While too much sedentary time sitting around can be bad for brain health, but a new study adds that what you do while you sit matters.
Ever since Tim Cook uttered the phrase “sitting is the new cancer” in an early advertisement for the Apple Watch in 2015, the phrase and its brother “sitting is the new smoking” have been debated by everyone from health professionals to armchair wellness enthusiasts.
Though it’s now widely believed that being perpetually sedentary can be bad for your health, new research is getting into the specifics of why it’s bad, how it’s bad — and how we can make the most of the time we spend sitting. Researchers at the University of Arizona and the University of Southern California, published a new study in the journal Proceedings of the National Academy of Sciences, detailing how different types of passive behavior relate to a dementia diagnosis.
Study author David Raichlen and his team studied the effects of different types of behaviors when people over age 60 are sedentary for long periods of time and found that passive behaviors like watching TV may create a higher risk for developing dementia. On the flip side, they saw that staying mentally active and engaged while sedentary is more important than the amount of time that a person spends sitting down.
“It isn’t the time spent sitting, per se, but the type of sedentary activity performed during leisure time that impacts dementia risk,” Raichlen, a professor of biological sciences and anthropology at USC, explained.
Study author Gene Alexander added that even the individuals who said they got plenty of physical exercise were still at greater risk of developing dementia if they spent a lot of time sitting down watching television.
“Although we know that physical activity is good for 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,” Alexander said.“Our findings suggest that the brain impacts of sitting during our leisure activities are really separate from how physically active we are.”
The trick, Alexander said, isn’t just trying to balance sedentary time with physical activity — rather, there seem to be strong benefits from staying mentally active, even when you’re just sitting around. “Being more mentally active may be a key way to help counter the increased risk of dementia related to more passive sedentary behaviors, like watching TV,” he said.
Keep the brain energized while sitting
Everyone spends part of their day sitting. The good news from this study is using that time intentionally and spending more sedentary time on activities that engage the brain can help protect brain health.
“While research has shown that uninterrupted sitting for long periods is linked with reduced blood flow in the brain,” Raichlen noted, “the relatively greater intellectual stimulation that occurs during [for example, some types of] computer use may counteract the negative effects of sitting.”
According to the researchers, the reason for the difference between types of sedentary activities comes down to muscle activity and energy. While watching TV doesn’t require energy and has little to no muscle activity, reading or surfing the web requires the brain to expend some energy. Raichlen says this could have something to do with blood flow.
The study’s researchers got their data from the U.K. Biobank, a biomedical database with more than 500,000 self-reporting participants across the United Kingdom; 145,000 of those users engaged in a questionnaire from 2006 to 2010 about their sedentary behavior. At the beginning of the data collection in the early 2000s, none of the study participants had a dementia diagnosis, and after a decade of follow-up from researchers, 3,507 had developed dementia, according to the research.
Don’t forget good old physical activity
As new research about the relationship between movement and brain health emerges, it can be hard to keep track of all the different guidelines. If you’re looking to keep it simple, a study conducted at Massachusetts General Hospital found that participants who walked 8,900 steps per day had the overall best brain health results.
Research also shows it’s never too early to start paying attention to how much time you spend being active. Becoming consistent about being active in middle age pays off once you reach your older years. Even small doses of physical activity help. A Boston University School of Medicine study indicated that even light physical activity contributes to keeping the brain healthy. Additionally, neuroscientists at Oregon Health and Science University found that every individual instance of activity and exercise contributes to activating the brain.
