Eligible Participants
- Generally healthy adults, 30-65 years of age
- Having moderately elevated LDL-cholesterol but not taking lipid-lowering medications
- Having a Framingham risk score of ≤10% based on gender, age, LDL-cholesterol, HDL-cholesterol, blood pressure and diabetes
Study Design
Twenty-eight participants were randomly assigned to drink one of 3 types of milk for 4 weeks, in a cross-over design: a whole soy bean (WB) beverage, a soy protein isolate (SPI) beverage, or a dairy milk (DM) as control. All participants drank all 3 types of milk. Each type of milk provided 25 grams of protein, consistent with the FDA health claim. Fasting blood samples were collected at the beginning, in the middle (at 15 days), and at the end of each 4-week milk phase to measure blood lipids, insulin, and blood sugar.
Conclusions
The results of this study show that a 25-gram dose of daily soy protein from soy milk led to a modest 5% lowering of LDL-cholesterol compared to dairy milk in adults with moderately elevated concentrations. The effect was virtually identical for the two distinct types of soy milks - one made from whole soy beans and one from soy protein isolate. Neither soy milk significantly affected other lipid variables, insulin or glucose.