Research synthesisHigh evidenceSmall effect9 studies · 6 beneficial · 3 neutral · 0 harmful
Across 9 studies, 6 reported beneficial effects of soy protein on reducing blood cholesterol, predominantly with small-to-moderate effect sizes (e.g., total cholesterol reductions of 10.4% in one RCT or -20.55 mg/dL in a meta-analysis). Effects were typically observed over 8-12 weeks (median study duration 135 days), primarily in clinical populations such as adolescents with overweight/obesity, chronic kidney disease patients, and postmenopausal women. The most studied doses ranged from 10–40 g/day.
- Effective dose range: 10-40 g/day
- Studied populations: clinical populations (adolescents with overweight/obesity, chronic kidney disease, type 2 diabetic nephropathy, postmenopausal women, men after prostatectomy)
Caveats: Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Additionally, three neutral studies (including two RCTs with durations up to 2 years) suggest that in some populations—particularly older men after prostatectomy—soy protein does not significantly affect cholesterol, indicating benefit may depend on baseline cholesterol levels or specific health conditions.
Generated Jul 17, 2026