Eating two servings a day of soy protein (found in soy foods such as tufu, soy milk or soy powder) can lower cholesterol levels by nine percent.
However, the soy foods should be made from raw or uncooked soy to preserve the active protein. Because of this, soy-supplemented muffins, cereals or nutritional bars do not offer the same benefit due to the high temperature used to prepare these foods.
Beneficial soy products include soy nuts, soy powder sprinkled on food or in milkshakes, or edamame, a raw or parboiled edible form of soybeans popular in Japan, Dr. James Anderson (University of Kentucky in Lexington).
Two servings a day is the optimal dose for the effect, and it would also be better if served as one serving at a time twice a day rather than two servings once a day.
Dr. James Anderson analyzed 57 previous studies on soy protein's effect on blood cholesterol, and presented his findings at a scientific conference on soy in Chicago this week, according to Reuters.
The cholesterol-lowering effect manifests itself after one month of soy consumption, previous studies found.
"Soy protein increases the activity of low-density lipoprotein receptors primarily on the liver that clears it from the body," Reuters quoted Dr. Anderson as saying. "Eating soy protein increases the activity of these enzymes that break down the cholesterol."
Source: University of Kentucky in Lexington