The health benefits of whole grains may extend beyond the heart, according to a new study that links the foods to a lower risk of inflammatory conditions such as arthritis or asthma.

Researchers found that among nearly 42,000 postmenopausal women, those who ate the most whole grains were about one-third less likely to die of an inflammatory disorder over a 15-year study period.

Inflammatory illnesses include any condition that involves chronic inflammation in body tissue; such inflammation is believed to contribute to a range of disorders, including heart disease, diabetes, musculoskeletal disorders like rheumatoid arthritis, respiratory illnesses such as asthma and digestive diseases like colitis.

Numerous studies have linked fiber-rich whole grains to a lower risk of heart disease and diabetes. The new findings now suggest they also protect against other inflammation-related diseases, the study authors report in the American Journal of Clinical Nutrition.

"The observed health effects are broader than heart disease and broader than diabetes," lead study author Dr. David R. Jacobs, Jr., of the University of Minnesota in Minneapolis, told Reuters Health.

The protection, Jacobs and his colleagues speculate, may come from antioxidant substances in whole grains that protect cells against the damaging effects of chronic inflammation.

The researchers based their findings on data from the Iowa Women's Health Study, which followed the health of 41,836 women ages 55 to 69 from 1986 through 2001.

Among other lifestyle assessments taken at the study's start, the women completed detailed questionnaires on their diets -- including how often they ate whole grains like oatmeal, brown rice, whole-grain breakfast cereal, bran, bulgur and popcorn.

Among those who ate 11 or more servings of whole grains per week, the odds of dying from an inflammatory condition during follow-up were about one-third lower than those of women who rarely ate whole grains.

Lower risks were also seen among women who ate at least four whole-grain servings a week.

Whole grains differ from refined grains, like white bread and snack foods made from white flour, in that they retain more of the fiber- and nutrient-dense components of the grain.

In an earlier study that analyzed the antioxidant capacity of more than 1,000 foods, Jacobs and his colleagues found that several whole-grain products were at the top of the list.

"I personally think that the public would do well to incorporate more whole-grain foods of any type into their diets," Jacobs said.