Strong association shown between being sedentary and dementia risk

Based on data from nearly 50,000 adults in the United Kingdom, NIA-funded researchers have shown an association between dementia risk and daily sedentary behavior. Though the study cannot establish a causal link, it does support the idea that more time spent not moving — such as sitting while watching TV, working on a computer, or driving — may be a risk factor for dementia. The findings were published in JAMA.

A research team led by scientists at the University of Southern California and the University of Arizona looked at data from the UK Biobank. Focusing on adults 60 years and older who wore devices that measure movement, called accelerometers, the researchers used machine learning to predict what patterns of accelerometry data truly predicted sedentary behavior. They then used hospital and death registry data to determine which of these participants developed dementia in the following years.

Median duration of sedentary behavior was just over nine hours per day, similar to results of studies on Americans. The analysis also indicated association between sedentary time and dementia risk. Most notably, the risk for dementia increased greatly for adults who were sedentary more than 10 hours a day.

Though this study did not test the role of physical activity and dementia risk, UK Biobank data has also been used to show a healthy lifestyle is associated with lower risk of dementia. These recent results support the need to study whether there is a causal link between sedentary time and dementia risk and what aspect of sedentary behavior increases that risk.

This research was supported in part by NIA grants P30AG072980, P30AG019610, R56AG067200, R01AG064587, and R01AG072445.

These activities relate to NIH’s AD+ADRD Research Implementation Milestone 1.B, “Quantify the exposome in existing and new AD cohorts to gain a more precise measure of environmental exposure factors and their relationship to AD risk and individual trajectories of disease progression.”

Reference: Raichlen DA, et al. Sedentary behavior and incident dementia among older adults. JAMA. 2023;330(10):934–940. doi:10.1001/jama.2023.15231.