Soy Compound Lowers Blood Pressure, Stroke Risk
A new study examines how a certain naturally-occurring component of soy may enhance the function of arteries in stroke patients, and help all Americans keep heart healthy. According to the Center for Disease Control and Prevention, heart disease is the nation's number one killer while stroke is the third leading cause of death in the United States.
The study, published recently in the European Heart Journal by researchers at the University of Hong Kong, found a diet rich in soybeans and soy isoflavones boosts artery health. Isoflavones are natural compounds found in soy that, although different from the hormone estrogen, do exert a mild estrogen-like effect under certain conditions.
The researchers recruited 102 stroke patients, randomly assigned daily intake of 80 mg soy isoflavones supplements to 50 patients and gave a placebo to the remainder for 12 weeks. The study found that the participants who consumed soy isoflavones had a significant increase in flow-mediated dilation, the measure of a blood vessel's healthy ability to relax.
The dilation of arterial blood vessels leads to a decrease in blood pressure and reduces the risk of stroke. The researchers note, "These findings may have important implications for the use of isoflavone for secondary prevention in patients with cardiovascular disease, on top of conventional treatments."
"While most Americans only consume 3 milligrams of soy isoflavones per day, compared to 25 to 50 milligrams in Japan and parts of China, it's actually quite simple to increase your isoflavones intake with a few inexpensive additions to your shopping list" added Joy Blakeslee, RD. Ms. Blakeslee suggests a few options:
-- Tofu: 1/2 cup serving contains 25mg isoflavones
-- Low-fat soy flour: 1/4 cup serving contains 50 mg isoflavones
-- Fortified soymilk: 1 cup serving contains 43mg isoflavones
-- Roasted soynuts: 1/4 cup serving contains 78 mg isoflavones
-- Canned soybeans: 1/2 cup serving yields between 40-78 mg isoflavones (depending on whether you pick green, black or yellow soybeans)
Ms. Blakeslee emphasizes, "Soyfoods are the only significant dietary source of isoflavones."
Soy isoflavones offer other potential benefits beyond heart health for warding off some effects of aging. The largest and longest trial to date found soy isoflavones reduce hot flashes by 50 percent. Other research suggests that soy isoflavones reduce bone breakdown, increase bone formation and increase bone mineral density in postmenopausal women. Finally, research suggests soy isoflavones may help prevent some types of cancer.