Dementia danger rises if you sit for over 10 hours

Sitting for more than 10 hours a day increases the risk of dementia, even with regular breaks to stand and walk around, research shows.

People who sat for 15 hours a day were three times more likely to get dementia than those who sat for less than 10.

Sitting for more than 10 hours a day increases the risk of dementia, even with regular breaks to stand and walk around, research shows.

Scientists looked at 50,000 adults older than 60, measuring the time spent on activities such as driving, watching TV or working at a laptop.

They found that the risk of dementia increased significantly the longer people sat down each day beyond a 10-hour threshold.

People who sat for 15 hours a day were three times more likely to get dementia than those who sat for less than 10. It did not matter whether the 10 hours were consecutive or spread out and interspersed with activity.

The researchers said trying to offset a sedentary lifestyle by regularly standing up and taking breaks could not undo the negative impact.

David Raichlen of the University of Southern California, lead author of the study, said: “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 once you take into account the total time spent sedentary, the length of individual sedentary periods didn’t really matter.”

Professor Raichlen said office workers stuck at a computer from 9am to 5pm should be reassured that it was not necessarily harmful as long as they did not also spend two hours in the evening sitting in front of the television.

The study, published in the Journal of the American Medical Association, used data from 50,000 adults over 60 in the UK who wore Fitbit-style devices to measure movement, and who were followed for an average of six years. In this period, 414 were given diagnoses of dementia.

The average person spent about 9.5 hours a day sitting down. Compared with this, those who sat for 10 hours faced an 8 per cent increased risk, and sitting for 12 hours was linked to an increased risk of 63 per cent. Those who sat for at least 15 hours, almost all their waking hours, were three times more likely to get dementia.

The Times