Regular Exercise May Ward Off Cognitive Decline

If you’ve been looking for a reason to begin an exercise program or get back into working out regularly, the results of two new studies may give you the inspiration you need. Researchers found that people who participated in moderate physical activity in midlife or later had a reduced risk of mild cognitive impairment (MCI) and a six-month high-intensity aerobic exercise program improved the cognitive function of individuals who already had the condition.

Less severe than dementia, MCI is defined as cognitive defects that are evident but do not interfere with daily living, such as slower thinking, reduced ability to learn, and impaired memory. Each year, about 10 to 15 percent of people with MCI progress to dementia, compared with 1 to 2 percent of the general population. As the average life span continues to lengthen, it becomes even more important to find ways to minimize age-related mental decline. Previous research has suggested that exercise may improve cognitive function.

In one of the recent studies, Dr. Yonas E. Geda and colleagues at Mayo Clinic in Rochester, Minnesota analyzed data on 1,324 individuals without dementia who completed a questionnaire about physical activity between 2006 and 2008 as part of the Mayo Clinic Study of Aging. The participants had an average age of 80 and were classified as having normal cognition (1,126) or MCI (198).

Those who reported performing moderate exercise such as yoga, aerobics, strength training, swimming or brisk walking during midlife were 39 percent less likely to develop MCI, while moderate exercise later in life was associated with a 32 percent reduction. The findings were consistent among men and women. However, light exercise, such as bowling, golfing with a cart or slow dancing, or vigorous exercise, including jogging, racquetball and skiing, were not associated with reduced risk for MCI. “Our findings contribute to the growing body of literature that indicates the potentially beneficial relationship between physical exercise and cognition,” the authors conclude.

The Mayo team says exercise may protect against MCI through production of nerve-protecting compounds, increased blood flow to the brain, improved development and survival of neurons, and decreased risk of heart and blood vessel diseases, but that it may be that physical exercise is simply a marker for a healthy lifestyle. “A subject who engages in regular physical exercise may also show the same type of discipline in dietary habits, accident prevention, adherence to preventive intervention, compliance with medical care and similar health-promoting behaviors.” The researchers conclude that future study is needed to confirm the association between exercise and the decreased risk of MCI and provide additional information on cause and effect relationships.