What About Soy?
MORE: What about soy? A few years ago, it sounded like a magic bullet for menopause, breast cancer. Now the latest reports show that it may actually raise the risk of cancer.
MW: "Well, it's interesting -- when we looked at the breast cancer risks in China versus here, we found that Chinese women had much, much lower hormone levels in their bodies. [The hormone estrogen can fuel the growth of breast tumors.] We thought soy might be one reason, because it binds with the estrogen receptors in the breast. But it is really up in the air. It may be the dose is critical, and that phytoestrogens may have both negative and positive effects. I get calls from breast-cancer patients who are on Tamoxifen [a drug that reduces the risk of recurrence by blocking the effects of estrogen], and they ask if they should be taking soy products. It's probably not wise."
MORE: What about using soy to relieve the symptoms of menopause?
MW: "Based on the Chinese data, I did a research project with women who were having more than five hot flashes a day. We gave half of them 45 milligrams of phytoestrogens a day in a protein bar, and the others got a placebo bar. There was no difference in the number or intensity of hot flashes."
MORE: Is there a difference if soy is in a processed product versus, say, tofu?
MW: "If you're using soy as a protein source, then the number of protein grams are pretty much the same [product to product]. But, depending on how they process soy, there will be different levels of phytoestrogens. We've sampled products; they vary."
BDH: "It's hard to know what to track. There are so many compounds in soy, and nobody knows what the active agents are. Some may be active in bones and some active in other systems like hormones. It's a free-for-all."
MORE: With soy, are we looking at an HT-type situation, where something we thought would help might turn out to be harmful?
MW: "If you are using soy as a food, as the Asian population does, I would feel comfortable with that. But, as soon as you're using it as a 'super supplement,' then you wouldn't want to do that. We keep looking for a magic food, but it really is the eating pattern that counts."
