(P13-079-24) The Constraint of Soy Isoflavones on Enhancing Physical Performance: A Meta-Analysis of Randomized Controlled Trials

Objectives: This review aimed to assess the impact of soy isoflavones (ISFs) on physical performance. The decline in physical performance poses a significant risk factor for mortality. ISFs are recognized for improving physiological functions like cardiovascular, metabolic, and neurological systems. However, limited research exists on the influence of ISFs on aspects of physical performance.

Methods: PubMed, EMBASE, and Web of Science were searched until December 2023 to identify randomized controlled trials (RCTs) examining the impact of soy or isolated ISFs on physical performance, encompassing measurements like muscular strength, functional ability, aerobic endurance, and walking capacity. We employed a random effects model for a conservative estimation of the overall effect size, utilizing the standardized mean difference (SMD) to standardize results across different units. Subgroup analyses categorized individuals by diverse health statuses, ISFs dosages, intervention durations, and populations.

Results: Eight studies (816 participants) meeting inclusion criteria predominantly focused on middle to elderly-aged Caucasians, primarily postmenopausal women. Two trials included men. Most participants were healthy, with one study targeting stroke-induced hemiparesis and another involving hemodialysis patients. The duration of ISFs intervention varied from 8 weeks to 1 year, with ISF doses ranging from 40 to 165 mg/day. In studies incorporating exercise as an additional intervention, the independent effects of ISFs were isolated. The meta-analysis of 6 studies (383 participants) indicated a marginally significant effect of ISFs on physical performance (SMD=0.70; 95% confidence interval [CI], -0.02~1.41; p=0.06; I²=88%). Notably, subgroup analyses revealed a distinct effect in patients with stroke or renal failure (SMD, 0.62; 95%CI, 0.04~1.20; p=0.04, I²=0).

Conclusions: ISF supplementation doesn’t significantly improve physical performance, potentially attributed to significant heterogeneity in the ISFs treatment approach. However, ISFs have notable benefits for individuals with stroke and renal failure, regardless of exercise intervention, indicating their potential as a dietary supplement for those with chronic conditions limiting physical exercise.

Funding Sources: None