The Soy-Breast Cancer Connection: Oh No! Not My TOFU!

Patient Expert

Soy milk (and creamer, and smoothies"). Edamame. Soy sauce. Soy nuts. Thanksgiving recipes for "tofurkey." Soy energy bars. Soy crackers, soy flour bread. TOFU I believe the only food I have yet to see re-created with soy is chocolate" Hey, I just googled it, and guess what? I found a source for soy chocolate, right there with soy coffee (and I'm NOT going there!)

The soybean is a ubiquitous part of the world's food supply. Grown in China since at least 664 B.C., when the first written records of its cultivation appear, more than half the world's soybean crop is now produced here in America. When noted scientist and educator Dr. George Washington Carver started researching crops for black farmers to grow, back in the 1880s, he looked hard at soybeans before settling on peanuts. Yes, we might have been eating soybean-butter and jelly sandwiches all these years" Now, soy has become a part of our everyday lives, even though the vast majority of us don't recognize it. Read the fine print on the back of a chocolate bar, and you may very well see soy lecithin listed as an ingredient. The dressing you're drizzling over your salad may include soybean oil. And the TVP (textured vegetable protein) in your veggie burger? Soy.

Soybeans have zoomed in popularity in recent years; from 2001-2004, over 1600 new foods containing soy were added to American supermarket shelves. Much of this growth has been fueled by FDA-backed claims that soy reduces the risk of heart disease. It's also a good source of omega-3 fatty acids which, if you've been paying attention at all, you know are supposed to be good for your cholesterol. Soy is a complete protein with a low glycemic index, beloved by some dieters. In short, it seems to have everything going for it" except taste. And that's what they make curry powder and chili oil for, right?

So along comes this claim that soy may spur the growth of breast tumors. Whaaaaaa"? Dr. William Helferich, professor of food science and nutrition at the University of Illinois, has spent ten years studying the health effects of isoflavones, found in high concentrations in soy products. He and his colleagues have demonstrated that one particular isoflavone found in soy, genistein, "stimulates the growth of estrogen-receptive tumors." Seventy percent of women with breast cancer have estrogen-receptive tumors. In addition, they found that genistein interferes with tamoxifen, the primary drug therapy for women with ER-receptive breast cancer.

WHOA! Before you run into the kitchen and pour your Silk or White Wave down the drain, hold on. Helferich goes on to say that our chief concern should be the use of isoflavones, including genistein, in natural alternatives to HRT, those over-the-counter remedies that are supposed to quell your hot flashes and PMS "safely, naturally." The amount of genistein in these products is hard to track. "Women are participating in an ongoing experiment with an unknown outcome," said Helferich. "You can't identify what dose of isoflavones you're getting."

He adds that his research shows that soy itself, rather than its extracted isoflavones, administered alone, does NOT make tumors grow. "When the whole food is consumed you get a very different effect than if you consume the concentrated constituents individually. The whole soybean is healthier than many of its individual chemical parts," he concludes.

So, you might want to think twice about that "natural" remedy for menopause symptoms. But if you love your chocolate soy shake, your tofu lasagna, and that Soy Dream ice cream you just discovered in the freezer case, munch on. At this point, the benefits of soy in your diet seem to far outweigh the possibility of it being a breast cancer risk. WHEW! And I was just about to toss that recipe for soybean pie I make every Thanksgiving"