What are the health benefits of soy? Could too much soy be bad for you?
Over the past few weeks, I’ve gotten a whole bunch of questions about soy: Is soymilk better for you than cow’s milk? Can eating more soy help prevent osteoporosis, heart disease, or hot flashes? Are the health benefits of soy over-hyped?
Many of you have also written to ask about negative things you’ve heard about soy. Is too much soy bad for you? Are certain soy foods better than others? Should pregnant women or children avoid soy?
There’s a lot to talk about. This week, we’ll take a closer look at the alleged health benefits of soy and see how the evidence stacks up in favor of soy as a health food. Next week, I’ll investigate the charges against soy and whether we have as much to fear as some claim.
Soy Goes Mainstream
Soy has always been popular with vegetarians because it’s an inexpensive source of high-quality vegetarian protein. Lately, though, it’s become much more mainstream. It’s not just a substitute for animal products anymore. Now, it's being promoted as a way to make your diet healthier.
Once upon a time, for example, the only people who drank soy milk were vegetarians or those who were allergic to cow’s milk. Now, half the dairy case at the grocery store is occupied by soy milk, which is being pitched as a sort of nutritional upgrade from regular milk.
Nutritionally, they are fairly similar, but that’s only because soymilk manufacturers work hard to make them that way. Most soymilk contains added Vitamin A, D, and calcium, making it comparable to cow’s milk. Soymilk is free of cholesterol and saturated fat, however, and contains a couple of grams of fiber—which milk does not.
Soy has something else that cow’s milk doesn’t have, and that’s the right to make the following USDA-approved health claim: Diets that include 25 grams of soy protein a day (and are also low in fat and cholesterol) may reduce the risk of heart disease. That’s because eating foods containing soy protein can lower your cholesterol levels. So far, we don’t know why that is.
In order to get 25 grams of soy protein, you’d have to drink about 4 glasses of soymilk. Of course, there are a lot of other ways to get soy protein. You can eat steamed soybeans (otherwise known as edamame), tofu, soy yogurt, soy burgers, or bread made with soy flour.
In general, it’ll take you about four servings of whole soy foods like tofu or edamame to get to 25 grams of protein. With a more concentrated form, like a soy protein powder, it takes a lot less.