There's an idea going around that breast cancer, ovarian cancer, and other female cancers may have a correlation with soy products and that men who consume too much soy may be at risk for gynecomastia (commonly called "man-boobs"). Soy is generally considered safe for the public, but I'm going to take that deeper and look at all sides of the issue.
What is in soy that causes these concerns?
Soybeans have Isoflavones in them, which is just a super fancy word for chemical compounds that our bodies recognize as being "estrogen-like". These Isoflavones are polyphenolic groups, which, before I go into full high school chemistry teacher mode, are compounds in plants that are now being recognized for their cancer fighting properties. In addition to soybeans, polyphenols are found in green tea, blueberries, olives, spinach, and apples among others. These are foods that are well known as cancer-fighting, or soldiers that can be responsible for warding it off in the first place.
The Gray Area
GMOs or genetically modified organisms are also generally considered safe for consumption. I struggle with this some. GMOs are often the way of life, they are evolutionary, all broccoli is a GMO, it was a man-made hybridization. Puggles and Goldendoodles are GMOs, and they're adorable, but some GMOs can take things too far. When Soy is genetically modified, it can contain unsafe levels of formaldehyde as well as having those "estrogen-like" isoflavones go awry, that's where my concern for GMO soy comes in.
The increase of isoflavones can cause human estrogen levels to rise, but there isn't significant proof that soy alone can cause levels to rise high enough to impact human tissue or cause gynecomastia. In one case of soy-related gynecomastia, the individual was drinking 3 quarts of soy milk per day, and when he stopped the condition reversed itself. If gynecomastia presents other factors may be at play. But as previously mentioned, using organic, non-GMO soy is a good way of preventing additional risk.
Soy can absolutely be a part of a healthy and balanced diet, but moderation in all things is key. I believe that in the case of soy products, organic non-GMO is the best way to go. Choose a variety of protein sources whether or not you are vegetarian, and maybe limit your soy to one serving per day. Non-GMO tofu is only about .79 cents more than conventionally produced tofu at my local store, which makes it $1.99 per pound, cheaper than even most conventional meats.
Do you eat soy products? What do you think?