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Soy Bad, Soy Good: What You Must Know When Considering Soy-Based Foods

I've long shared the many issues and dangers associated with including soy in your diets. One of the biggest concerns: soy contains phytic acid, which has

anti-nutritional properties. Because phytic acid binds with specific nutrients you need, like iron, it inhibits their absorption in your digestive system.

That fact alone should make you think twice about using soy in your diets. But is there any safe and beneficial form of soy? Yes.

From a nutritional standpoint, you should think of soy in two categories: soy that is non-fermented, and soy that is fermented. The troubles I've documented on this site are associated with using primarily processed, non-fermented soy foods such as soy milk, flour, nuts, baby formula and the many soy products that have been flooding the market recently.

However, studies have shown traditionally fermented soy--which is the form that is wildly popular in many Asian cultures--aids in preventing and reducing a variety of diseases including certain forms of heart disease and cancers. Why? Fermentation blunts the effect phytic acid has on your system.

Fermentation also creates the probiotics--the "good" bacteria that your body is absolutely dependent on, such as lactobacilli--that increase the quantity, availability, digestibility and assimilation of nutrients in the body.

Natto, tempeh and miso are a few examples of fermented soy products. In one study, the culturing process in making miso, a traditional Japanese fermented soy food that contains isoflavone aglycones, genistein and daidzein, which are believed to be cancer chemopreventatives, led to a lower number and rate of cancers. Researchers said it was not the presence of any specific nutrient that was cultured along with the soyabean paste but rather the cultured soy medium itself that was responsible for the health benefits associated with miso consumption.

Well Being Journal Vol. 11, No.6

Contra Costa Times July 14, 2004