People who regularly eat tofu and other foods containing isoflavones have a moderately lower risk of developing heart disease, according toa study published in Circulation.

Researchers at Harvard Medical School and Brigham and Women’s Hospital analyzed data from more than 200,000 people who participated in three prospective health and nutrition studies. All participants were free of cancer and heart disease when the studies began. After controlling for a number of other factors known to increase heart risk, the researchers found that consuming tofu more than once a week was associated with an 18% lower risk of heart disease, compared to those who ate tofu less than once a month. The results were particularly favorable for younger women and for postmenopausal women not taking hormones.

“Despite these findings, I don’t think tofu is by any means a magic bullet,” said lead study author Qi Sun, M.D., Sc.D., a researcher at Harvard’s T.H. Chan School of Public Health in Boston. “Overall diet quality is still critical to consider, and tofu can be a very healthy component.” Populations that traditionally consume tofu, such as China and Japan, tend to have lower heart disease risk compared to populations that follow a generally meat-rich and vegetable-poor diet.
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Sun also noted that not all soy is created equal: Tofu and whole soybeans are rich sources of isoflavones, but soymilk tends to be highly processed and sweetened with sugar, and no significant association was found between soymilk consumption and lower heart disease risk. Other foods high in isoflavones include chickpeas, fava beans, pistachios, peanuts, and other fruits and nuts.

Sun’s recommendation: “Other human trials and animal studies of isoflavones, tofu, and cardiovascular risk markers have also indicated positive effects, so people with an elevated risk of developing heart disease should evaluate their diets. If their diet is packed with unhealthy foods, such as red meat, sugary beverages, and refined carbohydrates, they should switch to healthier alternatives. Tofu and other isoflavone-rich, plant-based foods are excellent protein sources and alternatives to animal proteins.”

Sun also noted that this study is observational, and cannot prove causality.