Spending hours sitting every day? New research shows it could shrink your brain even if you exercise regularly

A study reveals that sitting for extended periods contributes to brain shrinkage and cognitive decline in older adults, regardless of physical activity.

Even if you're staying active, spending too much time sitting, whether at your desk or on the couch, could be quietly affecting your brain. New research suggests it might actually lead to shrinkage in areas linked to memory and cognition.

Prolonged sitting linked to memory decline and brain shrinkage in older adults. (Freepik)

Research suggests that sitting for long periods may harm your brain, even if you exercise regularly. In a seven-year study, older adults who sat more showed greater brain shrinkage and mental decline, even when meeting CDC activity guidelines. The findings challenge the idea that regular workouts can undo the damage of too much sitting.

Impact of sitting on brain health

Researchers at Vanderbilt University's Memory and Alzheimer's Center tracked 404 older adults (average age 71) over seven years using wrist monitors to measure activity levels. Participants averaged 13 hours of sitting daily, a number that adds up quickly with commuting, desk jobs, meals, and downtime.

Study found that prolonged sitting is linked to brain shrinkage and memory decline. (Pixabay)

Those who sat more had thinning in brain regions tied to memory and Alzheimer's, along with poorer performance on memory tests. They also experienced faster loss of hippocampal volume, a key brain area for memory that's among the first to decline in Alzheimer's.

What the study revealed

The study revealed a worrying connection between sitting and brain health, especially for those carrying the APOE-ε4 gene variant, which increases Alzheimer's risk. APOE-ε4 carriers who spent more time sitting saw significantly greater reductions in brain matter, particularly in the frontal and parietal lobes, compared to non-carriers with similar sitting habits. Published in Alzheimer's & Dementia, the research found that these individuals are at higher risk for neurodegeneration linked to sedentary behaviour, regardless of their physical activity levels.

Previous studies have linked sitting to heart disease, diabetes, and cancer, and this research now adds brain health to that list. Prolonged sitting may harm brain blood vessels, increase inflammation, and disrupt brain cell connections. What makes this study significant is its use of advanced motion sensors that tracked movement 30 times per second, providing more accuracy than self-reported activity levels. This allowed researchers to clearly distinguish between sitting, light movement, and vigorous activity.

Participants also completed cognitive assessments and underwent brain scans focusing on brain regions affected by Alzheimer's. Importantly, the study controlled for physical activity, revealing that even with regular exercise, excessive sitting can still negatively impact brain health.

How to protect your brain

With technology, smartphones, AI, and remote everything making daily life more convenient, it's no surprise that people are sitting more than ever. The average older adult spends over nine hours a day seated, according to earlier research cited in the study, and that was before the Covid-19 pandemic, which encouraged even more sedentary habits.

For those concerned about brain health, the takeaway is simple: reducing sitting time is just as important as staying active. Incorporating standing desks, regular movement breaks, and more daily activity can make a real difference. Ultimately, it's not just about fitting in a workout, it's also about what you do the rest of the day. Your brain benefits not only from exercise but also from moving more and sitting less.