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
Abstract
Increased sedentary behavior is associated with neurodegeneration and worse cognition in older adults over a 7-year period despite high levels of physical activity
INTRODUCTION
Sedentary behavior may be a modifiable risk factor for Alzheimer’s disease (AD). We examined how sedentary behavior relates to longitudinal brain structure and cognitive changes in older adults.
METHODS
Vanderbilt Memory and Aging Project participants (n = 404) completed actigraphy (7 days), neuropsychological assessment, and 3T brain MRI over a 7-year period. Cross-sectional and longitudinal linear regressions examined sedentary time in relation to brain structure and cognition. Models were repeated testing for effect modification by apolipoprotein E (APOE) ε4 status.
RESULTS
In cross-sectional models, greater sedentary time related to a smaller AD-neuroimaging signature (β = -0.0001, p = 0.01) and worse episodic memory (β = -0.001, p = 0.003). Associations differed by APOE-ε4 status. In longitudinal models, greater sedentary time related to faster hippocampal volume reductions (β = -0.1, p = 0.008) and declines in naming (β = -0.001, p = 0.03) and processing speed (β = -0.003, p = 0.02; β = 0.01, p = 0.01).
DISCUSSION
Results support the importance of reducing sedentary time, particularly among aging adults at genetic risk for AD.
