Night owls face the risk of earlier death‚ study concludes

Night owls have a higher risk of dying sooner than those who go to bed early.

A study involving nearly half-a-million people found that those who stayed up late and had trouble dragging themselves out of bed in the morning faced a 10% higher risk of death during the six-and-a-half-years they were monitored.

Participants‚ who were aged between 38 and 73‚ classified themselves as a “morning type” or “evening type”. Those who identified as definite morning types were on average older‚ more likely to be women and non-smokers‚ and less likely to be white.

Night owls were more likely to have a wide variety of diseases‚ including diabetes and psychological‚ neurological‚ respiratory and gastrointestinal disorders‚ according to findings published on Thursday in the journal Chronobiology International.

The researchers said their study proved staying up later had negative effects on people’s health.

“It could be that people who are up late have an internal biological clock that doesn’t match their external environment‚” said co-lead author Kristen Knutson‚ associate professor of neurology in the medical school at Northwestern University in the US.

“It could be psychological stress‚ eating at the wrong time for their body‚ not exercising enough‚ not sleeping enough‚ being awake at night by yourself‚ maybe drug or alcohol use.

“There are a whole variety of unhealthy behaviours related to being up late in the dark by yourself.”

Malcolm von Schantz‚ a professor of chronobiology at the University of Surrey in the UK‚ which was involved in the study‚ said: “This is a public health issue that can no longer be ignored.

“We should discuss allowing evening types to start and finish work later‚ where practical. And we need more research about how we can help evening types cope with the higher effort of keeping their body clock in synchrony with sun time.”

Knutson said night owls could improve their chances of living longer by ensuring their were exposed to light early in the morning but not at night. She recommended:

- Keeping a regular bedtime;

- Being regimented about adopting healthy lifestyle behaviours;

- Recognising that the timing of when you sleep matters; and

- Doing things earlier and being less of an evening person as much as you can.

“If we can recognize these chronotypes are‚ in part‚ genetically determined and not just a character flaw‚ jobs and work hours could have more flexibility for owls‚” she said.

“They shouldn't be forced to get up for an 8am shift. Make work shifts match people’s chronotypes. Some people may be better suited to night shifts.”

In future research‚ Knutson and colleagues want to test an intervention with night owls to get them to shift their body clocks to adapt to an earlier schedule. “Then we’ll see if we get improvements in blood pressure and overall health‚” she said.