Preschoolers whose families get federal food aid have much healthier diets than low-income children whose families are not getting assistance. And federally aided children are protected from iron and zinc deficiencies, according to a new Cornell study.

What's more, the study shows, the benefits to the young children from direct food aid are much greater than if the families are given a cash allowance.

Specifically, the researchers found that preschoolers in the WIC program (the Special Supplemental Nutrition Program for Women, Infants and Children) received 17 percent more of the recommended daily allowance, or RDA, for iron than nonparticipating low-income children and 10 percent more of the RDA for zinc in their diets, as well as significant boosts of eight out of 13 other nutrients studied. These benefits were realized without increases in fat, saturated fat or cholesterol.

Preschoolers whose families receive food stamps from the U.S. Department of Agriculture (USDA) also benefit significantly, although the effects are not as dramatic, noted Jean-Pierre Habicht, M.D., the James J. Jamison Professor of Nutritional Epidemiology at Cornell, writing in the March issue of Journal of Nutrition, the journal of the American Society for Nutritional Sciences.

Habicht and his colleagues, Donald Rose of the USDA Economic Research Service and Barbara Devaney of Mathematica Policy Research, Princeton, N.J., studied 499 low-income preschoolers. The children were either enrolled in the WIC program, which also is administered by the USDA, in the food stamp program, in both or in neither.

"The iron and zinc benefits from these programs are particularly important because iron deficiency is the single most prevalent nutritional deficiency in the U.S., with up to 20 percent of low-income preschoolers under 2 years of age suffering from anemia," Habicht says.

"Zinc is also particularly important because other studies suggest that zinc deficiencies are related to growth retardation," he says.

In the article, the researchers noted that iron and zinc levels were well below the RDA in the studied preschoolers not receiving federal food assistance, but iron intake was well above the RDA in the children in the WIC program; iron and zinc levels also significantly improved in children receiving food stamps.

Although previous studies have looked at the benefits of the WIC program for pregnant women and the effects of food stamps on household diets, few studies have evaluated the effect of either program on nutrition, particularly in preschoolers. Yet, about half of the participants in the WIC program are preschoolers.

Such evaluations are important not only for the growth and general well-being of young children but also because the USDA's food assistance programs cost $37.8 billion in 1995. Also, the recent debate on welfare reform has prompted the need to assess the effects of the federal food assistance programs, Habicht says.

The researchers analyzed the amounts of 15 nutrients consumed over three days by participating and nonparticipating low-income children. The intake of 10 of the nutrients (vitamins A, E and B6, thiamin, riboflavin, niacin, folate, magnesium, iron and zinc was significantly improved for children in the WIC program, and improved for five of the nutrients (iron, zinc, vitamin A, thiamin and niacin) for children in the Food Stamp Program.

Habicht says the results show that household participation in the food stamp and WIC programs had "significantly positive effects" on the nutrient intake of preschoolers. The report concluded: "The beneficial effects, especially of the WIC program, on iron and zinc intakes are not only significant in public health terms but are also much greater than what would have been achieved with increases in cash income. It is also important to note that these benefits come without the potentially deleterious effects of increases in the intake of fat, saturated fat and cholesterol."

The study was funded in part by the USDA.