Polyphenol Supplementation and Sarcopenia: A Systematic Review and Meta-Analysis of Clinical Trials

Background: Experimental evidence suggests that polyphenols, a large group of phytochemicals found in fruits and vegetables, may preserve muscle mass and strength by increasing the expression of anabolic factors and enhancing mitochondrial function. Objectives: This systematic review and meta-analysis aims to summarize the evidence about the effect of polyphenol supplementation on muscle mass, muscle strength, and physical performance in individuals with sarcopenia. Methods: A systematic search was conducted using three databases (PubMed/Medline, Scopus, and Web of Science) from the date of inception to April 2024. Interventional studies examining the effect of polyphenol supplementation on muscle measures and physical performance in middle-aged and older subjects with sarcopenia were included. Results: Of the 344 articles screened, 7 articles were included in the systematic review. Five of the 7 included studies were meta-analyzed, involving a total of 227 patients with sarcopenia. The results showed a statistically significant effect of polyphenols on muscle mass (SMD = 1.50; 95% CI: 0.26, 2.75; Z = 2.36; P = 0.02), no effect on muscle strength (SMD = 0.03; 95% CI: −0.24, 0.30; Z = 0.20; P = 0.84), and a near-significant trend on physical performance (SMD = 0.52; 95% CI: −0.03, 1.07; P = 0.06). Conclusions: Based on the available data, this study provides pooled evidence that treatment with polyphenols may have a beneficial effect on muscle mass in sarcopenic subjects. However, further studies with larger sample sizes are required to substantiate this effect and draw more accurate conclusions.