrome components, including blood pressure, anthropometric measurements, and glycemic and lipid profiles.

Methods

The online databases of PubMed, Scopus, Web of Science, and SciELO were systematically searched for relevant publications until December 2021. The review has been registered at PROSPERO (CRD42021287813). To compare the effects of grape product (seed extract, powder, extract, fruit, pomace, juice) with placebo, the mean differences with 95% confidence intervals (CI) were pooled based on the random-effects model. Subgroup analyses were performed to identify the source of heterogeneity, and assessment of study quality was conducted using the GRADE approach.

Results

In total, 27 randomized controlled trials (RCTs) were included in this systematic review, and 21 trials were selected for meta-analysis. Meta-analyses of the data showed that grape products had a significant effect on lipid levels, decreasing total and low density lipoprotein cholesterol and triacylglycerol levels. Grape supplementation also reduced systolic and diastolic arterial pressure. In addition, grape supplementation increased glucose serum and insulin levels. We found no significant differences in anthropometric measurements.

Conclusion

grape products may be beneficial for individuals with parameters related to MetS because they may have hypotensive and hypolipidemic properties.