According to the World Health Organization, Mexico City has some of the worst air quality in the world. So two local hospitals were motivated to research alternatives to help alleviate asthma symptoms in young children, focusing on how antioxidants may influence the inflammatory response to ozone, a pollutant found in smog.

At the Hospital Infantil de Mexico, researchers conducted a randomized, double-blind trial with 117 children with asthma. The children were given either a daily supplement of antioxidant vitamins (50 mg of vitamin E and 250 mg of vitamin C) or a placebo, and observed for four months. Nasal lavages were performed three times during the trial and analyzed. After reviewing the results, the researchers concluded that vitamin C and E supplementation, above the minimum dietary requirement, might provide some protection against acute nasal inflammatory response to ozone in asthmatic children with a low intake of vitamin E.

At the Instituto Nacional de Salud Publica, lung function among children with asthma was also improved with antioxidants. In this study, 158 children with asthma were given either a daily supplement of antioxidant vitamins (50 mg of vitamin E and 250 mg of vitamin C) or a placebo, and were followed for 18 months. Pulmonary function tests were carried out twice a week in the morning.

The researchers reported significant differences in lung function between groups, and said, “our results suggest that supplementation with antioxidants might modulate the impact of ozone exposure on the small airways of children with moderate to severe asthma.”

Sources: Clin Exp Immunol. 2004 Nov;138(2):317-22; Am J Respir Crit Care Med. 2002 Sep 1;166(5):703-9