Finally the record is set straight about soy, estrogen, testosterone... and moobs
Soy is always a topic of controversy with men because of their unwarranted fear of one thing: the dreaded “moobs”. Yes, you read right. Man boobs.
So what is soy and why should you care?? Well, the soybean is a great source of protein, which is very rare coming from veggies. Soy also contains isoflavones. Isoflavones are believed to mimic the hormone estrogen in the body, and are sometimes called phytoestrogens. And dudes, while the hormone sounds feminine, you naturally have low levels of estrogen. Even your beloved manliest man in the universe, Arnold, and yes, even you, creatine-using-bcaa-supplementing-eat more to burn more-gym-rat. In the same way, females produce some testosterone.
There is discussion all over the internet about whether these phytoestrogens in soy foods are helpful or harmful. The majority of the fact and research-based discussion points towards soy being helpful- in reducing risk of prostate cancer, breast cancer, alzheimers, and even high cholesterol. But not everyone agrees with that- a few studies say it may be harmful to thyroid function and may cause breast cancer. And a 2006 study from the American Heart Association didn't find any conclusive evidence either way. Ugh. Holy headache.
So, back to men and soy. Soy has been around in China, Japan and other Asian cultures for thousands of years and has been in millions of men's diets since childhood. It doesn't look like it's had an effect on masculinity or male sexual development. Nor does it look like it’s had an effect on fertility.
And the most recent study out there agrees with this: Published in The American Society for Reproductive Medicine, (July 2000) found that soy foods and soy isoflavone supplements have NO significant effect on male reproductive hormones.
Studies shmudies, lets get to what I know you care about. Waking up one day with boobs. The real name for the development of male breasts is called Gynecomastia. Gynecomastia can be caused by puberty, steroid abuse, obesity, tumors, genetic disorders, liver disease and aging.
In a few cases of gynecomastia, soy intake has been questioned as a possible culprit. Soy has not been proven to be the "cause", but in those cases, men were ingesting MASSIVE quantities of it. We’re talking quarts and quarts of soy milk and tofu every day. Which would totally be contradictory with our lifestyle of everything in moderation, right!?
Bottom line: There doesn't seem to be much risk for development of gynecomastia with normal, moderate soy intake.
If you are overly concerned, then fine, go coffee instead of soy latte with breakfast, then a gallon of soy-powder protein shake made with soy milk and soy ice cream, then tofu and edamame for dinner. No one should. But a glass of soy milk a day, 3-4 oz tofu, or a serving of edamame? Doubtful there will be any harm in that. Don't go overkill on the soy "meats" (textured soy protein) and the soy isoflavone supplements, though. They are totally over-processed; gross.
If you’re adding protein powder to smoothies and meals, whey and soy are fairly comparable. Whey protein comes from milk, and because it’s an animal source, it has a “higher biological value” and higher protein utilization than soy. In normal people talk, this means our bodies can digest and use the amino acids in it more easily. But before you go loading up on the whey, soy has the edge in other areas, like amino acids glutamine and arginine that help increase muscle mass. So don’t get yourself caught up in this anti-soy hype, there are plenty of benefits to moderate intake. And that’s the straight up scoop on soy, its nutrition facts, and its correlation to moobs ladies and gents!