(P16-02-26) Impact of Soy Protein on Blood Lipids: A Systematic Review and Meta-Analysis of Randomized Trials to Support Health Claims for Cholesterol and Cardiovascular Risk Reduction

Objectives: In light of ongoing discussion around soy protein and heart health claims, we conducted a systematic review and meta-analysis of randomized trials of the effect of isolated soy protein (ISP) on blood lipids.

Methods: We searched MEDLINE, Embase, and The Cochrane Central Register through December 17, 2025. We included randomized trials ≥3 weeks of the effect of ISP interventions compared with a non-soy-containing control on blood lipids in adults with or without dyslipidemia. Two independent reviewers extracted data and assessed risk of bias. The primary outcome was low density lipoprotein cholesterol (LDL-C) and secondary outcomes were total cholesterol (TC), high density lipoprotein (HDL-C), triglycerides (TG), non-HDL-C, and apolipoprotein B (apo B). Data were pooled using the inverse variance method and expressed as a mean difference (MD) with 95% confidence intervals (95% CI). Heterogeneity was assessed (X²) and quantified by (I²). Certainty of evidence was assessed using GRADE. ClinicalTrials.gov, NCT04861545.

Results: We included 90 trials (K=139 trial comparisons) in 5,547 participants with various health statuses. The median ISP dose was 30 g/d with a median follow-up of 8 weeks. ISP reduced LDL-C (K=135; MD -0.15 mmol/L [-0.18, -0.12 mmol/L]); TC (K=136; -0.16 mmol/L [-0.20, -0.12 mmol/L); TG (K=118; -0.10 mmol/L [-0.15, -0.05 mmol/L]); non-HDL-C (K=132; -0.19 mmol/L [-0.22, -0.15 mmol/L]); and apo B (K=47; -0.05 g/L [-0.07, -0.04 g/L]); and increased HDL-C (K=132; 0.03 mmol/L [0.01, 0.04 mmol/L]), compared with a non-soy control. No dose response was seen. The certainty of evidence was assessed as high for LDL-C, TC, HDL-C, and non-HDL-C and moderate for TG and apo B (downgrades for imprecision).

Conclusions: Updated evidence for LDL-C, TC and an expanded set of established lipid targets reinforces the existing health claims for soy protein and heart health. There is a reliable indication that ISP at a median dose of 30g/d results in small important reductions in LDL-C and TC as well as non-HDL-C and trivial improvements in HDL-C in adult individuals with varying health conditions. There is good indication for small important reductions in apo B and trivial reductions in TG.

Funding Sources: SNI Global, USSEC, and IFF