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, 1 meta-analysis reported a moderate beneficial effect of soy isoflavones containing soy protein on reducing C-reactive protein (CRP) levels in adults with chronic inflammatory diseases, while 2 studies found neutral effects in mixed or clinical populations. The predominant effect direction is beneficial with a moderate effect size, and effects were typically observed over a median duration of 90 days. The evidence base is small, with no clear dose range or specific form identified across studies.
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.