A US federal inter-agency group should develop and implement an integrated risk-management strategy and action plan to reduce human exposure to dioxins in foods, says a new report from the Institute of Medicine of the National Academies. Government officials should collaborate with the private sector to identify and pursue voluntary interventions to further minimize levels of these toxic compounds in human foods and animal feeds. However, the health risks posed by the levels of dioxins in foods have yet to be ascertained, so the report does not recommend regulatory limits on dioxins or dioxin-like compounds (DLCs) in food or feed.
Since fetuses and infants are especially sensitive to the effects of toxic compounds, one part of the government's action plan should be an effort to reduce girls' and women's exposure to dioxins in foods during the years well before childbearing, so that less of these compounds accumulate in their bodies and are passed on through the placenta and breast milk, the report adds. By promoting compliance with current dietary recommendations to consume less animal fat -- where dioxins primarily collect -- the government could help all Americans reduce their exposure to these compounds.
"Because the risks posed by the amount of dioxins found in foods have yet to be determined, we are recommending simple, prudent steps to further reduce dioxin exposure while data are gathered that will clarify the risks, " said Robert Lawrence, associate dean for professional practice and programs, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, and chair of the committee that wrote the report.
Dioxins and DLCs are long-lasting compounds that accumulate in the body fat of animals and people. Although dioxins are ubiquitous in the environment, the fats in meat, poultry, fatty fish, whole milk, and full-fat dairy products are the principal source of most people's exposure. However, fetal and infant exposure depends on the amount in the mother's body because these compounds can cross the placenta and also collect in the fat in breast milk.
High levels of dioxins have been linked to endocrine-related conditions, developmental problems, and susceptibility to cancer, among other health hazards. However, more research is needed to discern whether small amounts of dioxins are toxic and at what levels they begin to pose risks. Further improvements in analytical tools and methods will enable researchers to better characterize any possible risks associated with low-level exposure. Dioxin levels in the environment have declined dramatically in recent decades -- by as much as 76 percent since the 1970s, according to some measurements. Dioxin levels in foods have decreased greatly as well.
The committee was not asked to offer any judgments about the risks of human exposure through foods, but rather to recommend risk-management options that would further reduce dioxin exposure among the general population and vulnerable groups until the health risks are defined. The report recommended no mandatory limits on dioxins, given the current lack of precise data on both the risks and the current amounts of the compounds in foods and feeds.
Minimizing girls' and young women's intake of dioxins during the years before pregnancy is the only practical way to reduce dioxin exposure in fetuses and breast-feeding infants, the report says. Given the health and social benefits of breast-feeding, the committee recommended strategies to reduce accumulated body levels of dioxin, rather than to discourage breast-feeding.
To reduce dioxin exposures in all children -- especially girls -- government-sponsored food programs, such as the National School Lunch Program, should increase the availability of foods low in animal fat. For example, low-fat milk should be made more widely available in the school lunch program. Also, the U.S. Department of Agriculture should analyze the impact of setting limits on the amount of saturated fat that can be present in meals served in the school breakfast and lunch programs. Except for children under age 2, participants in the Special Supplemental Food Program for Women, Infants, and Children should be encouraged to choose low-fat milk and foods.
Promoting compliance with the Dietary Guidelines for Americans on consumption of saturated fats and fats in general would minimize people's dioxin exposure without compromising their intake of nutrients.
Because of the health benefits associated with omega-3 fatty acids in fish and the difficulty of trimming fat from fish, the committee did not recommend that people reduce their consumption of fatty fish below the currently recommended two servings per week.
The committee also urged the government to give priority to reducing dioxin contamination of animal feed, and to curtailing the recycling of dioxins that occurs when contaminated grass forage and animal fat are included as ingredients in feed. Federal agencies should work with food producers to develop voluntary guidelines for animal feeding and food-production practices that would minimize animals' exposure to dioxins.
The report was sponsored by the U. S. Department of Health and Human Services, Food and Drug Administration, and agencies within the U. S. Department of Agriculture. The Institute of Medicine is a private, nonprofit institution that provides health policy advice under a congressional charter granted to the National Academy of Sciences.
Copies of Dioxins and Dioxin-like Compounds in the Food Supply: Strategies to Decrease Exposure will be available later this year on the Internet at: http://www.nap.edu.
