Soy and its constituents have recieved much acclaim for its health promoting effects. As a whole food soy is high in fiber and protein while being low in saturated fats. Taken apart, the soy isoflavones act as phytoestrogens and may protect against cancer, heart disease, and osteoporosis, and the soy protein has proven to lower cholesterol. A recent review published in the American Journal of Cardiology concluded that we may best be served by soy in its whole form versus supplement form when it comes to heart health.
The review took into account information from more than 40 studies that measured the effect of soy protein (isolated) and soy isoflavones (isolated) on cholesterol and triglycerides. The reviewers wanted to determine if either constituent of soy truely lowered cholesterol to a significant value.
Past studies had found some benefit, though small, for lowering the LDL, or bad, cholesterol. So the question became, is it really signficant? And is it really worth buying a supplement?
The lead authors conclude that in fact it may be better to just eat more soy. After reviewing all the data, most of the lowering effects were minimal, usually less than 5 points. But they do not want to discount this effect, in fact, they state that the benefits of soy protein on cholesterol may be amplified if the whole food is eaten.
Because soy contains high amounts of fiber, which also lowers cholesterol, eating the whole food would lower cholesterol via protein and fiber. This is in contrast to a protein supplement that would only work via one mechanism.
And soy is also a excellent source of unsaturated fats, which is also a heart healthy benefit. Foods high in polyunsaturated fats actually work to raise the HDL, or good, cholesterol and lower the LDL cholesterol.
So, when one takes into account the total benefit of soy as a whole food, the total lowering effect on cholesterol is most likely to be greater than 5 points. So get the heart healthy benefits by eating tofu or edamame versus buying a specialized supplement of soy protein that will only work in one way.
Posted by Dr. Christina Gutierrez on October 6, 2006 02:09 PM
