Exercise prevents age-related mental decline, recent study results show.

"Even those elderly people who did modest amounts of gentle exercise, such as walking for 15 minutes three times a week, appeared to benefit," said Eric Larson, director of the Group Health Cooperative of Seattle's Center for Health Studies and lead author of the report, published Tuesday in The Annals of Internal Medicine.

Reduce Progression of Pre-existing Problems

Moreover, the research showed that even people who already suffered from some signs of dementia benefited from regular exercise.

"The group that benefited most was the people who were frailest at the start of the study. Based on these findings, we can advise older people to 'use it even after you start lose it' because exercise may slow the progression of age-related problems in thinking," Larson added.

Comprehensive Study

The report is the most definitive yet to link exercise and dementia risk, and was designed to avoid problems that produced mixed results in earlier studies.

The researchers followed 1,750 people aged 65 and older for 6.2 years on average. The patients initially tested normal for mental functions. But during the study, 158 developed dementia and 107 of those subjects were diagnosed with Alzheimer's disease.

Researchers contacted patients periodically to assess how much they were exercising, what they were doing and any changes in physical and cognitive function.

Among the activities that counted as exercise were walking, hiking, aerobics, calisthenics, swimming, water aerobics, weight training and stretching.

Active Group Shows Less Mental Decline

The rate of dementia was 13 for each 1,000 persons in the study over one year among those who exercised three or more times a week, but 19.7 among those who exercised less than that.

Larson believes that exercise may improve brain function by boosting blood flow to areas of the brain used for memory. "Earlier research has shown that poor blood flow can damage these parts of the brain," he said. "So, one theory is that exercise may prevent damage, and might even help repair these areas by increasing blood flow."

'It's Never Too Late'

He argues that it's never too late for older people to begin exercising: "Even if you're 75 and have never exercised before, you can still benefit by starting to exercise now."

But in an accompanying editorial in the journal, Laura Podewils of the federal Centers for Disease Control and Prevention, and Dr. Eliseo Guallar from the Johns Hopkins Bloomberg School of Public Health offered a note of caution. They said that more study is needed to determine whether exercise really does have a cause-and-effect relationship on dementia rates, or if physical activity is simply higher among seniors who are more mentally and socially active or have other beneficial lifestyle or sociodemographic characteristics.

If the link to exercise is confirmed, then more research will be needed to determine the "type, frequency, intensity or duration of physical activity that is most beneficial to preventing cognitive deterioration," they wrote.

(c) Scripps Howard
(c) Daily News Central. All rights reserved.