We know that a sedentary lifestyle isn’t good for your health. Studies on inactivity have led to headlines like “Sitting Can Kill You,” and even spawned the trend of the standing desk. But did you know sitting down too much might affect not just your obesity and diabetes risk, but your brain, too? A new study shows that sitting can be bad for the brain and could inhibit its ability to make new memories.
In a study on middle-aged and older adults, scientists found that the brain structure associated with making memories was thickest in those who moved around a lot throughout the day. Those who sit a lot had thinner medial temporal lobes and surrounding regions.
While loss of thickness in the medial temporal lobe, which regulates long-term and declarative memory, or the recollection of facts, is a natural part of aging, study participants who sat more had less structure in comparison to those in their own age group. Thinning of this area is also one of the first signs of dementia, even before symptoms begin to appear, according to researchers.
The evidence that sitting is associated with thinner brain regions is based on interviews conducted by researchers from University of California, Los Angeles with 35 participants between the ages of 45 and 75. Participants filled out a survey on their sitting habits and then had an MRI, which measured brain thickness.
After adjusting for the participants’ age, the results suggested that each extra hour of sitting per day was associated with a 2 percent decrease in thickness in the medial temporal lobe. Translation: Someone who sits for fifteen hours per day has 10 percent less volume than someone who sits for ten.
Researchers also saw that the brain thinness effect of sitting was present even in those who were very physically active—meaning the effects of sitting on the brain can’t be offset by vigorous exercise.
The study doesn’t shed light on why sitting might cause the brain’s memory center region to shrink, but previous studies on sitting suggest it may have to do with the restriction of blood flow and metabolic processes.
Study authors hope to continue to study the effect sitting has on the brain in larger studies.
This study was published in the journal PLOS One.