Myth-buster
A meta-analysis found soy protein with isoflavones lowered CRP by 0.49 mg/L in people with chronic inflammatory diseases — but this is essentially a replay: 2 of the 3 included studies had previously found no effect.
For people with ongoing inflammatory conditions, soy protein containing isoflavones may modestly reduce systemic inflammation as measured by C-reactive protein, but the overall evidence remains weak because most individual trials have not found a benefit.
CRP is a blood marker of inflammation; higher levels are linked to heart disease, arthritis, and other chronic conditions. This meta-analysis combined 3 clinical trials and calculated a small but statistically significant drop in CRP with soy protein plus isoflavones — yet two of those three trials individually saw no change. So while the overall result looks promising, it's not yet a settled finding.
Where this fits in the evidence
Pillser has synthesized 3 studies on Soy Protein for Reduced C-Reactive Protein Levels — overall evidence strength: Low.
Across 3 studies, one meta-analysis reported a moderate beneficial effect of soy protein on reducing C-reactive protein (CRP) in adults with chronic inflammatory diseases, while two other studies (a meta-analysis and an RCT) found no significant effect. The predominant effect size is mixed (small to moderate). The median study duration was 90 days, and the most studied dose was 40 g/day.
The study
- Meta-Analysis
- 2025-05-12
- Journal of health, population, and nutrition
This is a plain-language summary of a research finding, not medical advice. Pillser surfaces research signals to help you decide what's worth investigating — always consult a qualified professional before changing what you take.