# Is Lack of Physical Activity Tied to Dementia Risk?
The connection between physical activity and brain health has become increasingly clear through recent scientific research. A major study published in JAMA Network Open found that people who maintain high levels of physical activity during middle age and later years have significantly lower risks of developing dementia compared to those who are sedentary.
The research tracked thousands of participants from the Framingham Heart Study over several decades, monitoring their activity levels at different life stages. The findings were striking: individuals who were most physically active in midlife had a 41 percent lower risk of developing dementia, while those who stayed active in late life saw their risk drop by 45 percent. This suggests that staying active becomes increasingly important as you age.
What makes this research particularly valuable is that it identified when physical activity matters most. Interestingly, the study found that physical activity levels in early adulthood did not show a significant connection to later dementia risk. This means that even if you were not very active in your twenties and thirties, you can still benefit greatly by becoming more active in your forties, fifties, and beyond.
The protective effects of exercise appear to work through several biological mechanisms. Exercise can reduce chronic inflammation, which has been linked to increased dementia risk. Additionally, staying active may help interrupt the buildup of harmful plaques and proteins in the brain before they cause serious damage. For people carrying genetic risk factors like the APOE e4 gene, which increases Alzheimer’s disease risk, high physical activity was still associated with a 66 percent lower risk of dementia.
You do not need to become an athlete to see benefits. Research shows that even modest amounts of physical activity provide protection. A 2022 study found that people who walked just 3,800 steps per day lowered their dementia risk by 25 percent, with greater benefits coming from more activity. Another study examining older adults found that benefits increased up to a moderate activity level of 5,001 to 7,500 steps per day, after which the protective effects plateaued.
Even short bouts of exercise help. Studies show that 20 to 30 minutes of daily activity provides some protective effect, though more exercise generally offers more protection. Using a bicycle instead of a car, bus, or train for transportation has been linked with a 19 percent lower risk of dementia and a 22 percent reduced risk of Alzheimer’s disease specifically.
For those starting or restarting an exercise routine at midlife or later, experts recommend beginning slowly and gradually building up your routine rather than trying to immediately match what you could do years ago. Building consistent daily habits, such as walking for 20 minutes before work or taking a short movement break during lunch, can help ensure you stay active regularly.
The evidence strongly suggests that physical inactivity is a modifiable risk factor for dementia. Unlike genetic factors you cannot change, your activity level is something you can control. The research indicates that interventions targeting physical inactivity could be a promising strategy for slowing cognitive decline and potentially preventing or delaying dementia, particularly when started or maintained during middle age and beyond.
Sources
https://dallasexaminer.com/exercise-brain-health-study/
https://pmc.ncbi.nlm.nih.gov/articles/PMC12728325/
https://www.uclahealth.org/news/article/how-exercise-can-reduce-dementia-risk
https://www.rushu.rush.edu/news/can-healthy-lifestyle-reduce-dementia-risk
https://www.consultant360.com/exclusives/could-exercise-prevent-dementia
