Maintaining regular physical activity from middle age onwards could dramatically reduce your risk of developing dementia, according to groundbreaking new research from the long-running Framingham Heart Study.
The Framingham Study's Groundbreaking Findings
The research, published on 19th November 2025, analysed data from 4,290 participants tracked over several decades through the Framingham Heart Study Offspring cohort. This extensive study began in 1971, monitoring the adult children of the original Framingham participants and their spouses with regular health assessments every four to eight years.
Participants self-reported their physical activity levels, including both incidental movement like stair climbing and vigorous exercise, starting from 1971 through subsequent decades. Researchers categorised them into three age groups for analysis: young adulthood (26-44), midlife (45-64), and older adulthood (65 and over).
Striking Results Across Age Groups
During the follow-up period, 13.2% of participants (567 people) developed dementia, predominantly in the older age group. When researchers examined exercise patterns, the results were remarkable.
Those with the highest activity levels during midlife and later life were 41-45% less likely to develop dementia compared to their sedentary counterparts. This protective effect remained significant even after accounting for demographic factors like age and education, plus chronic health conditions including high blood pressure and diabetes.
Interestingly, physical activity during early adulthood showed no significant impact on dementia risk, suggesting the critical window for protective benefits begins around age 45.
Genetic Risk and Exercise: A New Discovery
The study broke new ground by examining how exercise interacts with the APOE ε4 allele, a known genetic risk factor for Alzheimer's disease. The analysis revealed crucial timing differences in how physical activity benefits different genetic profiles.
In midlife, higher physical activity only reduced dementia risk in people without this genetic predisposition. However, in later life, staying active provided meaningful protection for both genetic carriers and non-carriers alike.
This offers hope for those with family history of dementia that beginning or maintaining exercise routines later in life can still significantly impact their cognitive health.
Study Limitations and Public Health Implications
While the findings are compelling, researchers acknowledge limitations including self-reported activity data and a cohort predominantly of European ancestry from the same Massachusetts town, which may limit generalisability to more diverse populations.
Nevertheless, the message for public health is refreshingly straightforward: moving more at any age benefits brain health, with particularly strong protective effects emerging from midlife onwards. For healthcare professionals and individuals concerned about cognitive decline, this adds substantial weight to exercise recommendations across the lifespan.
