If you want a healthy heart, eat tofu daily as eating food that contains higher amounts of isoflavones is linked to a moderately lower risk of heart disease.

Isoflavones are a type of polyphenol found in legumes, including soybeans, chickpeas, fava beans, pistachios, peanuts and other fruits and nuts.

Soybeans are the richest source of isoflavones, and soy foods and ingredients contain varying concentrations of isoflavones.

After eliminating a number of other factors known to increase heart risk, the researchers found that consuming tofu, which is high in isoflavones, more than once a week was associated with an 18 per cent lower risk of heart disease, compared to a 12 per cent lower risk for those who ate tofu less than once a month.

Tofu
Tofu Wikimedia Commons

Analysis of data from 200,000 people

Published in the journal Circulation, the study from Harvard Medical School and Brigham and Women's Hospital analysed 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.

The favourable association with eating tofu regularly was found primarily in young women before menopause or postmenopausal women who were not taking hormones.

"Despite these findings, I don't think tofu is by any means a magic bullet. Overall diet quality is still critical to consider, and tofu can be a very healthy component," said study lead author Qi Sun from Harvard University.

Soymilk, on the other hand, tends to be highly processed and is often sweetened with sugar.

The study found no significant association between soymilk consumption and lower heart disease risk.

"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," Sun said.

"Tofu and other isoflavone-rich, plant-based foods are excellent protein sources and alternatives to animal proteins," he added.

For the study, researchers analysed health data of more than 74,000 women from the Nurses' Health Study (NHS).

The researchers emphasized that the study should be interpreted with caution because their observations found a relationship but did not prove causality.

Many other factors can influence the development of heart disease, including physical exercise, family history and a person's lifestyle habits, they added.