A new study has revealed that sitting for long periods each day can lead to brain shrinkage, even among individuals who meet recommended exercise guidelines, Earth.com reports.
The findings challenge the widely held belief that regular physical activity alone is sufficient to protect long-term brain health.
Researchers from Vanderbilt University’s Memory and Alzheimer’s Center followed older adults over a seven-year period, tracking their activity levels and changes in brain volume using wrist-worn movement monitors and MRI scans. On average, participants sat for about 13 hours a day.
The study found that prolonged sitting was associated with reduced brain volume, particularly in areas responsible for memory and decision-making, such as the hippocampus, frontal lobe, and parietal lobe. Importantly, the detrimental effects of sitting were observed even among those who exercised regularly for at least 150 minutes per week.
Lead researchers pointed out that although exercise supports brain health, it does not fully offset the impact of excessive sedentary behavior. The findings suggest that regular movement throughout the day may be necessary to preserve brain volume and cognitive function as people age.
The study also examined participants with a genetic predisposition to Alzheimer’s disease. Carriers of the APOE-ε4 gene, known to increase Alzheimer’s risk, showed more pronounced brain shrinkage when sedentary. These individuals experienced more difficulty with memory-related tasks, such as word recall and object naming.
One potential explanation is that extended sitting reduces blood flow to the brain, lowering oxygen and nutrient delivery. This decrease in circulation, combined with increased inflammation, may weaken neural connections and accelerate age-related decline.
To mitigate these risks, researchers recommend incorporating frequent movement throughout the day — standing during phone calls, taking short walks, or stretching between tasks — rather than relying solely on structured workouts.
