“Many of us are familiar with the common advice to break up long periods of sitting by getting up every 30 minutes or so to stand or walk around. We wanted to see if those types of patterns are associated with dementia risk,” said study author, Dr. David Raichlen, Professor of Biological Sciences and Anthropology at the University of Southern California, in a press release.
For the research, the researchers analyzed data from 49, 841 adults aged 60 years and older from the UK Biobank study. The participants did not have dementia at the beginning of the study. They were asked to wear a wrist accelerometer to measure their daily activity levels and were followed for an average of 6.72 years. Over the period, participants spent an average of 9.27 hours per day sitting, and 414 individuals were diagnosed with dementia.
Ultimately, the researchers found that dementia risk increases rapidly after 10 hours spent sitting per day, regardless of how and when sitting behavior is accumulated. They noted that the findings suggest total sitting time per day drives the relationship between sedentary behavior and dementia risk, but that up to around 10 hours of sedentary behavior daily is not linked to a higher risk.
“This should provide some reassurance to those of us with office jobs that involve prolonged periods of sitting, as long we limit our total daily time spent sedentary,” said Prof Raichlen.
The researchers noted that their findings complement previous analyses that used self-reported health data to investigate how some types of sedentary behavior- like sitting or watching TV- affect dementia risk more than others. They noted, however, that further research is needed to establish whether a causal link exists between sedentary behavior and dementia, and whether physical activity can reduce dementia risk.
Sources: Neuroscience News, JAMA Network
