BALTIMORE (April 26,2005) - Older people who stay active in a wide variety of ways seem to have a better chance of warding off dementia, according to research that found it's the diversity, not intensity, of the exercise that counts.
And the pastimes can range from gardening to aerobics.
"It's not necessarily the energy you spend," said Dr. Constantine Lyketsos, a Johns Hopkins University epidemiologist and the study's lead author. "It's the variety that matters."
The findings come as no surprise to 73-year-old Blanche Shoul, who walks daily at the Towson Town Center, where she also works as a customer service representative.
"I've been doing it all my life," she said. "Mentally, I think I'm just as sharp as when I worked for the state for 31 years."
Shoul said she also bicycles and exercises with weights twice a week, as well as doing aerobics and playing board games.
Researchers tracked 3,375 men and women over age 65 from 1992 to 2000, surveying them on the kinds of activities they did. Those doing the widest variety were far less likely to develop dementia, the researchers found.
The volunteers were questioned about the frequency and duration of the 15 most common physical activities in older adults - walking, household chores, mowing, raking, gardening, hiking, jogging, biking, exercise cycling, dancing, aerobics, bowling, golfing, general exercise and swimming.
The findings also suggest that even sedentary activities such as card-playing may be beneficial, Lyketsos said.
"Exercising your body is exercising your brain, by the way, because the brain is central to the coordination of any exercise movement," he said.
The reason for the link between the number of activities and the lower rate of dementia is not clear, Lyketsos said, but it may be that a variety of activities keeps more parts of the brain active. Or it could be that the variety may show the person is more socially and physically active overall.
The study was published this month in the American Journal of Epidemiology.
Dementia encompasses a group of diseases, including Alzheimer's disease, that gradually destroy brain cells and lower mental function, according to the Alzheimer's Association. An estimated 4.5 million Americans have Alzheimer's disease, a number that has doubled since 1980 and is expected to reach as much as 16 million by 2050.
The Johns Hopkins researchers said the exercise link applied to all types of dementia, except for those with a certain genetic predisposition to the disease found in one-quarter to one-third of Alzheimer's patients.
Of the nearly 3,400 people tracked in the study, 480 developed some form of dementia. Those who took part in just one activity or none at all accounted for 130 of the cases. Those who did four or more activities accounted for 84 of the dementia cases. Researchers adjusted the results for various factors and determined that the greater the number of physical activities, the lower the risk of dementia seemed to be.
Dr. Barry Reisberg, clinical director of New York University's Silberstein Aging and Dementia Research Center, said previous research has shown exercise produces neurons in the brains of rodents.
"So, certainly, exercise is a helpful activity," said Reisberg, who was not involved in the Hopkins study.
The least active participants in the study, however, may have been less active as a result of the early stages of dementia, he said, adding that more research is needed.
CHICAGO (Reuters) Sep 21, 2004 - Elderly people who take regular walks are less likely to suffer dementia than those who take little exercise, a pair of studies said on Tuesday.
Keeping active has already been proven to lessen the risk of heart disease, cancer and diabetes. Now moderate daily exercise such as long strolls has been found to keep elderly minds healthier, said the authors of studies published in this week's issue of the Journal of the American Medical Association.
"We now have evidence that regular walking is also associated with benefits that are related to cognitive function later in life," said Robert Abbott, a biostatistician at the University of Virginia Health System.
His study tracked the habits and mental functioning of 2,257 Hawaiian Asian-American men aged 71 to 93 years and found those who walked less than one-quarter mile a day were 1.8 times as likely to develop dementia than men who walked at least two miles a day.
The second study, involving elderly women participating in the Nurses' Health Study at Boston's Brigham and Women's Hospital, found those who exercised regularly -- such as walking at an easy pace for 1-1/2 hours a week -- were less likely to suffer mental decline.
"What is most striking is that for older women who are able to engage in several hours per week of physical activity (for example, walking at least six hours per week), their cognitive function seemed to be comparable to that of a woman several years younger," said study author Jennifer Weuve of the Harvard School of Public Health.
More active people also tended to have a healthier lifestyle and eat a better diet than sedentary people, which could also help preserve mental acuity, Abbott said.
"There is also the possibility that people who walk are less likely to get diseases later on in life that could lead to dementia versus people who are inactive," he said.
