Six weeks of dietary supplementation with vitamin E adds no benefit to the standard treatment of mild-to-moderate asthma in adults, according to researchers in the UK.

“Increased dietary vitamin E intake is associated with a reduced incidence of asthma, Dr. Andrew Fogarty and colleagues from Nottingham City Hospital note in the August issue of Thorax. In addition, combinations of antioxidant supplements that contain vitamin E have been effective in reducing bronchoconstriction induced by ozone.

This prompted the team to examine the effect of 500 mg/day natural vitamin E versus placebo (sugar pill) on asthma symptoms in 72 adults with mild to moderate asthma. The subjects continued to receive at least one dose of inhaled corticosteroid per day.

The main outcome measures were changes respiratory capacity, symptom scores, bronchodilator use, and serum immunoglobulin E levels.

No significant differences were observed between the vitamin E and placebo groups after 6 weeks.

“Since we have previously found a similar outcome for vitamin C and magnesium supplements in asthma, our trials indicate that these single nutrients are not effective,” Fogarty and colleagues comment.

“Future studies of antioxidants should therefore perhaps consider using combinations of antioxidants, whether in a synthetic preparation or in the form of whole food such as fruits.”

Thorax, August 2004.