New US research has found eating foods like tofu that are rich in isoflavones could lower an individual’s risk of heart disease.
Carried out by researchers at Harvard Medical School and Brigham and Women’s Hospital, the new study analysed data gathered from more than 200,000 people who were all free of cancer and heart disease at the start of the study.
The participants were asked to complete surveys about their diet every two to four years, while data on heart disease was collected from medical records.
The findings, published in Circulation, the flagship journal of the American Heart Association, showed that after taking into account factors that potentially increase heart disease risk, eating tofu more than once a week was associated with an 18 percent lower risk of heart disease, compared to a 12 percent lower risk for those who ate tofu less than once a month.
In addition, this link was found to be particularly strong among the young female participants and in postmenopausal women who were not taking hormones.
Lead study author Qi Sun, MD, ScD commented on the results, saying that they are in line with statistics from countries such as China and Japan, where individuals traditionally consume a diet high in isoflavones thanks to foods such as tofu, and also tend to have a lower risk of heart disease compared to those who eat a diet high in meat and low in vegetables.
However, Sun adds that the health benefits of isoflavones still need more research.
“Despite these findings, I don’t think tofu is by any means a magic bullet,” said Sun. “Overall diet quality is still critical to consider, and tofu can be a very healthy component.”
“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,” he said. “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 added that the findings do not show a cause-and-effect relationship, just an association between isoflavones and heart disease risk.
Many other factors can also influence the development of heart disease, including physical exercise, family history and a person’s lifestyle habits.
“For example, younger women who are more physically active and get more exercise tend to follow healthier, plant-based diets that may include more isoflavone-rich foods like tofu. Although we have controlled for these factors, caution is recommended when interpreting these results,” said Sun.
As well as being found in tofu, a soybean curd, high amounts of isoflavones can also be found in whole soybeans such as edamame. However, the study found no link between soy milk, which is often highly processed and sweetened with sugar, and a lower risk of heart disease.
Other sources of isoflavones include chickpeas, fava beans, pistachios and peanuts.