-- Daily intake of antioxidants, such as vitamins C and E, could help asthmatics breathe easier, experts say.

"Supplementation of the diet with vitamins E and C benefits asthmatic adults," according to a study from the Department of Environmental Health at the University of Washington in Seattle.

Antioxidants &e a class of chemicals that neutralize 'free radicals' -- compounds in the body which can produce oxidation-based cellular damage. Such damage has already been linked to various diseases, from heart disease to cancer.

Study lead author, Dr. Carol Trenga, suspected the power of antioxidants to fight free radicals might also be of benefit to those suffering from asthma.

"There's been a lot of evidence mounting over the last several years -- in fact, you can go back to the 1930s," she explained. "It was found that vitamin C seemed to help people with hyperactive airways. People with asthma of course have hyperactive airways, that's what an asthma attack is."

Trenga and her colleagues performed 'peak flow' lung function tests (measuring the amount of breath expelled by the lungs) on 17 asthmatics. The participants took the test while running on a treadmill and breathing in high levels of common airborne pollutants. Such pollutants can trigger or exacerbate asthmatic symptoms.

The study subjects whose diets were supplemented with daily dosages of 400 IU (international units) of vitamin E, and 500 mg of vitamin C, saw an 18% increase in peak flow capacity over those on 'regular' diets, according to the study. The study authors emphasize that that 18% increase occurred in those asthmatics suffering the 'most severe' symptoms.

Trenga labeled this a "very obvious improvement" in asthma symptoms.

She says it only makes sense that antioxidants would help asthmatics breathe easier. "We know that people with asthma have a lot of inflammation in their lungs which causes chronic oxidative stress, so they're already 'primed' if you will, for oxidative damage."

She says asthmatics may also have higher levels of free radicals than healthier individuals. And Trenga says, vitamins C and F have a particularly efficient partnership in cleaning up those compounds. "When vitamin E clenches a radical, it becomes a radical (itself) -- it doesn't cause damage but it is inactivated," she explained. But vitamin C seems to be able to reactivate vitamin E "so it can be used again."

Trenga believes the antioxidant vitamin levels found to be beneficial in the study can be easily obtained in daily diets. "I think if you eat very well, you can certainly achieve those levels of intake," Trenga said.

But could antioxidants ever replace regular anti-asthma medications? Trenga says flirther studies are needed. "We certainly can't say that yet," she said, "(But) my intuition tells me that if these vitamins are really helping (asthmatics) with their chronic inflammation, the logical deduction is that they're going to need at least less symptomatic intervention."

She believes "clinicians should really be paying attention to this sort of thing. Because anything an individual can do, by... altering their diet and taking modest levels of supplements to help reduce the need for medications, I think that's very exciting from a public health point of view.

Trenga presented her findings at this week's American Lung Association/American Thoracic Society International Conference in San Francisco.