- Effect of vitamin E on pneumonia studied
- Vitamin E prevents pneumonia risk in elderly men who exercised and are non-smokers
- Vitamin E didn’t have any effect on elderly men who smoked heavily and had not been exercising.
Intake of vitamin E supplements increases the risk of pneumonia for more than one in four older men (28%) who smoked and did not exercise, finds study published in the British Journal of Nutrition.
However, the opposite effect was true for older men who exercised and did not smoke - in that vitamin E actually decreased their risk of contracting pneumonia.
The findings of the study focussed on men aged 50 to 69 years old at the baseline of the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study - ATBC trial conducted in Finland between 1985 and 1993. There were 898 cases of pneumonia among 29,133 participants of the study.
Dr. Harri Hemilä of the University of Helsinki, Finland - discovered that vitamin E effect on health outcomes may depend on various characteristics of people and their lifestyles. Dr. Hemilä concluded that nearly all variation in the vitamin E effect on pneumonia risk over five subgroups was explained by true differences in the vitamin E effect rather than by chance variation.
Vitamin E increased risk of pneumonia by 68% among older men who smoked heavily and who did not exercise.
Vitamin E decreased pneumonia risk by 69% among older men who had least exposure to smoking and exercised.
The high level of true heterogeneity in the vitamin E effect on pneumonia has important implications:
First, it provides a strong argument against the opinion that subgroup analyses of randomised trials should be strongly discouraged because they can lead to false positive findings due to the multiple comparison problem.
Second, the average effects of vitamin E that are calculated in meta-analyses may not be valid for many population groups.
Third, in cohort studies, confounders are adjusted to allow the calculation of a single estimate of effect over the study population.
The lead author suggests that vitamin E should not be suggested for the general population for improving the immune system.
There is a need for further research on vitamin E for non-smoking elderly men who exercise in their leisure time.