Sitting for Hours May Shrink the Brain

Summary: Prolonged sedentary behavior in adults over
50 is linked to cognitive decline and brain shrinkage in regions
vulnerable to Alzheimer’s disease. Even among those who exercise
regularly, spending more time sitting was associated with worse
cognitive outcomes.

The effect was strongest in individuals
carrying the APOE-e4 gene, a major genetic risk factor for Alzheimer’s.
These findings suggest that breaking up sedentary time throughout the
day may be a key strategy for protecting brain health and reducing
Alzheimer’s risk, especially in genetically vulnerable individuals.

Key Facts:

• Independent of Exercise: More sitting led to cognitive decline even in regular exercisers.
• Genetic Risk Factor: Effects were more pronounced in APOE-e4 carriers.
• Brain Impact: Sedentary behavior was associated with brain shrinkage over 7 years.

Source: Vanderbilt University

Over
6 million Americans are impacted by Alzheimer’s disease, and
researchers from Vanderbilt University Medical Center and the University
of Pittsburgh are discovering how lifestyle habits can impact the
likelihood of developing the disease.

According to a new research study published in Alzheimer’s & Dementia,
researchers found that increased sedentary behavior, time spent sitting
or lying down, in aging adults was associated with worse cognition and
brain shrinkage in areas related to risk for developing Alzheimer’s
disease.

The research study was led
by Marissa Gogniat, PhD, assistant professor of Neurology at Pitt and
former postdoctoral fellow at the Vanderbilt Memory and Alzheimer’s
Center, and co-authored by Angela Jefferson, PhD, professor of Neurology
and founding director of the Vanderbilt Memory and Alzheimer’s Center
at VUMC.

The team of researchers examined the relationship between
sedentary behavior and neurodegeneration among 404 adults age 50 and
older.

Study participants wore a watch that measured their
activity continuously over the span of a week. Their sedentary time was
then related to their cognitive performance and brain scans captured
over a seven-year follow-up period. 

Participants who spent more
time sedentary were more likely to experience cognitive decline and
neurodegenerative changes regardless of how much they exercised. 

These conclusions were stronger in participants who carried the APOE-e4 allele,
a genetic risk factor for Alzheimer’s disease, suggesting that reducing
sedentary time may be especially important for older adults who are at
increased genetic risk for Alzheimer’s disease.

“Reducing your
risk for Alzheimer’s disease is not just about working out once a day,”
said Gogniat. “Minimizing the time spent sitting, even if you do
exercise daily, reduces the likelihood of developing Alzheimer’s
disease.”

“It is critical to study lifestyle choices and the
impact they have on brain health as we age,” said Jefferson, who holds
the Herbert O. and Vineta Christopher Directorship. 

“Our study
showed that reducing sitting time could be a promising strategy for
preventing neurodegeneration and subsequent cognitive decline.

“This
research highlights the importance of reducing sitting time,
particularly among aging adults at increased genetic risk for
Alzheimer’s disease. It is critical to our brain health to take breaks
from sitting throughout the day and move around to increase our active
time.”

Funding: The study was funded by the Alzheimer’s Association and the National Institute on Aging.

About this sedentary behavior and Alzheimer’s disease research news

Author: Craig Boerner
Source: Vanderbilt University
Contact: Craig Boerner – Vanderbilt University
Image: The image is credited to Neuroscience News

Original Research: Open access.
“Increased
sedentary behavior is associated with neurodegeneration and worse
cognition in older adults over a 7-year period despite high levels of
physical activity” by Marissa Gogniat et al. Alzheimer’s & Dementia