The study, by scientists at the Rush Alzheimer's Disease Center and Rush-Presbyterian-St. Luke's Medical Center in Chicago, IL, appearing in the February 13, 2002, Journal of the American Medical Association, found that more frequent participation in cognitively stimulating activities is associated with a reduced risk of Alzheimer's disease (AD). The research looked at everyday activities like reading books, newspapers or magazines, engaging in crosswords or card games, and going to museums among participants in the Religious Orders Study, an ongoing examination of aging among older Catholic nuns, priests, and brothers from several groups across the U.S. On a scale measuring cognitive activity -- with higher scores indicating more frequent activity -- a one-point increase in cognitive activity corresponded with a 33 percent reduction in the risk of AD.
The examination of cognitively stimulating activities and risk of AD was conducted by Robert S. Wilson, Ph.D., and colleagues at the Rush Alzheimer's Disease Center, including David A. Bennett, M.D., principal investigator for the Religious Orders Study, and Denis A. Evans, M.D., director of the National Institute on Aging (NIA)-supported Rush Alzheimer's Disease Center. The NIA is part of the National Institutes of Health, Department of Health and Human Services.
The findings are likely to strike a chord among middle-aged and older people interested in preserving cognitive health. "We are asked constantly about this use-it-or-lose-it approach to maintaining memory," says Elisabeth Koss, Ph.D., Assistant Director of the NIA's Alzheimer's Disease Centers Program. "This study provides important new evidence that there may be something to the notion of increased cognitive activity and reduced risk of Alzheimer's disease. Further research should help better sort out whether cognitive activities can be prescribed to reduce risk of AD and why that may be so."
The study followed over 700 dementia-free participants age 65 and older for an average of 4.5 years from their initial assessments. At baseline and then yearly, some 21 cognitive tests were administered to assess various aspects of memory, language, attention, and spatial ability. At the initial evaluations, participants also were asked about time typically spent in seven common activities that significantly involve information processing - viewing television; listening to the radio; reading newspapers or magazines; reading books; playing games such as cards, checkers, crosswords, or other puzzles; and going to museums. The frequency of participating in each activity was rated on a five-point scale, with the highest point assigned to participating in an activity every day or about every day and the lowest point to engaging in an activity once a year or less.
During the follow-up period, 111 people in the study developed AD. In comparing the levels of cognitive activity with diagnosis of AD, the researchers found that the frequency of activity was related to the risk of developing AD. For each one point increase in the participants' scores on the scale of cognitive activities, the risk of developing AD decreased by 33 percent. On average, compared with someone with the lowest activity level, the risk of disease was reduced by 47 percent among those whose frequency of activity was highest.
The researchers also looked at general cognitive decline among the participants. Over the period of the study, the group of older people showed modest age-related declines on several types of memory and information processing tests. There were lower rates of decline, however, in working memory, perceptual speed, and episodic memory among people who did more cognitively stimulating activities.
What accounts for the association between cognitively stimulating activities and reduced risk of cognitive decline and AD is unclear. It may be, some scientists theorize, that cognitive activities are protective in some way. Some speculate that repetition might improve the efficiency of certain cognitive skills and make them less vulnerable to the brain damage in AD. Or, some kind of compensatory mechanisms might be at work, strengthening information processing skills to help compensate for age-related declines in other cognitive areas. The study does not, however, eliminate the possibility that people who develop AD in future years may be less prone, years before, to engage in cognitively stimulating activities. Notes Wilson, "The associations among cognitive activity, Alzheimer's disease, and cognitive function are extremely complex. Additional study, including testing some of these activities as cognitive interventions, will help to tell us whether such enjoyable and easy-to-do activities could be employed in some way to reduce the risk of memory decline and loss." Because the participants in the study have agreed to brain donation, the investigators hope to be able to determine the mechanism underlying the association between cognitive activities and cognitive decline. More than 900 older Catholic clergy from 40 groups across the U.S. are participating in the Religious Orders Study. All participants have agreed to annual memory testing and brain donation at the time of death. "We are grateful for the remarkable dedication and altruism of this unique group of people," says Bennett. "I expect we will learn a great deal more from them, as we look for insights into how the brain functions with age."
The NIA leads the Federal effort to support and conduct research on aging and on AD. The Rush Alzheimer's Disease Center is one of 29 NIA-supported Alzheimer's Disease Centers across the U.S. which conduct basic, clinical, and social and behavioral research on dementia and AD. NIA also sponsors the Alzheimer's Disease Education and Referral (ADEAR) Center, which provides information on AD research to the public, health professionals, and the media. ADEAR can be contacted toll free at 1-800-438-4380 weekdays during business hours or by visiting its website, www.alzheimers.org. Press releases, fact sheets, and other general information materials on aging and aging research can be viewed at the NIA's home website, www.nia.nih.gov.
The National Institute on Aging is a component of the National Institutes of Health, U.S. Department of Health and Human Services