There have been many studies linking exercise with benefits for the brain but no-one’s been too sure about whether that’s the exercise itself or from a general increase in heart health. Before I go on, there’s no doubt that if you have low levels of heart risk factors such as not smoking, no diabetes and low blood pressure and cholesterol, then your risk of dementia is also lower. But what about exercise in its own right?
This study in Boston followed older people for six years performing regular brain scans including one which detected amyloid which builds up in the brains of people destined to develop Alzheimer’s disease. They also measured brain volume – which tends to decline as we age – as well as the hippocampus which is involved in laying down memories.
People who exercise lost less brain volume, showed fewer effects on the hippocampus and were less likely to have cognitive decline. Surprisingly, the people who had the most amyloid in their brains and in theory therefore were more at risk of Alzheimer’s had the greatest benefit from exercise.
The influence of exercise was independent of the heart health of the individuals, suggesting exercise had a direct effect on brain tissue. The effects of exercise were greater the more exercise a person took but the average in the study was 8000 steps a day.
As has been said before, if exercise were a drug, they’d charge a fortune for it and every doctor would be prescribing it like mad.