VAS-COG: Exercise in Midlife May Protect the Aging Brain

SAN ANTONIO, July 16 -- Regular physical activity during midlife is linked to a reduced risk of brain infarcts years later, particularly in men, study shows.

Older men who had exercised or played sports in their 40s and 50s had more than a 50% reduction in the risk of cortical and subcortical brain infarcts, according to data presented here at the International Society for Vascular Behavioral and Cognitive Disorders meeting.

Older women also tended to benefit from midlife physical activity, but not significantly so, said Satu Pajala, Ph.D., of the National Institue on Aging, and colleagues.

Their findings came from the longitudinal, population-based Reykjavik Study begun in Iceland 40 years ago, with a follow-up investigation in 2002.

In the earlier study, participants (whose mean age was about 50 at the time) were asked whether they had engaged in sports or exercised regularly since age 20. The follow-up study included a full-brain MRI evaluation.

For the current analysis men and women who reported one or more hours of physical activity a week in the 1967 study were classified as exercisers, and those who were less active were classified as non-exercisers. Complete data from both studies were available for 1,956 participants, whose mean age was about 76.

Overall, 33% of the 818 men and 22.1% of the 1,138 women had MRI evidence of infarct-like brain lesions.

Among men, 26% of infarcts were subcortical, 26% were cortical, and 48% were cerebellar. In women the distribution of infarcts was 21% subcortical, 19% cortical, and 60% cerebellar.

Men who had been physically active earlier in life had about a 50% reduction in the risk of subcortical infarcts and a 60% to 70% reduction in the risk of cortical infarcts compared with men who had been inactive.

Physically active women had about a 20% to 25% reduction in risk for subcortical infarcts and a 50% risk reduction for cortical infarcts. Physical activity had no apparent effect on late-life white-matter lesions in men or women.

After adjustment for multiple clinical and demographic variables, physically active men had an odds ratio of 0.67 (95%CI 0.40- 0.99) for subcortical infarcts and 0.71 (95% CI 0.50-1.00 for all infarcts)for all infarcts compared with men who reported a sedentary history.

Among women the odds ratios for subcortical (OR 1.07 (95% CI 0.64-1.78) and total infarcts OR 0.97 (CI .70-1.34) did not differ between active and inactive study participants.

"On the basis of these findings, we hypothesize that exercise in earlier life may be important in maintaining brain health in old age and that exercise's effect on the brain is rather focal than diffuse," Dr. Pajala concluded.