June 18, 2003 -- (BRONX, NY) -- Seniors who devote their leisure time to cognitive activities such as reading appear to reduce their risk of developing Alzheimer's disease and vascular dementia, according to 21-year study conducted by researchers at the Albert Einstein College of Medicine of Yeshiva University.
The Einstein researchers, led by Dr. Joe Verghese, assistant professor of neurology, monitored a group of 469 men and women from 1980 to 2001. All the participants lived close to Einstein in the Bronx, were older than 75 and were screened at enrollment to rule out the presence of dementia.
Besides reading, the cognitive activities associated with a reduced risk for developing dementia included playing bridge, doing crossword puzzles, or playing a musical instrument. Dancing was also beneficial, although physical activity in general did not affect dementia risk in this study.
For each beneficial activity, the risk reduction was related to how often it was performed: Seniors who did crossword puzzles four days a week, for example, had a risk for dementia that was 47 percent lower than for seniors who did puzzles only once a week. Overall, participants who were in the upper third on the cognitive-activity scale had a 63 percent lower risk of developing dementia compared with those whose scores were in the lowest third.
"We looked at the subjects' leisure activities upon their enrollment in the study and developed an 'activity-days per week' scale reflecting how often they engaged in cognitive and physical activities each week," explains Dr. Verghese. "While 124 people did develop dementia over the 21 years of the study, higher cognitive-activity scores were significantly associated with reduced risk for dementia for both Alzheimer's disease and vascular dementia."
The Einstein findings confirm previous, shorter-term observational studies suggesting that active participation in leisure activities help protect against dementia. But since a long period of cognitive decline often precedes a diagnosis of dementia, it was not clear from those earlier studies whether reduced participation in activities is a cause of dementia or merely a consequence of it. Thanks to its unusually long duration, the Einstein study was better able to address this issue.
Previous research at Einstein had shown that memory begins declining rapidly seven years before people are diagnosed with dementia. So Dr. Verghese and his colleagues eliminated from analysis all those individuals-a total of 94 people--who developed dementia during the first seven years of the study. Even when those people with preclinical dementia were excluded, the association between cognitive-activity score and risk for dementia was still significant.
The researchers also controlled for other factors that might have confounded their results. "Conceivably, protection from dementia in our study was really due to being smarter and better educated, and people with those attributes were simply more likely to engage in cognitively stimulating activities," notes Dr. Verghese. "But adjusting the data for intelligence and educational level didn't weaken our results. Plus, when we restricted our analysis to individuals with a high school education or less, the association between cognitive-stimulating activities and reduced risk of dementia was maintained."