Gaby
We spend a big part of the day sitting—at work, on the couch, or commuting. A recent study of older adults found that prolonged sitting can shrink brain volume and harm cognition. Surprisingly, those effects weren’t offset by how much exercise people did.
A team of neurologists from Vanderbilt University, the University of Pittsburgh, and Seoul National University challenged the idea that periods of sitting can be canceled out by periods of activity—at least for people 50 and older.
What Did the Researchers Find?
The researchers say excessive sitting or lying down—in other words, a sedentary lifestyle—can raise the risk of developing several types of dementia later in life, including Alzheimer’s disease.
More than 400 volunteers took part in the study. Researchers tracked their activity with fitness trackers for a week, then followed their cognition with tests and brain scans over the next seven years, as reported by ScienceAlert.
Even though 87 percent of the participants met recommended weekly exercise guidelines (at least 150 minutes of moderate-intensity activity), people who spent more time sitting showed declines in cognitive function.
They also showed more signs of neurodegeneration, including faster thinning of the hippocampus—the brain region key to memory and one of the first areas affected in Alzheimer’s disease.
The team believes a sedentary lifestyle speeds brain aging and says the best response is to reduce sitting time rather than simply trying to increase exercise duration.
The analysis found a stronger link between prolonged sitting and reduced brain volume in people with a higher genetic risk for Alzheimer’s disease.
“This study highlights the importance of reducing sitting time, especially among older adults with an increased genetic risk for Alzheimer’s,” said co-author Angela Jefferson. “Overall, studying lifestyle and its impact on brain health as we age is incredibly important.”
These findings shouldn’t discourage vigorous physical activity. Exercise still offers major benefits for both physical and mental health.
The study was published in the journal Alzheimer’s & Dementia.
