People often ask me whether soy is good or bad. Women, in particular, want to know if eating soy foods reduces or increases the risk of breast cancer.
The question comes up because soybeans contain isoflavones, which are plant estrogens (or phytoestrogens). Many women have heard that the estrogen-like effect of these isoflavones is either helpful or harmful when it comes to breast cancer. And while other legumes like lentils and peas also contain isoflavones, the concentration in soybeans is much higher.
So, what’s the deal? While it does seem confusing at times, the research is pretty consistent. Soy does help prevent breast cancer.
In fact, studies show that eating soy foods like tofu cuts breast cancer risk by 30 to 50 percent. Even among women who already have breast cancer, eating soy cut their risk of dying by up to 50 percent, according to a 2007 study in Cancer Epidemiology, Biomarkers & Prevention and a 2009 study in the Journal of the American Medical Association. So, soy helps women with breast cancer live longer, too.
On a related note, studies also show that eating soy foods cuts diabetes risk in half, doubles weight loss for people on diets, and reduces cardiovascular disease and bad cholesterol.
But here’s something else to keep in mind. All soy foods on the market are not created equally. Among the healthiest soy foods are edamame (baby soybeans in the pod eaten raw or cooked), tofu (bean curd in a cake form), tempeh (fermented soybeans in a cake form used like tofu), and miso (fermented soybeans in a thick paste often used in soups).
Among the unhealthiest soy foods are soy chicken nuggets, soy pepperoni, soy sausage, soy cheese, soy ice-cream…you get the picture. These highly processed creations may help us transition from familiar animal foods to wholesome plant foods, but it’s better to see them as a path, not a destination.
And let me leave you with one final note. The same women who ask me about soy foods and breast cancer seldom ask me whether meat increases the risk of breast cancer. But I’ll answer it anyway. The risk of breast cancer increases by 56 percent for each 100 grams of meat women eat every day, according to a 2008 study in Nutrition and Cancer. That’s the equivalent of raising your breast cancer risk by more than 50 percent just by eating a daily piece of chicken.
Is it worth the risk? In my view, that’s the real question.
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Question: While soy can a healthy part of you diet, how does industrial agriculture of a lot of soy factor into your decision making process (if at all?). Monsato, patented soy beans, pesticides, etc….
I’ve been an on-again-off-again vegetarian for a few years, and recently recommitted myself to 45 days of vegetarian. (I realized I do better with challenging but achievable goals). I hope to extend that indefinitely and make the switch to vegan. But I also want to do it in a way that doesn’t ignore the way issues intersect.
Subscribing to your blog now
PS Happy 2 weeks to book release!
Thanks for pointing the facts out on the difference between eating real soy products and processed foods made with soy. I’ve been transitioning back to a vegetarian diet once again but this time, I’m using whole foods rather than relying on the meat replacers like I have done in the past. I am being particularly careful to purchase only organic soy beans and tofu because like Brian, GMO’s cannot be ignored. Your site has been really helpful to that end:)
Congratulations on the book too. I will be ordering it the next time I place a book order.