Even modest amounts of daily exercise may slow the progression of Alzheimer’s disease in older people at risk, researchers have said. A 14-year study found that 3,000 steps or more appeared to delay brain changes and cognitive decline.
The study, involving 296 people aged 50 to 90 who were cognitively unimpaired at the start, showed that cognitive decline was delayed by an average of three years in those who walked 3,000 to 5,000 steps a day, and by seven years in those who managed 5,000 to 7,000 steps.
“We’re encouraging older people who are at risk of Alzheimer’s to consider making small changes to their activity levels, to build sustained habits that protect or benefit their brain and cognitive health,” said Dr Wai-Ying Yau, first author of the study at Mass General Brigham hospital in Boston.
The condition is linked to the buildup of amyloid-beta plaques and tau tangles in the brain. Among participants with elevated amyloid at baseline, higher step counts were linked to slower rates of cognitive decline and delayed buildup of tau proteins. In sedentary individuals, the buildup of tau and cognitive decline was substantially faster, the researchers report in the journal Nature Medicine.
While the scientists cannot rule out reverse causation, the data suggests physical activity is protective. Dr Julia Dudley of Alzheimer’s Research UK said: “The findings suggest that even a modest amount of walking each day, around 5,000 steps, is linked to a slower buildup of tau protein in the brain. This gives us a clearer picture of how everyday activity may support brain health.”
Dementia affects an estimated 50 million people worldwide, with Alzheimer’s disease the most common cause. In the UK, more than 500,000 people have Alzheimer’s. Yau said more research is needed, but “it’s very encouraging that physical activity may help to modify someone’s trajectory.”
