Exercise good for the ageing brain

Two new studies provide more evidence that regular aerobic exercise not only prevents problems with thinking and memory that often come with age, but it can actually help turn back the clock on brain aging.

In one study, researchers found evidence that engaging in moderate physical activity such as brisk walking, swimming, or yoga in midlife or later may cut the risk of developing mild thinking problems. In another study, a group of elderly individuals who already had mild problems had improvements in their mental agility after six months of high-intensity aerobic activity.

People with mild mental impairment (also called mild cognitive impairment), have memory difficulties, such as forgetting people's names or misplacing items. Each year, 10 to 15 percent of individuals with mild cognitive impairment develop dementia, as compared with 1 percent to 2 percent of the general population. Previous studies have suggested that exercise may improve thinking and memory. To investigate further, researchers studied 33 adults with mild cognitive impairment. Twenty-three spent 45 to 60 minutes on a treadmill or stationary bicycle four days a week for six months, while the other 10 participants, who belonged to the “control” group, did stretching exercises but kept their heart rate low.

Six months of intense aerobic exercise improved cognitive abilities of attention and concentration, organisation, planning, and multi-tasking. In contrast, cognitive function test scores continued to decline in the group that didn't exercise.

The researchers are not exactly sure why, for the women in the study, aerobic exercise improved the body's sensitivity to insulin, a hormone that plays an important role in providing energy to the muscles and organs of the body and to the brain. Contrary to expectations, aerobic exercise did not improve insulin sensitivity for the men in the study.

The other study involved 1,324 elderly American adults free of dementia in 2006-2008. Researchers determined that 198 had mild cognitive impairment and 1,126 had normal cognitive function. 

It was found that those who said they had engaged in moderate exercise such as brisk walking, aerobics, yoga, strength training or swimming in their 40s, 50s and beyond were less apt to have mild cognitive impairment. Moderate exercise in midlife was associated with a 40 percent lesser chance of developing mild cognitive impairment, and moderate exercise in late life was associated with a 30 percent reduced risk of mental decline. The findings were consistent among men and women.

These two studies reaffirm the benefits of a physically active lifestyle on the brain.