A new study has found that regular physical activity during midlife and later years can cut the risk of developing dementia by up to 45%. Researchers tracked over 4,000 adults across three life stages – early adulthood, midlife (ages 45–64), and late life (ages 65–88) – for several decades. They discovered that those who were most active in their 50s, 60s, and 70s had a 41-45% lower risk of all-cause dementia, including Alzheimer’s disease, compared to the least active individuals.

The protective effect of exercise was especially strong in midlife and late life, while activity in early adulthood did not show a measurable impact on dementia risk later on. Importantly, these benefits were seen even in people with a genetic predisposition to dementia, highlighting that lifestyle choices can make a significant difference.

The researchers explain that physical activity supports brain health by improving brain structure and function, reducing harmful proteins linked to Alzheimer’s, lowering inflammation, and boosting cardiovascular health. The findings reinforce the message that it is never too late to start moving – maintaining an active lifestyle from middle age onward is a powerful way to help preserve cognitive health and independence as we age.

Links
Marino, F.R., Lyu, C., Li, Y., Liu, T., Au, R. & Hwang, P.H. (2025) ‘Physical activity over the adult life course and risk of dementia in the Framingham Heart Study’, JAMA Network Open, 8(11), p. e2544439. doi: 10.1001/jamanetworkopen.2025.44439.