Anyone who’s been following bodybuilding and health magazines over the years is aware of the negative stigma attached to soy. Bodybuilders have been taught one thing over and over again: soy is an inferior protein for muscle building. As new evidence comes in, many of the assumptions regarding soy have now changed.

Soy originally fell out favor with many health conscious persons due to the phytoestrogens found in raw soy products. Phytoestrogens are compounds that have weak estrogenic activity. This led to claims that soy will raise estrogen levels in humans, not good if one is looking to gain lean muscle mass. Estrogen has always been one of the most dreaded compounds for bodybuilders. Although estrogen has some anabolic properties, high levels of estrogen can cause water retention, gynecomastia and increased body fat. The fear of estrogenic side effects is what drove many of the misconceptions about soy.

Much of the anti-soy crusade was originated by supplement makers, eager to tout whey as the superior protein choice for the health conscious crowd. While soy was said to be acceptable for physically inactive, bodybuilders were told they needed something better. In the gyms, whey became the preferred way of getting the extra protein that athletes needed to fuel their workouts.

Now here’s the part that most of the soy critics fail to mention. While soy is indeed rich in estrogenic compounds, it does not appear to raise estrogen levels. A recent study that used male monkeys found that soy proteins had no effect on estrogen levels. This lead researchers to conclude that the effects of phytoestrogens in soy are “tissue specific”, they do not exert systemic estrogenic effects.

Since soy has been bashed for such a long time, it may take a while for the bodybuilding community to view soy in a positive light again. While whey will still undoubtedly remain king, the addition of soy will be of use to anyone seeking soy’s many benefits, notably lowering of the cholesterol and reducing heart disease risk.