NEW YORK (Reuters Health) - A Western diet rich in tofu and other soy products may help protect older women from artery disease, new study findings suggest.
According to the report, phytoestrogens were associated with less artery stiffness among more than 400 postmenopausal women. The benefit was most pronounced among the oldest women, or those who had been postmenopausal the longest.
Arterial stiffness increases as the blood vessel disease atherosclerosis progresses, and atherosclerosis can lead to heart attack or stroke, explain researchers in the August issue of Arteriosclerosis, Thrombosis and Vascular Biology: A Journal of the American Heart Association.
The sharp drop in estrogen following menopause is associated with an increased risk of heart disease among women. Phytoestrogens, plant-based estrogen-like compounds found in soy, may mimic the beneficial effects of estrogen on the heart, some research suggests. Soy also contains antioxidants--compounds that neutralize disease-causing free radicals before they can damage cells.
Many studies have demonstrated that Asian populations, which consume far more soy than Western populations as a whole, have lower rates of heart disease--suggesting that this dietary difference might play a role. And soy-based diets have been linked to lower levels of artery-clogging LDL cholesterol.
However, whether phytoestrogens protect against heart disease in the context of a Western diet is not clear.
To investigate, the researchers interviewed postmenopausal women about their diet and used a measure called aortic pulse-wave velocity to gauge stiffness in the aorta, the heart's main artery. The analysis took into account some lifestyle factors that are known to affect the risk of heart disease, such as physical activity, smoking and body mass index (BMI)--a measure of weight in relation to height.
The present study found that phytoestrogens may have a protective effect on the risk of atherosclerosis and arterial degeneration through an effect on arterial walls, especially among older women, Dr. Yvonne T. van der Schouw from University Medical Center in Utrecht, the Netherlands, and colleagues conclude.
However, more research is needed since it is possible that women who consumed the most soy had healthier habits that were not measured in the study, which may protect against heart disease, they note.
SOURCE: Arteriosclerosis, Thrombosis and Vascular Biology 2002;22:1316-1322.