This finely ground flour is made from soybeans and, unlike many flours, is very high in protein (twice that of wheat flour) and low in carbohydrates. Soy flour is ordinarily mixed with other flours rather than being used alone. It has a wide variety of uses such as for baking and to bind sauces. In Japan, it's very popular for making confections. Soy flour is sold in health-food stores--sometimes under the name kinako--and in some supermarkets. Although soyfoods are widely recognized for their nutritional qualities, interest in soyfoods has risen recently because scientists have discovered that a soy component called isoflavones appears to reduce the risk of cancer. More research needs to be done to determine exactly how isoflavones work, but it appears that as little as one serving of soyfoods a day may be enough to obtain the benefits of this anticancer phytochemical. Traditional soy products such as tofu, tempeh, and soy milk are very high in protein. Tempeh has the highest percentage of protein of the traditional soy products providing approximately 22 grams of protein for each 4 ounce (113 gram) serving. Tofu provides approximately 9 grams of protein for a similar small serving size. The Recommended Dietary Allowance of protein for adult males (aged 25-50) is appoximately 63 grams and 50 grams for adult females (aged 25-50). Soy products can provide a significant portion of one's daily protein needs. It is important to keep in mind, however, that the balance of amino acids (protein building blocks) in soy is not the same as meat. Because soy foods does not have an ideal balance of amino acids, some experts recommend taking in a little extra soy foods and/or combining soy products or legumes with a whole grain dish at meals where other protein (e.g., eggs, fish) is not eaten. The amino acids in whole grains combine well with amino acids in soy and legumes to make a more ideal balance of amino acids. If a person's diet is reasonably-balanced, however, there is usually no need to be concerned about getting enough protein.
Vegetarians and health enthusiasts have known for years that foods rich in soy protein offer a good alternative to meat, poultry, and other animal-based products. As consumers have pursued healthier lifestyles in recent years, consumption of soy foods has risen steadily, bolstered by scientific studies showing health benefits from these products. Last October, the Food and Drug Administration gave food manufacturers permission to put labels on products high in soy protein indicating that these foods may help lower heart disease risk. As with health claims for oat bran and other foods before it, this health claim provides consumers with solid scientific information about the benefits of soy protein and helps them make informed choices to create a "heart healthy" diet. Health claims encourage food manufacturers to make more healthful products. With soy, food manufacturers have responded with a cornucopia of soy-based wares. (See "The Soy Health Claim.") No sooner had FDA proposed the health claim regulation, however, than concerns arose about certain components in soy products, particularly isoflavones. Resulting questions have engulfed the regulation in controversy. This came as no surprise to Elizabeth A. Yetley, Ph.D., lead scientist for nutrition at FDA's Center for Food Safety and Applied Nutrition . "Every dietary health claim that has ever been published has had controversy," she says, "even the relationship of saturated fat to a healthy diet." While the controversy may seem confusing to the consumer giving it casual consideration, a careful review of the science behind the rule reveals a strict divide between what FDA allows as a health claim based on solid scientific research and related issues that go well beyond the approved statements about health benefits of soy protein.