TUESDAY, Oct. 11, 2022 (American Heart Association News) -- Let's talk tofu.
It seemed like such a simple, honest food when it caught your eye in the grocery store. But later, after you checked it out online, you began to worry that a long-term relationship might get complicated.
It's true that health experts' passion for tofu can be seen as a bit of an on-again, off-again affair. It's also true, despite some rumors you might have heard, that tofu can be an excellent part of a healthy eating pattern for most people.
"It's a very nutritious food," said Dr. Qi Sun, an associate professor of nutrition and epidemiology at Harvard T.H. Chan School of Public Health in Boston.
Tofu, sometimes called bean curd, is mostly soybeans and water, plus a coagulant such as calcium sulfate, that's pressed into a block. In mainstream U.S. supermarkets, you're likely to see a few varieties sorted by firmness, which reflects water content. "Silken" tofu is unpressed and can be as thick as custard, while firmer varieties can be more like a soft cheese.
In China, where tofu may have originated around 200 B.C., it takes on many additional forms and flavors – sheets and sticks, fermented and smoked. Across Asia, it's served fried, marinated and stuffed.
Seasonings may vary, but "they all fall in the umbrella of tofu," Sun said.
Nutritionally, tofu offers much to love. According to the U.S. Department of Agriculture, half a cup of firm tofu offers 21.8 grams of protein with 181 calories and 11 grams of fat. Most of that fat is of the healthy polyunsaturated kind.
The high level of protein makes tofu a good alternative to animal-derived meat. Federal dietary guidelines include tofu as part of a healthy vegetarian dietary pattern, and a 2021 American Heart Association scientific statement emphasizes choosing plant-based proteins for heart health.
Tofu also contains all the essential amino acids your body needs and is rich in minerals and vitamins, including calcium, manganese, iron and vitamin A.
Tofu and other soy foods also are primary source of isoflavones. Those are flavonoids – plant-created chemicals that are associated with a variety of health benefits.
But tofu, soy products and isoflavones "do not have a consistent positive image in the United States," Sun said, because of a complicated history.
In 1999, the Food and Drug Administration allowed soy products to claim they were protective against coronary heart disease. Then, a 2006 AHA science advisory concluded that cardiovascular benefits from soy isoflavones were "minimal at best."
The FDA began re-evaluating the heart health claim in 2007, and in 2017 proposed revoking it.
But research has continued. Sun was senior author on a 2020 study published in Circulation that looked at data from more than 210,000 U.S. health care professionals and found that those eating at least one serving of tofu a week had an 18% lower risk of heart disease compared with those who rarely ate tofu.
And in a 2021 study in the European Journal of Nutrition that included about half a million people in China, those without a history of cardiovascular disease who ate soy four or more days a week had lower odds of dying from a heart attack compared with people who never or rarely ate soy.
Still, tofu and other soy products also make some people wary because isoflavones function like a weak form of the hormone estrogen. But concerns that soy can cause infertility or other problems in men are "not based on science at all," Sun said. Similarly, the American Cancer Society sees no dangers from eating soy.
"For the vast majority of people, it should be reasonable to incorporate tofu in their daily diet without any issues," Sun said.
He and his family eat "probably three servings per week," Sun said. He likes using soft tofu in soups and firm tofu – frozen and cut up – in a traditional Chinese hot pot.
Foodies celebrate tofu for its ability to absorb the flavor of whatever it's cooked with. "I mean, there's almost unlimited ways to incorporate tofu in your diet," Sun said.
Not all those ways are good for you, though. People should avoid preparations with excess sugar, salt or saturated fat. If you do that, Sun said, tofu can be "a very healthy food, almost universally."
American Heart Association News covers heart and brain health. Not all views expressed in this story reflect the official position of the American Heart Association. Copyright is owned or held by the American Heart Association, Inc., and all rights are reserved. If you have questions or comments about this story, please email email@example.com.
By Michael Merschel, American Heart Association News