THURSDAY, July 25, 2002 (HealthDayNews) -- When it comes to cardiovascular health, any soy is good soy.
Or so says new research, which found that both high- and low-isoflavone soy significantly improved cholesterol profiles in men and women and also reduced systolic blood pressure in men.
The results of the study, published in the August issue of the American Journal of Clinical Nutrition, actually fill in another step toward building a diet that may one day replace medication to control cholesterol.
"We're building up complement diets which contain a combination of a number of recognized cholesterol-lowering foods. Our aim is to be able to rival drug therapy or give people an opportunity to select a diet to do the same thing as drug therapy by stacking up the advantages that you can get from individual foods," says Dr. David Jenkins, lead author of the study and a professor of medicine and nutritional sciences at the University of Toronto and St. Michael's Hospital.
Some of the other cholesterol-lowering foods in what Jenkins calls his "portfolio diet" are oats, barley and nuts (especially almonds).
Soy isoflavones are supposed to have a number of cardiovascular benefits, although it hasn't been clear whether the isoflavones themselves are responsible.
The latest study looked at 23 men and 18 post-menopausal women, all of whom had elevated cholesterol levels. The participants were put on three successive diets, each lasting one month and all low in saturated fat.
Protein in the control diet came from low-fat dairy products and egg substitutes. In the two soy diets, one high in isoflavones and one low in isoflavones, protein came from different soy products commonly found in health food stores including soy milk, soy yogurt, soy dogs, soy links and soy burgers.
Unlike many previous studies, the soy protein sources were what could easily be eaten by the general public, Jenkins says.
When all had been drunk and eaten, no major differences were found between the two soy protein diets with regards to their beneficial effect on blood lipids and blood pressure.
However, other experts urge caution before you swap your chicken, fish and egg whites for soy substitutes.
"Soy is a good low-fat protein option for people. It is heart healthy, [but] it is too early to tell if soy is beneficial for both sexes in reducing blood pressure," says Dr. Nieca Goldberg, chief of the Cardiac Rehabilitation and Prevention Center at Lenox Hill Hospital in New York City. "Larger studies need to be done on both sexes to measure the effects of soy on blood pressure."
Studies show that people need to eat more than 25 grams of soy -- which equals four cups of soy milk -- each day to reduce their LDL, or "bad," cholesterol, says Goldberg, who is also the author of Women Are Not Small Men -- Life-Saving Strategies for Preventing and Healing Heart Disease in Women.
What To Do
For more information on soy and cholesterol, visit the American Heart Association. The National Heart, Lung, and Blood Institute has more on lowering your cholesterol.
