How to fight brain ageing (by Mind your body of the Straits Times dated 21 Jan 2010)

Physical exercise can prevent mild thinking problems and improve the mental agility of those with some impairments, researchers find

Regular exercise may not just improve thinking and memory in the elderly. It may help turn back the clock on brain ageing.

Two new studies provide more evidence that regular aerobic exercise can be effective in this regard.

In one study, researchers found evidence that engaging in moderate physical activity such as brisk walking, swimming or yoga in mid-life or later may cut the risk of developing mild thinking problems.

In the other 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 impairments - known as mild cognitive impairment - typically have some memory difficulties such as forgetting people's names or misplacing items. Each year, 10 to 15 per cent of people with mild cognitive impairment will develop dementia, as compared with 1 to 2 per cent of the general population.

Seattle-based 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 control subjects did stretching exercises but kept their heart rate low.

Six months of intense aerobic exercise improved the subjects' cognitive abilities, including attention and concentration, organisation, planning and multi-tasking, lead researcher Laura Baker noted in an e-mail message to Reuters Health. In contrast, the cognitive function test scores continued to decline in the group that did not have vigorous exercise.

In the other study by Dr Yonas Geda and colleagues at Mayo Clinic in Rochester, Minnesota, 1,324 elderly adults free of dementia were monitored from 2006 to 2008. Experts determined that 198 had mild cognitive impairment and 1,126 had normal cognitive function.

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, the researchers found.

Both studies, published in the Archives Of Neurology, contribute to a growing body of literature supporting the benefits of a physically active lifestyle on the brain.