Soy Acts Like Estrogen and Could Cause Breast Cancer

     When someone mentions “tofu,” the most common association we have is with the word “healthy.” (The second most common association, I’d argue, is “tasteless blob,” and that’s coming from a guy who loves the stuff!) Nevertheless, soy has rivaled meat as a primary protein source because it is cholesterol free and cheaper to produce. But does soy have a dark side as well?

Soy Acts Like Estrogen

     Perusing the internet, I happened across an article on Men’s Health that stated a high-soy diet could wreak havoc on the human body. Men, in particular, become “feminized” from eating too much soy – they lose body hair, become flaccid, and sometimes develop breasts! This is due, states the article, to the chemical “genistein” in soy, which is a phytoestrogen – it acts like human estrogen in our bodies.

Soy can make signs like this very confusing.

     “Whoa!” I thought, “This is serious business! I love tofu and I drink soy milk every morning with my cereal… I’m going to turn into a woman! Ahhh!”

     But then I snooped a little further.

Correction: Soy Acts Like Estrogen… In Rats

     Recent 2009 health studies on Japanese women (who eat much more soy than American women) show no increased rates of breast cancer – another fear associated with phytoestrogen. In fact, genistein is a much weaker type of estrogen than what our body naturally secretes. Think of it like comparing a bottle of O’Douls to a glass of wine – they’re both alcohol, but one is far more potent. In that same year, another study suggested that a soy diet can decrease cholesterol values and even prevent breast cancer! Other studies go further to say it could also prevent prostate cancer in men.

     So why are people freaking out?

     A study conducted on rats, not humans, showed that soy-heavy diets lead to an increased rate of cancer. Taken further, the phytoestrogen changed the rats’ body chemistry to a startling degree. This is important, because we use rats for many cancer studies and we often feed those rats soy-based food. If all these rats are developing cancer from what they eat, then the data from treatment tests could be skewed! Many scientists argue that the effect seen in rats could correlate to humans, because, as mammals, our bodies behave in similar ways. But no link has been scientifically proven, yet.

Eh. He kind of looks like my Uncle Jim, but not by much.

     And as for men developing breasts? That was a single case study as reported by Men's Health. Scientists are leery of case studies because they aren't always indicative of a larger trend. For instance: your neighbor wins the lottery; Are you now more likely to win the lottery? The odds say no, but you'd really, really like to think so! This is the problem with listening to the odd story of the man who started developing female sexual characteristics - you might think it could happen to you when the science indicates otherwise...Like I did.


     Not one of my prouder moments...