June 11, 2025
In older men and women, spending a lot of time sitting is associated with worse cognition and brain changes that may predispose to Alzheimer’s disease, according to a new report. The detrimental effects of prolonged sitting persisted even in those who got regular exercise.
“Reducing your risk for Alzheimer’s disease is not just about working out once a day,” said study leader Marissa Gogniat, an assistant professor of Neurology at the University of Pittsburgh and a former postdoctoral fellow at the Vanderbilt Memory and Alzheimer’s Center. “Minimizing the time spent sitting, even if you do exercise daily, reduces the likelihood of developing Alzheimer’s disease.”
For the study, Dr. Gogniat and her colleagues looked at 404 older men and women from the Vanderbilt Memory and Aging Project, a long-running study of aging and brain health. Their mean age was 71. Most were cognitively normal when the study began, though about 20 percent had early signs of mild cognitive impairment, a form of memory loss that can eventually lead to full-blown dementia.
Researchers assessed participants’ general physical activity levels by having them wear activity monitors on their wrists over a typical week. While on average they spent about 13 hours a day being sedentary, it was a fairly physically active group: Most met standard exercise recommendations to get at least 150 minutes of moderate exercise or 75 minutes of vigorous exercise per week.
Over the next seven years, participants also underwent tests of memory and thinking skills as well as periodic MRI brain scans to assess physical brain changes.
The researchers found that those who spent the most time being sedentary scored worse on memory tests than their more active peers. Those who spent the most time sitting also had greater shrinkage in the hippocampus and other brain regions affected by Alzheimer’s disease; loss of volume in these areas is a sign of increased dementia risk. Sedentary behavior remained an independent risk factor for Alzheimer’s disease, regardless of how much exercise someone got.
Brain impairments were particularly pronounced in sedentary individuals who carried the APOE-E4 gene variant, which increases the risk of Alzheimer’s disease. The findings suggest that those who inherit the gene variant should be especially vigilant about taking breaks from sitting throughout the day and move around to increase their time being physically active.
“This research highlights the importance of reducing sitting time, particularly among aging adults at increased genetic risk for Alzheimer’s disease,” said study author Angela Jefferson, a professor of Neurology and director of the Vanderbilt Memory and Alzheimer’s Center. “It is critical to our brain health to take breaks from sitting throughout the day and move around to increase our active time.” The study was published in the journal Alzheimer’s & Dementia.
The findings underscore just how bad sedentary behaviors can be for the body overall. Past research showed that people who sat much of the day were more likely to develop heart disease, obesity, diabetes and other illnesses that are tied to an increased risk of Alzheimer’s disease. A growing body of evidence suggests that prolonged sitting can also take a serious toll on the brain itself.
If you do find yourself sitting a lot, take regular breaks to take a walk and get some exercise. In addition, some research suggests that not all sitting is the same when it comes to brain health. Older men and women who sat for long periods doing passive activities like watching TV, for example, were at higher risk of developing dementia than those who engaged in cognitively stimulating activities like reading, doing crafts or completing crossword puzzles. Find mentally stimulating tasks that you enjoy for those down times. Your brain may thank you in the long run.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Marissa A. Gogniat, Omair A. Khan, Chorong Park, et al: “Increased sedentary behavior is associated with neurodegeneration and worse cognition in older adults over a 7-year period despite high levels of physical activity.” Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association, May 13, 2025
