DO LEISURE ACTIVITIES OFFER PROTECTION FROM ALZHEIMER'S DISEASE?

SAN DIEGO—Participating in recreational activities in midlife appears to offer protection from neurodegeneration, according to Robert P. Friedland, MD, and colleagues. "People who were less active were more than three times more likely to have Alzheimer's disease as compared to those who were more active," said Dr. Friedland, Associate Professor of Neurology, Psychiatry, and Radiology. He and colleagues at Case Western Reserve University School of Medicine and University Hospitals of Cleveland studied the association between physical and mental activities in adulthood and the development of Alzheimer's disease. Dr. Friedland presented the results of the study at the 52nd Annual Meeting of the American Academy of Neurology.

ACTIVITIES THE MEASURE

During the study, information about participation in leisure activities was collected from a population of patients with Alzheimer's disease (n = 193) and from controls (n = 358). Questions about participation in 26 passive, intellectual, and physical activities (see table) were included on the questionnaire. The study participants were asked which activities they had participated in and for how long each month they had participated in these activities during their 20s, 30s, 40s, and 50s. Data on participation after age 60 or during the five-year period prior to disease onset (whichever was first) was not sought because of the possible confounding effects of premorbid or morbid illness on participation in the activities.

INTELLECTUAL ACTIVITY LINKED WITH REDUCED RISK

Controls reported participating in a greater diversity of activities at a greater frequency than cases. Individuals who had participated more often in intellectual activities in their 20s and 30s were at a lower risk for Alzheimer's disease. However, individuals who had increased their intellectual activities after their 30s also reduced their risk of Alzheimer's disease, according to the researchers. "A relative increase in the amount of time devoted to intellectual activities from early adulthood (age, 20 to 39) to mid adulthood (age, 40 to 60) was associated with a significant decrease in the probability of having Alzheimer's disease later in life," said Dr. Friedland.

"Our body parts age in regard to how often they are used," Dr. Friedland explained. "People who learn new tasks are exercising nerve cells and these nerve cells are actually changing in structure and chemistry with activity. Nerve protein synthesis is occurring, nerve filaments are growing, and neural growth factors are secreted, and conductivity and chemical complexity [are] changed by how nerve cells in the brain are being used."

PROTECTIVE BENEFITS OF EXERCISE LESS CLEAR

Physical exercise was also greater in the control group than in the case group. However, it is not clear whether physical activity offers a protective benefit from the neurodegeneration or whether decreased participation in physical activity is a sign of premorbid Alzheimer's disease. The researchers advised that people who participate in physical activities may help reduce their risk of Alzheimer's disease by lowering their body weight, improving their diet (consuming more antioxidants and reducing fat intake), improving blood pressure and cardiovascular health, and reducing the risk of blood clotting.

IMPLICATIONS FOR PUBLIC POLICY?

Although youth contributes to the establishment and maintenance of synapses, neuronal activation may offer beneficial effects on membranes and amyloid beta protein production, degradation, and aggregation, explained the researchers. Humans are genetically equipped to be active throughout their entire life, they noted. The researchers also pointed out that developing countries, which have higher rates of activity, also have lower rates of Alzheimer's disease—despite high apolipoprotein epsilon4 allele frequency. "It's important to be active," Dr. Friedland said. "We are not genetically designed by evolution to be couch potatoes."

Although the relationship between recreational activities and the subsequent development of neurodegenerative disorders has not been fully studied, Dr. Friedland and his colleagues believe their findings have significant implications for public policy. "We believe that health measures should be instituted to enhance adult participation in physical and mental activities, and decrease participation in activities that involve little physical or intellectual stimulation, such as television," Dr. Friedland concluded.

—Kathryn Blair
Associate Editor

Activity Categories and Activity Types

Passive Watching television Listening to music Attending social clubs Talking on the telephone, visiting with others Attending church or synagogue activities Intellectual Reading Working on jigsaw puzzles Working on crossword puzzles Playing a musical instrument Craftwork Painting, drawing, other art Woodworking Letter writing Playing cards Playing board games Home repairs, doing handywork Knitting, crocheting, other needlework Physical Baseball, football, basketball, soccer, hockey Working out in a gym Racquet sports Bicycle riding Golfing, bowling Gardening Ice skating, roller skating Jogging, swimming Walking for exercise

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