Do You Spend Most of Your Day Seated? It Could Be Harming Your Brain

Have you hit retirement and found yourself lounging around a bit too much? A new study finds you may want to introduce a few active hobbies into your routine, and not just for your body. For your brain, too.

Researchers at the University of Southern California and the University of Arizona recently investigated the link between sedentary behavior and dementia incidence in adults. In a study involving nearly 50,000 people, they found that the more a person sat around, the higher the likelihood that they’d develop dementia. This was true even if people got up intermittently. The findings provide further evidence of the harms of being overly sedentary.

David Raichlen, the study’s first author and professor of biological sciences and anthropology at USC, says, “Many of us are familiar with the common advice to break up long periods of sitting by getting up every 30 minutes or so to stand or walk around. We wanted to see if those types of patterns are associated with dementia risk. We found that once you take into account the total time spent sedentary, the length of individual sedentary periods didn’t really matter.”

The team found that the threshold for increased dementia risk was more than 10 hours a day of sedentary behavior.

The researchers came to these findings, published in JAMA, by looking at data from 49,841 participants 60 or older in a UK Biobank sub-study that involved wearing an accelerometer for a week. None of the participants had dementia at the beginning of the study, but after an average follow-up period of six years, 414 of them had been diagnosed with the disease.

After adjusting for certain factors that could affect brain health, the team found that for those who were only sedentary for up to 10 hours a day, there was no increased risk of dementia. However, at any amount over 10 hours, the risk continued to increase.

Raichlen says, “This should provide some reassurance to those of us with office jobs that involve prolonged periods of sitting, as long we limit our total daily time spent sedentary.”

While the research doesn’t prove that being sedentary caused dementia, there have been other studies demonstrating the benefits of keeping active in older age. One such study found that enjoying active leisure activities was linked with a 17% lower risk of dementia. Interestingly, another USC/University of Arizona study found the activities you do while seated may impact dementia risk. You can read more on that here.