You might want to rethink your next sleep-in.
According to a study published last week by the University of Sydney, sleeping more than nine hours could increase your risk of an early death.
Over six years, researchers looked at links between lifestyle factors and mortality rates, and those who regularly overslept were noted to have a 44 per cent increased risk of dying prematurely, while those sleeping fewer than seven hours had a 9 per cent increase.
One of the authors, Associate Professor Emmanuel Stamatakis, told Fairfax Media one of the possible explanations could be ‘reverse causality’.
“Long sleeping times could be indicative of an underlying, undiagnosed disease,” explained Dr Stamatakis.
But what he believes could be the more plausible explanation is actually linked to quality of sleep, rather than the number of hours.
“In the survey, people were asked: ‘How long did you sleep?’ This most likely elicits an answer to the question: ‘How long were you in bed?’,” which he says, tells us nothing about the quality of sleep they experienced.
“So, reported long sleep duration could in fact be indicative of fragmented, restless and poor-quality sleep,” which is what Dr Stamatakis believes is the most likely connection to increased mortality.
One of the largest studies of its kind to date, researchers commenced their observations in 2006, which included more than 200,000 people over the age of 45 and covers 11 per cent of New South Wales’ target population.
During the study, a third of all deaths were attributed to unhealthy behaviours. Aside from oversleeping, other emerging trends linked to increased mortality included smoking, poor diet, excessive alcohol consumption, along with inactivity and prolonged sitting.
And if you happen to identify with a combination of these dangerous behaviours you won’t be surprised to hear that your risk of death increases again.
Those involved in the study who generally identified with all six categories were five times more likely to die prematurely.
So the moral of the study? As health professionals have been saying for years: don’t smoke, keep active, eat healthy, drink moderately, and sleep well.
The study was published in PLOS Medicine.
Source: The Sydney Morning Herald
