Health Options Alan Titchenal  & Joannie Dobbs                   Wednesday, December 22, 1999

Nutrition news met with distrust

Have you felt frustrated and confused by news reports on nutrition and health? Does the information seem to be changing all the time, leaving you unsure about what to do? If you answer yes, then you are not alone.

An article in the November issue of the American Journal of Clinical Nutrition indicates most of us are skeptical about information on food and health. More than 75 percent of primary household shoppers believe that within five years, "experts" will completely change their opinions about which foods promote health.

Three big questions come to mind: 1) Is nutrition science really that fickle? 2)Why can't nutritionists make up their minds? 3) While researchers are changing their minds, what is a consumer to do?

Actually, research is not fickle. Research results from one study are not considered conclusive by the scientific community. Remember, good research requires multiple studies to validate techniques and theories. It requires consider­able discussion by researchers about the interpretation of data. Only then can research data be considered reliable enough for making appropriate food choice recommendations.

Nutritionists agree with each other more than they disagree. However, the greatest disagreement comes from single study results presented at professional meetings and then presented to the public as if they were accepted by scientific peers. The field of health and nutrition is so large that few individuals have the time to read all of the literature pertaining to their area of study. Therefore their conclusions may be only one possible interpretation of data.

The reports on the association between tofu consumption and brain aging in Japanese men in Hawaii is a good example of this. Whereas this is a provocative observation and deserves further research for clarification, it does not justify putting tofu among "bad" foods. This data does justify refraining from taking concentrated soy isoflavone supplements until more research is done.

There are so many studies reporting that soy foods reduce the risk of heart disease that FDA recently authorized a health claim on soy food labels saying soy protein may help to reduce the risk of heart disease. In addition, a great deal of research indicates soy foods have anti-cancer effects and may help prevent the development of osteoporosis.

Dr. Lon White, the lead author on the Hawaii tofu study, is quick to point out that further research is needed to confirm and explain their observations. Their results do not indicate a "cause and effect" relationship. There could be many other differences between the men who ate more or less tofu. For example, it is possible that the men who consumed more tofu ate less meat, fish, and poultry, resulting in lower vitamin B-12 intake. Brain dysfunction related to vitamin B-12 deficiency is quite common among the elderly.

News reports on "contrary" studies attract interest. Media coverage for researchers can improve chances for research funding. Consequently, there is a tendency for reporters and researchers to overstate the relevance of a single study.

Our recommendation is to avoid reacting to reports on individual studies. Allow time for some consensus to develop before making radical changes in your eating habits. Take the advice of only those you trust. And trust only those who are truly knowledgeable.