Is Soy Bad For You?
July 14, 2015

TofuSoy has recently caught a bad rap on health blogs and in the press. But are the fears warranted? If so, it would be a shame, because soy adds wonderful texture and variety to a whole-foods, plant-based diet. Tofu, soy milk, tempeh, and texturized soy protein are rich in protein; soy sauce and miso can amp up flavor in any dish. We looked at the current research and discovered the pros and cons of soy.

Why is soy so controversial?

Several concerns have cast doubt on soy’s healthiness: some people are allergic to soy. A small portion of the population with certain health conditions do not benefit from soy. For example, this study on breast cancer survivors found that soy intake was linked to lower bone mineral density. Men worry that the estrogen in soy will make them more feminine. Parents worry that soy will effect their kids’ sexual development. Modern soy sauce contains artificial caramel coloring that may be carcinogenic. Lastly, as most of the soybeans grown in the US are genetically-modified, some may worry about the potential negative effects of eating GMO’s.

Most of these worries are unsupported by science or easy to avoid.

Research does not show any significant effect of everyday soy consumption on testosterone levels or sperm production. Soy is associated with reduced risk of prostate cancer in men. Soymilk consumption has no demonstrated impact on male puberty, but may delay female puberty (in contrast to cow’s milk. Early puberty in girls is associated with increased breast cancer risk). While the dangers of GMO foods remain unclear, it is possible to buy non genetically-modified soy milk, tofu, and other soy products. High quality, authentic soy sauces like this brand don’t use coloring.

As with any nutrient or food, eating too much soy might not be very good for us. Researchers have not beensoybeans able to find a high level of soy consumption that has led to health problems, but a minimum of 25 grams of soy protein per day contributes to cholesterol reduction and most of the other reported health benefits of soy.

Consider soy’s many benefits.

As an alternative protein source, soy makes a great substitute for meat and dairy products. Several studies strongly support eating soy products to reduce cholesterol.   Although the supporting evidence isn’t as strong, other potential benefits include cancer prevention, reduction of menopause symptoms, and improved cognitive function. Additionally, an analysis of data from the Singapore Chinese Health Study finds that adults who got more of their protein from soy products were less likely to develop gout compared to adults whose protein came primarily from fish.

Bottom line: For most people, eating soy products can be really beneficial. Unless your doctor or pharmacist has specifically instructed you to limit or avoid soy, don’t give too much thought about throwing that block of tofu or carton of soy milk in your shopping cart. Of course, avoid soy if you are allergic to it. And since soy has estrogen in it, it should be used cautiously or limited in adults with hormone-sensitive conditions or cancers (breast/ovarian/uterine cancer, thyroid issues, endometriosis, etc.). Otherwise, enjoy.