Soy protein and blood fats across 41 trials in adults
What it found
In adults, soy protein lowered total cholesterol, LDL cholesterol, and triglycerides while slightly raising HDL cholesterol.
The changes were seen across 41 trials.
What they found
Studies in people
Total cholesterol dropped
Taking soy protein lowered average total cholesterol by 5.26 mg/dl compared with control groups.
LDL cholesterol fell
Soy protein reduced LDL cholesterol, often called bad cholesterol, by 4.25 mg/dl.
Triglycerides went down
Blood triglyceride levels fell by 6.26 mg/dl with soy protein supplementation.
HDL cholesterol rose slightly
HDL cholesterol, often called good cholesterol, increased by 0.77 mg/dl.
Dose-response pattern
Larger amounts of soy protein and its plant compounds called isoflavones led to bigger changes in blood fats.
What the authors conclude
- They state that soy protein lowers blood fats in adults, whether or not they already have high cholesterol.
- They suggest swapping foods rich in saturated fat, trans fat, and cholesterol for soy protein may help reduce heart disease risk factors.
How it was done
High cholesterol is a major changeable risk factor for heart disease. Earlier studies gave mixed results on whether soy protein lowers blood fats.
The authors gathered 41 randomized controlled trials in adults where isolated soy protein was the only change made. They combined the results to measure shifts in blood fat levels over each trial's follow-up period.
What it can’t tell you
- We summarised it from the abstract only.
- These trials measured blood fats but did not track actual heart attacks or strokes over time.
- Because the trials varied in length and design, the exact daily amount needed for these changes is not pinned down here.
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 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error