Brain scans of 638 people past the age of retirement showed those who were most physically active had less brain shrinkage over a three-year period. Exercise did not have to be strenuous – going for a walk several times a week sufficed, the journal Neurology says.
But giving the mind a workout by doing a tricky crossword had little impact. The study found no real brain-size benefit from mentally challenging activities, such as reading a book, or other pastimes such as socialising with friends and family.
When the researchers examined the brain’s white matter – the wiring that transmits messages round the brain – they found that the people over the age of 70 who were more physically active had fewer damaged areas than those who did little exercise. And they had more grey matter – the parts of the brain where the messages originate.
Experts already know that our brains tend to shrink as we age and that this shrinkage is linked to poorer memory and thinking. And previous studies have shown that exercise helps reduce the risk of dementia and can slow down its onset.