Sunday, January 22, 2006
Raw Soy Lowers Cholesterol Level
Two servings a day of soy protein - such as that found in tofu, soy milk or soy powder - can lower cholesterol levels by as much as 9% as long as the soy is uncooked, a study has said.
Soy-fortified foods in which the soy protein was baked at high temperatures do not provide the benefit, study author James Anderson said.
An 8% to 9% drop in low-density lipoprotein, the so-called bad cholesterol that can lead to heart disease, can be gained from eating uncooked soy protein in the form of two 340 ml servings of soy milk daily, said Anderson, a scientist at the University of Kentucky in Lexington.
The health benefit also is found in such products as soy nuts, soy powder sprinkled on food or in milkshakes.
"Soy protein increases the activity of low-density lipoprotein receptors primarily on the liver that clears it from the body," he said. "Eating soy protein increases the activity of the enzymes that break down the cholesterol."
In the studies reviewed, the cholesterol drop showed up after about a month.
If the recommended two servings of soy were doubled in size, that would lower blood cholesterol by another 1% to 2%, so the optimal effect comes from two modest servings. Eating the soy foods all at once would overwhelm the body's ability to process so they must be consumed in two separate servings, he said, comparing soy to a fast-acting drug that must be taken in doses hours apart.Cooking scrambles the amino acids contained in soy proteins and all but eliminates the health benefit, he said.
