CAN KEEPING MENTALLY ACTIVE PREVENT ALZHEIMER DISEASE AND OTHER DEMENTIAS?
(March 2004)

The Bronx New York Aging Study has been active for 21 years. Between 1980 and 1983, 469 subjects, average age 79 years, two-thirds of them women, were enrolled and their mental function tested. They were then followed to determine the frequency of occurrence of Alzheimer Disease or dementia due to reduced blood supply to the brain (vascular dementia). At enrollment, they were given a battery of tests to assess mental function. These were repeated multiple times during followup. One hundred twenty-four of the subjects (more than 25 percent of the entire group) developed Alzheimer’s, vascular dementia, or other types of dementia. The likelihood of developing any type of dementia was reduced by 69 to 74 percent among those who frequently played board games or a musical instrument. A reduction in risk of 35 percent was found among those reading frequently; and a 41 percent lesser risk was observed among those often doing crossword puzzles (though this was not statistically significant). Writing and participating in group discussions did not reduce the risk. Among physical activities, only frequent dancing reduced risk significantly (by 76 percent).

In general, the more time spent in leisure time activities that require active mental functioning, the less the risk of developing dementia.

The authors’ conclusion is intriguing, “participation in leisure activities is associated with a reduced risk of development of dementia. The reduction in risk is related to the frequency of participation. If confirmed, our results may support recommendations for participation in cognitive activities to lower the risk of dementia that parallel current recommendations of participation in physical activities to reduce the risk of cardiovascular diseases”.

Commentary: This is an interesting, but clearly a preliminary study. There are several reasons for caution in interpreting the results.

- Of the 124 cases of dementia, about one-half had Alzheimer’s. That is a relatively small sample.

- The results are said to be similar for those with Alzheimer’s and other dementias (especially reduction in blood supply to the brain). The authors did not apparently analyze individual activities separately for Alzheimer’s and other forms of dementia. It is somewhat surprising that the mental activities cited would have the same beneficial effects on both major forms of dementia (Alzheimer’s and dementia due to reduced blood supply).

- Despite the claim that mental, but not physical, activities reduced risk of dementia, dancing was perhaps the most effective single activity.



Although still preliminary, the study is quite interesting and the recommendation for persons as they age to keep both physically and mentally active makes a lot of sense; whether mental activities really reduce the risk of dementia will have to be seen. It is also likely that understanding the basic mechanisms underlying Alzheimer’s and creating strategies based on that knowledge will be far more critical in preventing the disease than mental or physical activities or, for that matter, dietary prescriptions or dietary supplements.

Verghese, J., et al. Leisure activities and the risk of dementia in the elderly. New England Journal of Medicine. Vol 348 (June 19) Pgs 2508-2516. 2003.