Two secrets to a longer life: sleep the right amount and don’t sit all day

According to a study carried out at the University of Sydney, there are six main risk behaviours associated with early death: alcohol consumption, poor diet, inactivity, smoking, sedentary behaviour and getting the wrong amount of sleep.

The research, published in the journal PLOS Medicine, reports that for the first time in human history non-communicable diseases (those that aren’t passed from person to person) kill more people than any other cause. Preventable disease accounts for over two-thirds of the world’s annual deaths. Leading examples include cardiovascular disease, cancer and diabetes. These conditions can largely be attributed to the lifestyle risk factors identified in the study.

The researchers say that incorporating two new risk factors — prolonged sitting and an unhealthy amount of sleep — will allow clinicians to more accurately assess a person’s risk of early death. It was suggested that sitting for more than seven hours and sleeping for more than nine count as risk factors.

Avoiding these factors will raise a person’s chances of a longer life.

The researchers used the mortality registration data of 231,048 Australians who had completed a lifestyle questionnaire. They scored the six health behaviours for each participant and used the results to provide a lifestyle risk index. About a third of participants reported exposure to no risk factors; a tenth reported exposure to three or more risk factors. The index proved to be a reliable predictor of all-cause mortality.

The study finds that those most at risk are people who score highly for a combination of the separate risk factors.

The study’s lead author, Dr Melody Ding, said: ‘To examine specific patterns of lifestyle risk behaviours, 96 variables — representing all possible mutually exclusive combinations of smoking, high alcohol intake, physical inactivity, poor diet, prolonged sitting, and short/long sleep duration — were created. Short and long sleep durations were separated as two different risk factors, as their associations with mortality may be explained by different mechanisms.

‘This analysis investigated four established and two new risk factors, namely, prolonged sitting and unhealthy sleep duration, which may be added to behavioural indices or risk combinations to quantify health risk.’

The researchers say that adherence to a healthy lifestyle reduces the risk of death from all causes, and that specific combinations of behaviours may be more harmful than others.