Sitting for long periods of time is associated with increased risk for diseases such as type 2 diabetes, heart disease and some cancers. It’s even associated with early death. Now research has started to look at the link between sitting with brain function and dementia. But when it comes to brain health, the results aren’t quite clear cut. And sitting may not be as bad for your brain.
Too Much Sitting
We’re not going to get away from sitting, nor should we. At times sitting is needed to take a break from being active, or from being on your feet for long periods. Other times it’s needed to complete complex tasks. And some people find it easier to think and problem solve while sitting. But most of us probably sit a bit too much.
The average person sits about 6 hours per day. But this may be an underestimation. Most studies use surveys to ask people how much time they spend sitting. But these surveys may be unreliable. When compared to directly measuring sitting time (using wearable devices), surveys miss about 1.7 hours of sitting per day. So, it’s more likely the average person sits close to 8 hours per day.
It may also come as no surprise that the amount of sitting has increased in recent years. In 2016 adults in the US sat for one hour more per day than they did in 2001. This is similar to what’s reported in other countries. And as more and more activities become automated, it’s likely the amount of time people are sitting will continue to increase.
Sitting is Bad for Your Brain
Studies have begun to report a link between sedentary time (which is mostly sitting) and dementia. One study found that for seniors, sitting more than 9.7 hours per day increased the chances of getting dementia by up to 50%. And for every hour of watching TV, the chances increased by 24%. And while physical activity is associated with lower chances for dementia, being active doesn’t seem to offset the effects of sedentary time. Suggesting that it’s just as important to reduce sedentary time as it is being active.
High amounts of sitting have also been linked to changes in the brain. Brain volume and white matter may be smaller in people who sit more compared to those who don’t. Both of which are associated with cognitive decline. And sedentary time was related to changes in the brain that were associated with decreased brain function such as slower processing speed related to memory.
We might think of high amounts of sitting and sedentary behaviour to be only a concern of high-income countries. But that’s not the case. Sedentary behaviour in people living in low and middle-income countries was associated with greater chances to develop mild cognitive impairment, which often occurs before dementia.
One can’t really say sitting is responsible for people getting dementia as these are only observational studies. It’s possible people with early or undiagnosed dementia may be inclined to sit more. However, a study in kids under five years found that the more screen time a child had (which is usually sedentary time too), the slower their development, suggesting the effects of sedentary behaviour on the brain begin at an early age.
But is it?
Most studies linking sedentary behaviour and sitting time to dementia look at total sedentary time or sitting watching TV. But not all sedentary time is watching TV. Some activities may be more mentally stimulating. And what you do while sitting may be more important than the sitting itself.
When studies look at different activities while sitting, those that require more thought seem to be better than passive activities. For example, time spent using a computer was associated with less chance of dementia, while watching TV was associated with a greater chance. Reading, writing, solving puzzles, playing board games and using a computer were all associated with less dementia. But not all studies agree that passive activities, such as reading, may be beneficial.
This coincides with other research indicating that active mental activities (games, puzzles, journaling, computer work, taking classes) may be related to lower rates of dementia. While passive activities such as reading and watching TV weren’t.
How This Can Help You
While sitting is associated with greater chances of many physical diseases, when it comes to your brain, also consider what you are doing when sitting. Regardless, it’s best to get up and move around every 20-30 minutes. This movement is good for your body but can also be good for your creativity, energy and productivity.
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