We include soy as one of the World's Healthiest Foods, and for good reason. It's the most widely grown and utilized legume in the world (at approximately 210 million tons per year worldwide), with about 13,000 years of cultivation and over 5,000 research studies. There are studies that show soy to help regulate blood sugar, blood pressure, and estrogen balance. And there are studies showing soy intake to help prevent colon, breast, and prostate cancer as well as atherosclerosis and post-menopausal hip fracture. It's seldom the case that a whole, natural food can be this widely used and studied for such a long period of time and be found to have a predominantly negative impact on our health.
Yet, like all foods, soy is not a "magic bullet." It needs to be incorporated into a person's Healthiest Way of Eating in a balanced and individualized way. I believe that soy needs to be eaten in moderation like it is in Asia where it has been linked with promoting health. In Japan, for example, individuals seldom consume large quantities of soy at one time as has often become the case with a "burger-replacement" type approach taken in the United States. The research makes it clear that when soy foods are consumed, traditional preparation methods—including the use of traditionally fermented soy products like fermented tofu, fermented miso, and fermented soy sauce—are best when it comes to our health.
At this point, no public health organization in the U.S. —including the National Cancer Institute, the American Heart Association and the American Dietetics—has created recommended daily intake goals for soy foods. In 1995 in Japan, with all soy food products taken into account, the average intake was 50-70 total grams per day (not grams of soy protein, but of the entire food), which would translate into approximately 2 ounces per day. This is less than the amount ordinarily used in the United States with respect to a single serving of soymilk and the amount of tofu in a stir-fry.
From an ecological standpoint, there are concerns about soybeans that are produced in a non "eco-friendly" way — including soybean production that involves destruction of millions of acres of tropical forest or savannah in South America. Although organically grown soybeans are not required to be produced in a sustainable manner, many organic growers do use sustainable methods, and I support those methods as a way of helping to ensure nourishing foods for generations to come.
Together with corn, soybeans are one of the most widely engineered food crops from a genetic standpoint. In the United States, over 90% of all soybeans produced have been genetically engineered in some way (usually for herbicide tolerance). Since certification of foods as organic is still prohibited if the foods have been genetically engineered, purchase of organic soybeans and soy products is an effective way to avoid consumption and promotion of genetically engineered beans.
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