Substituting soy nuts for other protein sources in a healthy diet appears to lower blood pressure in postmenopausal women, and also may reduce cholesterol levels in women with high blood pressure, according to a report in the May 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
The American Heart Association estimates that high blood pressure (hypertension) affects approximately 50 million Americans and 1 billion individuals worldwide. The most common-and deadly-result is coronary heart disease, according to background information in the article. Women with high blood pressure have four times the risk of heart disease as women with normal blood pressure.
Francine K. Welty, M.D., Ph.D., and colleagues at
At the beginning of the study, 12 women had high blood pressure (140/90 milligrams of mercury or higher) and 48 had normal blood pressure. "Soy nut supplementation significantly reduced systolic [top number] and diastolic [bottom number] blood pressure in all 12 hypertensive women and in 40 of the 48 normotensive women," the authors write. "Compared with the TLC diet alone, the TLC diet plus soy nuts lowered systolic and diastolic blood pressure 9.9 percent and 6.8 percent, respectively, in hypertensive women and 5.2 percent and 2.9 percent, respectively, in normotensive women."
In women with high blood pressure, the soy diet also decreased levels of low-density lipoprotein ("bad") cholesterol by an average of 11 percent and levels of apoliprotein B (a particle that carries bad cholesterol) by an average of 8 percent. Cholesterol levels remained the same in women with normal blood pressure.
"A 12-millimeter of mercury decrease in systolic blood pressure for 10 years has been estimated to prevent one death for every 11 patients with stage one hypertension treated; therefore, the average reduction of 15 milligrams of mercury in systolic blood pressure in hypertensive women in the present study could have significant implications for reducing cardiovascular risk and death on a population basis," the authors write.
"This study was performed in the free-living state; therefore, dietary soy may be a practical, safe and inexpensive modality to reduce blood pressure. If the findings are repeated in a larger group they may have important implications for reducing cardiovascular risk in postmenopausal women on a population basis," they conclude.
(Arch Intern Med. 2007; 167:1060-1067.)