AI Discovers Connection Between Over 10 Hours of Daily Sitting and Increased Dementia Risk

Prolonged sitting poses a significant risk for developing dementia, according to groundbreaking research conducted by scientists at the University of Southern California (USC) and the University of Arizona. Utilizing advanced machine learning techniques, researchers explored the critical link between brain aging and a sedentary lifestyle, leading to some revealing findings.

The study revealed that the total daily time spent sitting is just as crucial as the duration of individual sitting sessions. Alarmingly, the average American is sedentary for approximately 9.5 hours each day. The research, published in the prestigious JAMA (Journal of the American Medical Association), indicated that individuals over the age of 60 who engage in sedentary behaviors for over 10 hours daily face a markedly heightened risk of developing dementia.

The data analyzed in the study were sourced from the U.K. Biobank sub-study, which involved more than 100,000 adults who wore accelerometers—devices worn on the wrist to track movement—over the course of an entire week. The focus centered on 50,000 adults aged 60 and older who had not yet been diagnosed with dementia at the study’s outset.

Employing a sophisticated machine learning algorithm, researchers categorized the applicants' behaviors based on varying levels of physical activity. This model could effectively differentiate between activities such as sleeping and various forms of sedentary behavior, providing scientists with invaluable objective data to assess the impact of prolonged inactivity.

In a follow-up period averaging six years, the researchers meticulously examined death registries and hospital records to identify cases of dementia, discovering 414 confirmed cases within the cohort. In their analysis, the scientists adjusted their statistical methods to account for numerous factors potentially influencing brain health, including demographics like race, ethnicity, genetics, chronic medical conditions, educational background, age, and gender, alongside lifestyle choices such as diet, alcohol use, physical activity, and mental health.

Looking ahead, the research team encourages future investigations to establish causality and determine whether adopting a more active lifestyle could mitigate the risk of dementia. Gene Alexander, a professor of psychology and psychiatry at the Evelyn F. McKnight Brain Institute at the University of Arizona and part of the Arizona Alzheimer’s Disease Research Center, expressed surprise at the findings. “Our results indicate that the risk of dementia begins to rise sharply after spending more than 10 hours each day being sedentary, irrespective of how that time is accumulated," he explained. "This suggests that the total amount of sedentary time is a significant factor influencing the relationship between inactivity and dementia risk. However, it is noteworthy that lower levels of sedentary behavior—up to around 10 hours—were not linked to an increased risk.”

This enlightening study underscores the importance of understanding how prolonged periods of inactivity can affect cognitive health, particularly in older adults.