Incidence of asthma has been climbing steadily in the Western world and is the most common long term condition in the UK today, according to the charity Asthma UK. It is thought that modern lifestyle, including pollution and hygiene, contributes to the risk of developing asthma, and diet could also play a role in this, believe some scientists.
Previous evidence that vitamin E may reduce asthma symptoms came from the Nurses Health Study, which found that those with a higher intake of vitamin E had fewer new diagnoses of asthma. There have also been some trials of vitamin E with other antioxidants, such as vitamin C, that suggested a benefit.
Some asthma patients do therefore take vitamins including vitamin E, despite the lack of evidence, said Dr Andrew Fogarty, lead researcher on the new study.
Dr Fogarty and colleagues at the University of Nottingham in the UK were the first to assess vitamin E (they used natural D-alpha-tocopherol ) on its own for benefit to asthma patients.
The scientists recruited 72 adults, aged 16-60 years old, with asthma. Half of the group received a daily 500g vitamin E supplement for six weeks, while the other half were given an identical placebo.
The results, reported in this month's issue of Thorax (vol 59, issue 8, pp652-6), showed no difference between those who had been taking vitamins and those who had been given placebos.
However Dr Fogarty told NutraIngredients.com: "This study does not exclude a potential benefit for vitamin E as a therapy for asthma. We may have got the dose wrong, the duration of treatment wrong, or it may be that vitamin E has to be given with other antioxidants such as vitamin C to get a synergistic effect."
"This is an area of great potential, as if we can find a nutrient that influences asthma, then this will result in a new treatment approach for a common disease," he added.
Antioxidants are thought to help to protect the body's immune system. A recent study found that vitamin E protected elderly people from getting colds.