The Type of Activity Older Adults Do When Seated Can Impact Dementia Risk, Study Finds

Sitting for long periods of time has been linked with a variety of health issues, from those impacting the heart to those impacting the spine. A new study finds that depending on the type of activity you’re doing while seated, it could also increase dementia risk.

Researchers from the University of Arizona and the University of Southern California investigated the impact of activities people do while seated, specifically those that are more intellectually stimulating and those that aren’t. According to the findings, published in the Proceedings of the National Academy of Sciences, less stimulating activities like watching television may increase your risk of dementia, despite how physically active you are otherwise.


Gene Alexander, study co-author and professor in the University of Arizona Department of Psychology, says, “Although we know that physical activity is good for our brain health, many of us think that if we are just more physically active during the day, we can counter the negative effects of time spent sitting. Our findings suggest that the brain impacts of sitting during our leisure activities are really separate from how physically active we are, and that being more mentally active, like when using computers, may be a key way to help counter the increased risk of dementia related to more passive sedentary behaviors, like watching TV.”

To better understand the impacts of sedentary behaviors on dementia risk, the team analyzed data from the UK Biobank, a medical database with health records for more than half a million residents of the United Kingdom. They looked specifically at 145,000 cognitively healthy adults aged 60 and older who had answered questionnaires on their seated activities between 2006 and 2010. They were followed for an average of about 12 years, with 3,507 of the participants developing dementia.


After adjusting for certain confounding factors that could impact brain health, the team found that time spent watching television was linked with an increased risk of dementia, even in those who reported high levels of physical activity. On the other side, those who spent more time using a computer had a lower risk of dementia.

David Raichlen, lead author and professor of biological sciences and anthropology at the University of Southern California, says, “It isn’t the time spent sitting, per se, but the type of sedentary activity performed during leisure time that impacts dementia risk. We know from past studies that watching TV involves low levels of muscle activity and energy use compared with using a computer or reading. And while research has shown that uninterrupted sitting for long periods is linked with reduced blood flow in the brain, the relatively greater intellectual stimulation that occurs during computer use may counteract the negative effects of sitting.”


So maybe the next time you go down a Wikipedia rabbit hole, you shouldn’t feel too bad for wasting time. You may be helping your brain.

People, Pets & Planet

Help where it’s needed most at GreaterGood for free!