Over 6 million Americans are impacted by Alzheimer’s disease, and researchers from Vanderbilt University Medical Centre 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: The Journal of the Alzheimer's Association*, researchers found that increased sedentary behaviour, time spent sitting or lying down, in ageing 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 Centre, and co-authored by Angela Jefferson, PhD, professor of Neurology and founding director of the Vanderbilt Memory and Alzheimer’s Centre at VUMC.

The team of researchers examined the relationship between sedentary behaviour and neurodegeneration among 404 adults aged 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. “Minimising 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 ageing 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.”