The growth of plaque depends on the rapid reproduction of smooth muscle cells, such as are present in an artery wall. Isoflavones, particularly genistein, have been shown to inhibit this process, which is essential for atherosclerosis. It wasn t clear whether the partial benefit seen in the monkeys consuming the lower-isoflavone soy protein was due to the traces of isoflavones remaining or to some other component of soy protein. Another important factor in CVD is a person s tendency to form blood clots, which also stimulate the growth of plaque. Some laboratory studies have shown that genistein potentially interferes with many phases of the blood-clotting system that are believed to promote plaque growth.
Normal arteries respond to the neurotransmitter acetylcholine by dilating, or becoming larger.
The women in this study consumed 40 grams of soy protein per day for 30 days. Brachial artery ultrasound was used to measure vascular function. The FDA agrees, and in October 1999 approved the health claim for soy protein and heart disease. All rights reserved. All rights reserved.