A sedentary lifestyle can lead to a multitude of health issues, including metabolic disorders, cardiovascular disease and cancer. It can also affect longevity. Researchers have now found that sitting for more than 10 hours a day increases the risk of dementia in people aged above 60.

The latest study, published in Jama Network, suggests that total sedentary time, irrespective of the pattern in which they are accumulated daily, elevates the risk of dementia, the disorder that affects memory and thinking.

"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. We found that once you take into account the total time spent sedentary, the length of individual sedentary periods didn't really matter," study author David Raichlen said in a news release.

Researchers used data from over 50,000 participants of the U.K. Biobank, a large-scale biomedical database, to evaluate the possible links between sedentary time and dementia risk. All the participants, who were above 60 years of age, were asked to wear accelerometers to measure their movements. None of them were diagnosed with dementia at the start of the study.

The team used a machine-learning algorithm to analyze the dataset and classified the participants based on the intensity of physical activity. After around six years, there were 414 cases of dementia.

"Our latest study is part of our larger effort to understand how sedentary behavior affects brain health from multiple perspectives. In this case, wearable accelerometers provide an objective view of how much time people dedicate to sedentary behavior that complements our past analyses," Raichlen said.

The latest study suggests that although high amounts of sedentary time increase dementia risk, lower levels of sedentary behavior, like sitting for less than 10 hours a day, do not elevate the risk.

"We were surprised to find that the risk of dementia begins to rapidly increase after 10 hours spent sedentary each day, regardless of how the sedentary time was accumulated. This suggests that it is the total time spent sedentary that drove the relationship between sedentary behavior and dementia risk, but importantly lower levels of sedentary behavior, up to around 10 hours, were not associated with increased risk," said Gene Alexander, another study author.

"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," Raichlen added.