Bodybuilders Should Avoid Soy Protein
By Mark Gilbert
Many of us have heard of the potential negative effects of soy protein in men. Certainly, it is now used as a last resort in baby formula for male babies who are allergic to cow???s milk protein because of case reports of estrogenic effects (girlie traits in males like breast development). One study looked at the effect of males consuming about 60 grams (the equivalent of two large servings) of soy protein daily for a month. The result was that testosterone levels decreased 19 percent and oestrogen-receptor activity increased ??? this is just about the exact scenario that bodybuilders want to avoid because oestrogen makes muscles look soft and lowering testosterone decreases muscle mass, fat-burning and strength.
The researchers continued to track testosterone levels in the subjects for two weeks after removing the soy protein from their diets, just to ensure that it was the soy protein and not some other factor that was messing with their testosterone. As suspected, testosterone returned to normal. Not all studies confirm that soy protein has these effects but until more research is completed, steer clear!
Reference:
Susan Goodin, et al. Cancer Epidemiology Biomarkers & Prevention 2007, 16(4): 829-833.
By Mark Gilbert
Many of us have heard of the potential negative effects of soy protein in men. Certainly, it is now used as a last resort in baby formula for male babies who are allergic to cow???s milk protein because of case reports of estrogenic effects (girlie traits in males like breast development). One study looked at the effect of males consuming about 60 grams (the equivalent of two large servings) of soy protein daily for a month. The result was that testosterone levels decreased 19 percent and oestrogen-receptor activity increased ??? this is just about the exact scenario that bodybuilders want to avoid because oestrogen makes muscles look soft and lowering testosterone decreases muscle mass, fat-burning and strength.
The researchers continued to track testosterone levels in the subjects for two weeks after removing the soy protein from their diets, just to ensure that it was the soy protein and not some other factor that was messing with their testosterone. As suspected, testosterone returned to normal. Not all studies confirm that soy protein has these effects but until more research is completed, steer clear!
Reference:
Susan Goodin, et al. Cancer Epidemiology Biomarkers & Prevention 2007, 16(4): 829-833.
