For many of us, one of our greatest fears of approaching old age is the risk of dementia. Now it seems that regular exercise may be beneficial to ongoing cognitive, as well as cardiovascular, health. Researchers at the Ageing Research Centre of Sweden's Karolinska Institute report in The Lancet Neurology that taking regular exercise during midlife can dramatically decrease a person's chance of developing Alzheimer's disease, the most common form of dementia.

The study involved almost 1,500 people, aged between 65 and 79, whose levels of physical activity had been surveyed at intervals during the 1970s and 1980s. Those who had exercised for at least 20 minutes twice a week during their late forties and early fifties had cut their risk of developing dementia by about 50%, with exercise apparently most beneficial to those at a higher genetic risk of developing Alzheimer's disease.

Dr Miia Kivipelto, who led the research, said, “These findings may have wide implications for preventative healthcare ... If an individual adopts an active lifestyle in youth and at mid-life, this may increase their probablility of enjoying both physically and cognitively vital years later in life” (The Scotsman, 5 October 2005).

The results did not change when health risks such as smoking and drinking were taken into account, which suggests that exercise itself makes a difference, and that the findings are not influenced by the probability that those who live healthier lifestyles are more likely to exercise.

According to an Alzheimer's Society spokeswoman, “This study backs up the evidence so far ... Studies seem to suggest that leading a healthy lifestyle — exercising regularly and eating a balanced diet — helps protect against dementia” (BBC News Online, 4 October 2005).