Registered Dietitian Hy-Vee
---- — Q: I have heard a lot about how healthy soy foods are for me, and that I should be eating or drinking them, but I am a bit leery because of all the talk about soy and breast cancer. Is soy a good choice, or should I avoid it?
A: Soybeans are a widely used, inexpensive and low-calorie way to get large amounts of protein with very little fat and no cholesterol. You can eat soybeans in many forms, including tofu, the beans themselves (also known as edamame), soy milk, miso and soy powder.
Soy is often promoted as a healthy protein alternative for people who would rather not eat meat. Research about the effects of soy on cancer risk reduction has been mixed, but according to BreastCancer.org, the newest research is in support of including whole soy foods into a healthy lifestyle. Studies are not as positive for soy supplements and breast cancer.
There are a lot of health-related benefits of eating whole soy foods. Soy has powerful antioxidants and has been shown to help keep cell growth and activity normal as well as regulate cholesterol.
The soy controversy is related to the fact that most breast cancers are fueled by the female sex hormone estrogen. Isoflavones, found in soy, are weak estrogen-like compounds. We do know that your body's estrogen is much stronger than the estrogen-like isoflavones in soy and may in fact replace the stronger estrogen in cells, which could be a good thing.
Many doctors recommend that women who take hormonal therapy or who have estrogen-receptor-positive breast cancer avoid soy supplements because they contain high concentrations of isoflavones. But in general, it's fine to eat moderate amounts of soy foods (½ cup to 1-1/2 cups per day) as part of a balanced diet. As with other fruits, vegetables and grains, eating the whole food is better than choosing a processed product that is usually depleted of fiber and other nutrients. Most health professionals agree that a healthy balanced diet that includes soy is certainly a good idea, along with plenty of whole grains and fruits/vegetables.
Great ways in include soy into your day would be to include edamame (whole soy beans) in salads, salsas, soups or even casseroles. They add a light taste and creamy texture while bulking up the protein of your meal.
If you are taking hormonal therapy to fight off a hormone-receptor-positive breast cancer, and you are concerned about any phytoestrogen effects, ask your doctor or registered dietitian about how much soy you can eat.