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Frequently Asked Soyfood Questions

 

Soy/Health

12. I read an article on the negative effects of soy on the brain. Can you tell me more?

Here is a response from the United Soybean Board regarding Dr. Lon White's research on tofu and brain function.

Recently, Dr. Lon White, a medical doctor and researcher, conducted a 30-year prospective study in Hawaii involving over 3,000 Japanese-American men. In this study, dietary data were collected and cognitive function observed. His findings suggest a link between increased tofu consumption and decreased cognitive abilities. Dr. White also observed a relationship between low brain weight and tofu consumption. Although Dr. White's findings are noteworthy and merit further study, they must be considered in their proper context. Consideration of the following information should help consumers put Dr. White's study in perspective.

Epidemiological studies do not show cause and effect

Epidemiological studies like Dr. White's do not show cause and effect but rather deal with the incidence, distribution, and control of disease in a population. Epidemiological findings are often refuted by clinical evidence. A classic example is a body of epidemiological studies suggesting that calcium intake may actually increase the risk of osteoporosis and bone fractures. In contrast, human studies conducted by the National Institutes of Health proved that calcium improves bone density and protects against osteoporosis. Calcium has since become universally recognized as a preventive agent for osteoporosis.

Typically, an epidemiological study involving a dietary component would generally record the intake of 50 to 100 foods. When collecting dietary data on his subjects, Dr. White considered 26 foods. In addition, Dr. White's method for recording tofu intake was not consistent throughout the study. He created new categories to consolidate the answers given in two different time periods. This type of inconsistency may have had an impact on how Dr. White's results were measured.

Dietary decisions should not be based on one epidemiological study

American consumers today are flooded with information regarding health and nutrition. On occasion, this information is generalized and publicized at the expense of the health and wellness of the general population. One of the most recent examples is the transformation of how we view fats and oils. Consumers have been inundated with the message that "fats are bad." Now health experts are emphasizing the importance of some types of fat, such as the unsaturated fats found in products like soybean oil. In the face of all the research that demonstrates the health-promoting properties of soy, it is not in the best interest of the public to draw conclusions from one study.

The Food and Drug Administration endorses soy as a healthy addition to the diet

In November 1998 the Food and Drug Administration (FDA) proposed a rule allowing a health claim that links the consumption of soy protein with a reduced risk of coronary heart disease. After reviewing more than 40 research studies, including Dr. White's, the FDA decided to approve a soy health claim in October 1999. FDA found that the evidence supporting the cholesterol-lowering effects of soy protein was comprehensive and strong and that other studies, including Dr. White's, were inconclusive and/or unconvincing. 

For more information on soy and its effect on human health go to TalkSoy, Soyfoods.com, and Stratsoy.