Soy protein supplementation and blood lipid levels in adults
What it found
In adults, taking soy protein supplements was linked to lower total cholesterol, LDL cholesterol and triglycerides, and slightly higher HDL cholesterol.
The analysis pooled 41 randomised controlled trials.
What they found
Studies in people
Total cholesterol
Soy protein supplementation was linked to a significant reduction in mean serum total cholesterol of 5.26 mg/dl.
LDL cholesterol
Mean serum low-density lipoprotein cholesterol fell significantly by 4.25 mg/dl with soy protein supplementation.
Triglycerides
Mean serum triglycerides fell significantly by 6.26 mg/dl with soy protein supplementation.
HDL cholesterol
Mean serum high-density lipoprotein cholesterol rose significantly by 0.77 mg/dl with soy protein supplementation.
Dose response
Meta-regression analyses showed a dose-response relation between soy protein and isoflavone supplementation and net changes in serum lipids.
What the authors conclude
“These results indicate that soy protein supplementation reduces serum lipids among adults with or without hypercholesterolemia.”
Also in their conclusions
- They conclude that soy protein supplementation reduces serum lipids among adults with or without hypercholesterolemia.
- They advise that replacing foods high in saturated fat, trans-saturated fat, and cholesterol with soy protein may have a beneficial effect on coronary risk factors.
How it was done
High cholesterol is a major risk factor for heart disease that can be changed. Studies on whether soy protein lowers cholesterol have given mixed results.
They pooled 41 randomised controlled trials of isolated soy protein supplementation in adults, where soy protein was the only intervention and changes in blood lipids were reported. They searched MEDLINE from 1966 to February 2005 and the bibliographies of retrieved articles.
What it can’t tell you
- We summarised it from the abstract only.
- The analysis pooled short trials of soy protein supplements, so it cannot show the effect of soy foods eaten over many years.
- It cannot show whether any cholesterol changes translate into fewer heart attacks or deaths.
Who paid
- Authors work at
- Tulane University School of Public Health and Tropical Medicine, USA
The paper
- Title
- A meta-analysis of the effect of soy protein supplementation on serum lipids
- Type
- Meta-analysis
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Reynolds K, Chin A, Lees KA, Nguyen A, Bujnowski D, He J (2006). A meta-analysis of the effect of soy protein supplementation on serum lipids. The American journal of cardiology. doi:10.1016/j.amjcard.2006.03.042PubMed 16923451DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error