Women searching for ways to ward off the anxiety and irritability caused by premenstrual syndrome may be able to find answers as nearby as their local supermarket.

A study published Monday finds that a diet rich in calcium and Vitamin D -- available in milk, cheese, yogurt and fortified orange juice -- appears to help women reduce the risk of PMS symptoms.

The findings support earlier research indicating calcium seems to help women cope with PMS. But the new study also suggests that when calcium is combined with enough vitamin D, it may help prevent PMS altogether.

"It seems that women who eat more foods high in calcium and vitamin D have less risk of experiencing PMS," said the study's lead author, Dr. Elizabeth Bertone-Johnson of the University of Massachusetts. "It's very exciting, and could end up being good news for many women out there."

She said, however, that the research is too preliminary to recommend diet changes for women in general and that more thorough studies are needed.

Researchers say women who ate four servings or more a day of a dairy product, including milk, were less likely to develop feelings of anxiety, loneliness, irritability, tearfulness and tension that characterize PMS.

Estimates are that 8 percent to 20 percent of women may have premenstrual syndrome.

The study compared the diets and supplement use over 10 years of 1,057 women, ages 27-44, who were diagnosed with PMS to 1,968 women who didn't have PMS. All the women were part of the large, long-running Nurses Health Study and answered food questionnaires and other health surveys in 1991, 1995 and 1999.

Bertone-Johnson said researchers were able to control for other factors that might affect PMS.

The study, which appears in Monday's Archives of Internal Medicine, was supported by a grant from GlaxoSmithKline, the manufacturer of calcium supplements, as well as grants from the National Cancer Institute, National Institutes of Health and the Department of Health and Human Services. A co-author, Adrianne Bendich, is an employee of GlaxoSmithKline, but the scientists said the company had no control over the study design or analysis.

Asthmatics prone to exercise-triggered attacks may want to cut back on salt in their diets, according to a new study.

The Indiana University research is the first to show that changing salt intake for just two weeks can alter airway inflammation, and the flow of oxygen into the bloodstream.

The study included 24 people with asthma and exercise-induced asthma. Some of the study volunteers were put on a low-salt diet of 1,446 milligrams of sodium per day for two weeks. Others were put on a high-salt diet of 9,873 milligrams of sodium per day, an amount that's typical for many American adults.

At the end of two weeks, the volunteers on the high-salt diet showed a dramatic decline in lung function after physical activity. Their forced expiratory volume in one second (FEV1) -- a standard measure of lung function -- taken 20 minutes after exercise dropped by 27.4 percent over the two weeks, compared with a 7.9 percent decline for those on the low-salt diet.

A decline of 10 percent or more in post-exercise FEV1 is considered abnormal.

"These findings show that modifying your diet has the potential to modify a disease state," study author and exercise physiologist Timothy Mickleborough said in a prepared statement.

High-salt diets have a number of physiological effects, including increased blood pressure and blood volume that can cause pulmonary swelling that, in turn, results in airway obstruction, Mickleborough explained.

The study volunteers on the high-salt diet also had higher levels of airway cells in their sputum. Airway cells have been linked to the development of asthma and EIA. The people on the high-salt diet also had more pro-inflammatory mediators, which can cause airway constriction.

The findings appear in the June issue of Medicine & Science in Sports & Exercise.