Jeremy Piven is back in the news again. In a previous blog we talked about Piven’s mercury poisoning from eating too much sushi. Now the Entourage actor is claiming that drinking too much soy milk has caused him to get “man-boobs.” Speaking to Bang Media International, Piven reports that “I was the guy that dabbled in soy milk, but now I’ve found out soy milk has enough estrogen for me to grow breasts. I had to put the soy milk down. It was a very confusing time.” Apparently Piven was drinking 12 cups of soy milk a day- that’s the equivalent of 360 mg of isoflavones (soy estrogen) a day!
Gynecomastia (so called “man-boobs”) is the overgrowth of breast tissue in men. It should be noted that there is an increase in breast tissue itself, which is differentiated from increased breast size due to an increase in fat in overweight men. Contrary to popular belief, males produce both testosterone and estrogen, although the levels of estrogen are much lower than the testosterone levels. There are times when gynecomastia is considered “normal”- typically times when estrogen level may naturally be proportionally higher:
Other causes of gynecomastia include:
Soy is a plant, a member of the pea family. Soy contains protein, isoflavones, and fiber, all thought to providehealth benefits. Soy is an excellent source of dietary protein,including all essential amino acids. Soy isoflavones and lecithin have been studied scientifically for numerous health conditions. Isoflavones such asgenistein are believed to have estrogen-like effects in the body, andas a result are sometimes called “phytoestrogens.”
There is very little evidence that soy estrogens cause gynecomastia. We did find one scholarly paper of a case of possible soy-induced gynecomastia (see soy estrogen casebook), but most studies do not support the notion that soy products are a major cause of “man-boobs.” As most studies do not use doses over 150 mg/day, we cannot comment about Mr. Piven’s specific claims.