Recently, I was with a group of girlfriends and the subject of our morning coffee came up. My one friend noted she drank hers with “tons” of soy milk each morning – prompting lots of agreement from the table. I stayed quiet (I am wary of soy milk), but another friend piped up and basically took the words right out of my head. “So, I love soy milk,” she said. “But I heard it’s really bad for you. I actually heard it could cause cancer.” Cue: deathly, all-consuming silence at our table.
Is soy bad for you? I decided to do some research, so you don’t have to.
Let’s first talk about the soy romanticized by health nuts the world over: fermented soy. This is an ancient ingredient found in Asian foods like natto and miso. Like a lot of fermented foods, it’s rich in probiotics, which help to encourage the growth of good gut bacteria. Furthermore, this form of soy is high in vitamins like K2, which helps to promote heart and bone health. This soy is really very good for you.
Unfermented soy, on the other hand, hasn’t gone through the all-important process of fermentation. This is the soy that we eat today in things like off-the-shelfsoy milk, tofu, and vegetarian “meats.”
Because it’s unfermented, it’s both harder to digest and devoid of all that wonderful good bacteria, vitamins, and minerals. It’s also a highly processed food; about 90% of all U.S. soybeans are genetically modified. The risks of consuming GMO foods are still relatively unknown to us, but recent research compiled by Harvard University points to issues like infertility and developmental issues in children.
But what’s with the whole cancer thing, you ask? I wondered that, too. In short: Unfermented soy has something called phytoestrogens (more specifically, isoflavones). These are plant compounds that act like estrogen in the body. If you’re a woman consuming foods that increase your estrogen levels, you’re at risk for endocrine disruption and hormonal imbalances, including breast cancer. In fact, recent research has noted that eating soy – because of the isoflavones – may “turn on” genes linked to breast cancer.
So. Is soy bad for you? If you can get your hands on some fermented soy, have at it. Otherwise, I’d steer clear from that soy hot dog and chow down on a grass-fed organic beef burger instead.