The Benefits of Soy Protein in Your Family’s Diet


Soy protein products can be good substitutes for animal products because, unlike some other beans, soy offers a “complete” protein profile. Soybeans contain all the amino acids essential to human nutrition, which must be supplied in the diet because they cannot be synthesized by the human body. Soy protein products can replace animal-based foods–which also have complete proteins but tend to contain more fat, especially saturated fat–without requiring major adjustments elsewhere in the diet.


While foreign cultures, especially Asians, have used soy extensively for centuries, countries like the United Kingdom and the United States have been a bit slower in moving dietary soy beyond a niche market status. In many countries, soybean is a huge cash crop, but the product is used largely as livestock feed.


With the increased emphasis on healthy diets, that may be changing. Sales of soy products are up and are projected to increase, due in part, say industry officials, to the fact that many governmental authorities in different countries have concluded that soy should in incorporated into a person’s diet.


To qualify for the claim that soy is a solid addition to a diet, most governmental agencies with oversight of dietary claims set a standard that foods must contain at least 6.25 grams of soy protein per serving and fit other criteria, such as being low in fat, cholesterol, and sodium. The claim is similar to others the agency has approved in recent years to indicate heart benefits, including claims for the cholesterol-lowering effects of soluble fiber in oat bran and psyllium seeds.


One of the studies, conducted over nine weeks at Wake Forest University Baptist Medical Center and reported in the Archives of Internal Medicine in 1999, found that soy protein can reduce plasma concentrations of total and LDL cholesterol but does not adversely affect levels of HDL, or “good” cholesterol, which at high levels has been associated with a reduction in heart disease risk. Another often-quoted study, published in the New England Journal of Medicine in 1995, examined 38 separate studies and concluded that soy protein can prompt “significant reductions” not only in total and LDL cholesterol, but also in triglycerides, another fat linked to health problems when present at elevated levels.


Other studies hint that soy may have benefits beyond fostering a healthy heart. At the Third International Symposium on the Role of Soy in Preventing and Treating Chronic Disease, held in late 1999, researchers presented data linking soy consumption to a reduced risk of several illnesses. Disorders as diverse as osteoporosis, prostate cancer, and colon cancer are under investigation.


Soy protein also is found in many “meat analog” products, such as soy sausages, burgers, franks, and cold cuts, as well as soy yogurts and cheese, all of which are intended as substitutes for their animal-based counterparts.