Consumers today are inundated with ads for so-called "functional foods" that will supposedly improve their health. But scientists and physicians associated with the American Council on Science and Health (ACSH) find that many of the supposed health benefits of these foods are not backed by substantial scientific information.
"It would be very helpful," notes ACSH president Dr. Elizabeth Whelan, "if we really could prevent prostate cancer, macular degeneration, or other health problems simply by including certain foods in our diets. But in most cases, the science behind such an approach isn't very strong yet, and in other cases there is no scientific evidence at all."
In a new report, Facts About "Functional Foods," experts evaluate the scientific evidence for a variety of health effects and rank them according to the strength of the evidence. The booklet is based on an extensive review of the scientific evidence by Dr. Clare Hasler, who was the Founding Director of the Functional Foods for Health Program at the University of Illinois at Urbana-Champaign.
The ACSH study separated the scientifically-supported claims of functional foods from the unfounded ones. For example, the evidence relating soy protein consumption to lower cholesterol levels is considered very strong. In contrast, evidence that links green tea to a reduced risk of some types of cancer is only weak to moderate.
In addition to classifying the strength of supporting data for various foods or food components, the booklet informs consumers about the differences in the various types of health statements they may come across in advertising or on food labels. For example, the federal Food and Drug Administration (FDA) has approved only 13 health claims for foods or food ingredients. To achieve this approval, there must be substantial scientific data to support the claim, and the FDA will typically specify how the claim may be stated.
"It is important for consumers to realize that the scientific data underlying statements on various food packages are not equally reliable," stated Dr. Ruth Kava, ACSH nutrition director. "Also, even those functional foods with solid scientific support should be consumed as part of a varied, proper diet if they are to be effective," she concluded.