Spending too much time sitting and being inactive could increase the risk of dementia in older adults, warns a recent study conducted by researchers from USC and the University of Arizona. The study, published in JAMA, found that adults aged 60 and above who engage in sedentary behaviors, such as sitting for extended periods while watching TV or driving, face a higher risk of developing dementia.
What's especially concerning is that the risk of dementia significantly rises for those who spend over 10 hours a day being sedentary. This finding is noteworthy because the average American is sedentary for about 9.5 hours each day.
The study also revealed that it's not just about how sedentary time accumulates during the day; the total amount of sedentary time matters most. Whether you sit for long stretches or take short breaks throughout the day, the risk of dementia is similar. So, simply breaking up long periods of sitting with short walks may not be enough to mitigate this risk.
This study highlights the importance of reducing sedentary time for better brain health as we age. So, it's a good idea for adults, especially those in their senior years, to find ways to stay active and avoid excessive sitting to protect against the risk of dementia.
The researchers analysed data from the UK Biobank, which involved over 100,000 adults wearing movement-measuring devices for a week. They focused on approximately 50,000 adults over 60 without dementia at the study's outset.
After around six years of follow-up, the researchers discovered a clear link between high levels of sedentary behavior and dementia risk. Surprisingly, they also found that there's a threshold—spending more than 10 hours sedentary each day—that significantly elevates the risk.
The good news is that lower levels of sedentary behavior, up to around 10 hours, were not associated with increased dementia risk. This suggests that if you have a job that requires a lot of sitting, you can still reduce your risk by limiting your total daily sedentary time.
“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,” said study author David Raichlen, professor of biological sciences and anthropology at the USC Dornsife College of Letters, Arts and Sciences.