Physical activity and the risk of dementia in oldest old

Objective: This study evaluated the protective role of physical activity (PA) against cognitive impairment (CI) in the oldest old (age ≥ 85). Method: Prospective data on 66 optimally healthy, oldest old adults (mean age 88.5) were analyzed using survival analysis. Results: In all, 12 men and 11 women reported exercising > 4 hours per week, and 38 participants developed CI (mean onset age 93; mean follow-up 4.7 years). The effect of exercise was modified by gender. In more active women (> 4 hours/week), the risk of CI was reduced by 88% (95% confidence interval 0.03, 0.41) compared to those less active. Less active women had 2 times the incidence rate of CI compared to less active men and almost 5 times the rate compared to active women. Discussion: This study demonstrates the beneficial effects of exercise on healthy brain aging even in the oldest old and emphasizes the importance of increasing PA in older women.