The Food and Drug Administration said yesterday it will allow food manufacturers to label certain foods containing oats as being part of a diet that "may" reduce the risk of heart disease.

Although the agency has allowed previous "health claims" for categories or classes of foods, yesterday's decision marks the first time companies will be able to name a specific food in the claim.

The FDA's decision brings to an end, symbolically at least, a nearly 20-year-long saga in which oat bran became the first common food touted to have disease-preventing properties.

Specifically, many dietitians and health food advocates said that eating oats -- which contain a high proportion of largely indigestible fiber -- could lower bloodstream cholesterol. That, in turn, could reduce a person's risk of coronary heart disease, the proponents said.

Dozens of scientific studies investigated the claims. Many found specific benefit from oat bran, while others suggested that oat-eaters had lower cholesterol because they also ate less fat. In recent years, however, the medical evidence has clearly pointed to a specific -- if undramatic -- effect from the fiber in oats.

Quaker Oats Co. sought permission to make the health claim under the 1990 Nutrition Labeling and Education Act of 1990.

Scientists at FDA, aided by colleagues at National Institutes of Health and the Centers for Disease Control and Prevention, reviewed 37 studies before making their decision. Quaker Oats funded about one-third of the studies, which were performed by university and company scientists over the past 15 years.

Quaker Oats currently mentions the cholesterol-lowering effects of oats in print advertisements -- a medium regulated by the Federal Trade Commission. Yesterday's decision addresses only what it can put on food labels, which is a province of print that falls solely in FDA's jurisdiction.

Companies will not be able to say that oat products prevent heart attacks. Instead, the health claim must be made in a "dietary context," the FDA officials said. The agency gave two examples of what it considered acceptable:

"Soluble fiber from foods such as oat bran, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease," and "Diets low in saturated fat and cholesterol that include soluble fiber from oatmeal may reduce the risk of heart disease."

One nutrition activist organization, however, criticized the decision precisely because it believes the dietary context -- not the oats -- is the truly important message for consumers.

"The FDA's approved claim for soluble fiber from oats gives consumers the wrong message," said Bruce Silverglade of the Center for Science in the Public Interest. "Lots of fruits and vegetables, ranging from artichokes to beans, are good sources of soluble fiber, and all such foods, not just oats, can reduce the risk of heart disease when eaten as part of a diet low in saturated fat and cholesterol."

The decision will allow Quaker Oats and other companies "to specifically highlight the benefits of eating oats, when eating fruits and vegetables and other grain products can provide the same benefit."

A spokeswoman for manufacturers of vitamins and other dietary supplements, however, praised the decision.

"We are pleased and encouraged by this because it shows a willingness on FDA's part to approve new claims," said Annette Dickinson, of the Council for Responsible Nutrition.

The FDA has approved 10 other health claims for foods. For example, makers of low-sodium foods are allowed to say that low-sodium diets may lower the risk of hypertension. The labels of some dairy products can say the substances are high in calcium, and that diets high in calcium can help prevent osteoporosis. Foods high in folate can mention that adequate intake of folate by women on child-bearing age can reduce the rate of birth defects.

Artificial sweeteners in chewing gum are the foods with the longest-standing claims to a disease-preventing effect. Since the 1970s, gum makers have said on their packages that "sugarless" gum reduces the risk of developing tooth decay, at least when compared to gum that contains sugar. After the 1990 law took effect, those companies were told to submit data supporting the claim, and they have, Edward Scarbrough, director of FDA's office of food labeling, said yesterday.

To make a health claim for oats, a product must contain enough of the grain that consumption of it regularly would reasonably be expected to lower a person's cholesterol. Specifically, a serving of oat-based food must contain 0.75 grams of the soluble fiber beta-glucan.

The FDA considers that people have four "eating opportunities" a day -- three meals and one snack. If a person were to eat an oat product with that amount of soluble fiber at each of those, he or she would consume 3 grams a day. "Three grams is sort of the threshold -- from the clinical studies that were submitted -- that we thought produced a statistically significant effect," said Scarbrough. "That is not to say that less than that has no effect."