Evaluating Food Supplement Safety

The food supplement industry is on track to reach $20 billion in sales in the not-so-distant future. Such explosive growth is not surprising—several national opinion surveys indicate that substantial numbers of Americans regularly take dietary supplements. A recent article indicated that many supplement users felt so strongly about their needs for certain supplements that they would continue to use them regardless of any evidence to the contrary. However, it also indicated that consumers supported government regulation and believed that the Food and Drug Administration should have increased authority to remove unsafe products.

The 1994 Dietary Supplement Health and Education Act freed supplement manufacturers from many FDA regulations resulting from the Nutrition Labeling and Education Act of 1990. The burden of proof concerning the safety of dietary supplements shifted from the manufacturer’s having to show that a supplement was safe, to FDA’s having to prove that it was unsafe. Issues of supplement efficacy were swept under labeling, where general health claims are permitted as long as no reference is made about preventing or curing specific diseases. Dietary supplements are to be considered equivalent to foods in that  they are assumed safe unless FDA has evidence that proves otherwise.

Following a series of meetings and workshops with stakeholders and other interested consumers, FDA ascertained that it will need an efficient and  scientifically sound approach for safety consideration of dietary supplements. A National Academy of Sciences committee, recognizing that the diversity of supplement products presents an enormous task, developed a three-tier framework for evaluating the safety of dietary supplement ingredients:

1. An initial screening and flagging process, using readily available information to flag substances that warrant further attention.

2. A priority-setting process, in which additional factors are considered, additional information is obtained, strength of evidence for efficacy and harm is judged, and information is weighed on the basis of importance. Six diverse dietary supplements ingredients have been identified as priorities for test studies (see www.nap.edu/catalog/10456.html for details).

3. A critical safety evaluation process, resulting in safety monographs. To date, monographs have been posted on chaparral and shark cartilage.

FDA’s efforts in undertaking the mammoth task of evaluating the safety of dietary supplement ingredients should be applauded. However, as the agency moves forward, it should include certain actions in its deliberations. It should:
• Provide access to international regulatory databases on supplements. It would be useful to easily access the scientific information acquired by other countries on bans and limitation of supplements. Some supplements have been regulated in some countries more than in the U.S. The question is whether they are more knowledgeable about the safety or are reacting to other factors. Such information should be more easily available, so both industry and consumers can better understand the differences in regulatory action.

• Sponsor task forces for the study of supplements prioritized for safety concerns. This may be a useful adjuvant to the last step of the three-tier approach. Scientists and stakeholders would have an opportunity to voice concerns and achieve concurrence on issues of disagreement.

• Recognize that some individuals may be more sensitive or prone to adverse effects, while others may derive health benefits. It is likely that for any given supplement, we will find a subpopulation who, because of various traits, genetic makeup, immunological sensitivities, or other underlying environmental factors, will have an adverse effect. It is important to identify such groups and the conditions that make them vulnerable. However, it is equally important to be aware of which populations may derive benefits from a given supplement. In other words, we should not necessarily make blanket bans, such as banning saccharin in spite of its usefulness to the diabetic population.

• Provide informative materials to physicians and health-care workers about adverse supplement interactions with drugs and foods. A recent survey indicated that supplement users do not involve their physicians because they believe that physicians know little or nothing about such products. Also, one out of six parents reported giving such supplements to children; this emphasizes the need to have health-care workers in the loop.

by STANLEY T. OMAYE
Contributing Editor
Professor, Dept. of Nutrition and
the Environmental Sciences & Health Program
University of Nevada, Reno