Soy Wars

On October 26, 1999, the FDA made the dramatic move of authorizing the use of health claims about the role of soy protein in reducing the risk of coronary heart disease on labeling of foods containing soy protein. They concluded that foods containing soy protein, as part of a healthy diet, may reduce the risk of coronary heart disease by lowering blood cholesterol levels. This was big news!

Coronary heart disease causes more deaths in the U.S. than any other disease. High total cholesterol levels and high levels of low density lipoprotein (LDL) cholesterol are both associated with a higher risk of coronary artery disease. The FDA made their bold statement in response to clinical trials proving that consumption of soy protein, compared with other proteins, can lower both total and LDL-cholesterol levels. It appears that we need 25 grams of soy protein daily in the diet to show a significant cholesterol lowering effect.

Not all soy-containing foods can carry the heart disease claim. They must also meet the requirements for low fat, low saturated fat, and low cholesterol content -- unless the foods are made with the whole soybean. These may also qualify for the health claim if they contain no fat in addition to that present in the whole soybean. The food must also contain at least 6.25 grams of soy protein per serving, so that it is reasonable to expect that people might get 25 grams a day (four such servings).

Following the FDA ruling, a wave of new soy products gathered momentum. Some scientific studies suggested that soy foods had the ability to strengthen the bones as well as the heart, and even to prevent cancer - along with many other health benefits. Soy, in some form or other, appeared as an ingredient in an enormous number of foods. Most of what is labeled vegetable oil in ingredient lists is actually soybean oil. Soy oil became the most widely used oil in the U.S., responsible for more than 75 percent of our total vegetable fats and oils intake. You would almost expect a backlash, fueled by people in businesses who saw soy proteins replacing animal proteins and soy oils replacing saturated animal fats.

Several soy-damning articles written by some people in the red meat/saturated fat movement have been widely circulated on the internet. . They claim that soy contains anti-nutrients and toxins that make nutrition worse, not better. They suggest that it has never been a staple food before modern America. They claim that soy causes rather than prevents cancer. Soy doesn't strengthen but shrinks the brain and causes Alzheimer's. Soy's naturally occurring phytoestrogens don't prevent heart disease, but cause a host of estrogen-related diseases. And soy foods are causing goiters and other thyroid problems. They call soy a public health disaster, and call for a return to animal fat and animal protein. Cholesterol is your best friend.

After my talk at the 2004 Green Fest in Washington D.C., well-meaning attendees pressed copies of these articles in my hand. They were most stirred up about the phytic acid in soy foods. They fervently cautioned me that only fermented forms of soy were safe. “High levels of phytic acid in soy reduce assimilation of calcium, magnesium, copper, iron and zinc. Phytic acid in soy is not neutralized by ordinary preparation methods such as soaking, sprouting and long, slow cooking.” Phytic acid can decrease mental function, because it, “blocks zinc absorption. Zinc is essential for proper functioning of the brain.” Their dire warnings are especially grave for vegetarians, “Vegetarians who consume tofu as a substitute for meat and dairy products risk severe protein and mineral deficiencies.”

It is true that soybeans are rich in these phytates. So are many other healthy plant foods, including whole grains, nuts, seeds, and a variety of beans, grains, nuts and seeds. It is true that these phytates change the way that our intestines absorb food. They can decrease the absorption of metals and other minerals. But for people eating a varied diet, this is a wonderful, protective mechanism - not a problem. And, far from being calcium, magnesium, copper, iron, or zinc deficient, vegetarians often have better mineral status than non-vegetarians. And those who get a couple of servings of soy a day may be the healthiest of all.

Alan Greene MD FAAP