Say What to Soy?

by Andrea Millar — April 16, 2008

Soy is one of those products, like hemp, with applications far beyond its original form. With uses in biofuel, oil for cooking, paint, candles, food, pharmaceuticals, and clothing, to name a few (offshore clothier Banana Republic just started making clothes from soy silk), soy has proved itself in the eyes of many. And as a crop with an incredibly high yield to square footage of cultivation ratio, it has fans among sustainability advocates across the dietary spectrum. It's chock full of B vitamins and bioavailable protein (on par with milk and eggs), and hey, it absorbs just about any flavor you put it in.

But the record has been tarnished recently with plenty of soy-based controversy. Although initial health claims of soy were enthusiastic, there is some indication that when soy consumption models from Asian countries were adopted in the West, the resulting "super-sizing" may have enlarged the more dubious attributes of the soybean as a food product. Even as a designated superfood, soy in large quantities can, according to many studies, have a negative effect on many.

Unfermented soy has plant estrogens, molecules which can also be utilized as hormones in our own body. Here, however, is where consensus is lost. While the studies have mostly been completed in rats, there is some indication that eating soy in its unfermented state (e.g., tofu, most soy products) may contribute to some breast cancers (rather than guard against them as previously thought), increase estrogen levels in men (this is where its possible protection against prostate cancer comes from, but the possible hormonal imbalance may be considerable), and prevent nutritional absorption of other foods.

However, Tulane University just released a study (found on medscape.com) wherein glyceollin derived from soybeans stopped further growth of certain tumors by interfering with the tumor's ability to respond to estrogen. Antioxidant or carcinogen, soy's baggage is complicated.

So what do we as consumers do? Stay informed. Talk to a medical professional about your health and soy products. As with nearly any food, increasing levels of processing tend to decrease the nutritional value. Pick tofu over soy cheese or soy brats. If you do eliminate soy, research other options for protein (there are many!).