A retrospective analysis (1) of the wide-ranging Alpha Tocopherol Beta-Carotene (ATBC) Cancer Prevention study has shown that alpha tocopherol (vitamin E) appears to offer substantial protection to elderly males who smoke at a low level (5-19 cigarettes a day) and who exercise moderately.
The ATBC study took place in Finland between 1985-1993 and examined the effects of both vitamin E and beta-carotene in a large cohort of elderly male smokers (n=22,657) with regard to a wide range of clinical end points. The results indicated that vitamin E may have a benefit in preventing lower respiratory tract infections, specifically pneumonia. The new paper looks at a sub-group of the original study population (n=7,469), which consists of individuals who were defined as light smokers (5-19 cigarettes a day), who exercised daily and who did not start their smoking habit until they had reached a minimum age of 21 years. This group had been selected by the author as having the best chance of obtaining a clinical benefit from the intervention.
Advancing age is a major risk factor for the onset of pneumonia. The risk of onset is exasperated by smoking and lack of exercise.
The participants of the ATBC study received a daily intervention of 50 mg DL alpha tocopheryl acetate for a period of five to eight years. The intervention results in an average increase in terms of the participants vitamin E blood serum levels of ca. 50 percent.
Thirty-five percent of the light smoker elderly male sub-group who exercised experienced a reduction in the incidence of pneumonia due to the vitamin E intervention. One in 12.5 of these participants benefited from the intervention. However, the levels of benefit were much lower (or even non-existent) in individuals who were either heavy smokers (more than 20 cigarettes per day), started smoking before the age of 21 years or who did not exercise. The benefits appeared to increase with age, such that by the age of 74 years, the light smoking male participants in the vitamin E intervention group had a cumulative risk of pneumonia (6.7 percent) as opposed to 19.6 percent in the placebo group. A previous analysis of data from the ATBC study demonstrated that vitamin E was protective against the onset of the common cold in those aged 65 years or older.
Care has to be taken in interpretation of the ATBC study. It is not known if the benefits achieved by the vitamin E intervention would be seen in other populations e.g. in other geographical areas, young people, females or non-smokers. As an example, a much smaller study of healthy individuals aged 60 years or older in Northern Holland (3) who received a pharmacological dose of vitamin E of 200 mg a day did not achieve any protection against respiratory tract infections. However, two years later, another small study (4) of elderly nursing home residents in Boston MA with a 200 IU/day vitamin E supplementation showed benefits in prevention in the onset of upper respiratory tract infections, but no effect was seen on lower respiratory tract infections.
In summary, the new paper (1) appears to demonstrate, in a specific population, a protective effect of vitamin E against the onset pneumonia in elderly males who have a compromised health status due to smoking. However, the benefit is lost in heavy smoking and immobile individuals.