People who struggle to get up in the morning may also be more likely to die early, new research has found 
Credit: Henry Steadman 

Night owls, individuals who stay up late and struggle to get out of bed in the morning, are more likely to die sooner than morning larks, the first study into their death rates has found.

New research by the University of Surrey and Northwestern University in the US found that people who naturally stay up late were 10 per cent more likely to die within the six and a half year study period compared to those who preferred the morning.

Researchers say that the ongoing stress of operating in a traditional 9-5 society was having a huge impact on millions of people and could be shortening their lives.

"This is a public health issue that can no longer be ignored," said Malcolm von Schantz, a professor of chronobiology at the University of Surrey.

"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."

The research, involved nearly 500,000 Brits aged between 38 and 73, and found that around nine per cent considered themselves evening people, while 27 per cent identified as morning types.

If extrapolated to the entire population of the Britain it would mean around 5.8 million people were at greater risk of early death because they were out of sync with the environment.

Previous studies in this field have focused on the higher rates of metabolic dysfunction and cardiovascular disease, but this is the first to look at mortality risk.

"Night owls trying to live in a morning lark world may have health consequences for their bodies," said co-lead author Kristen Knutson, associate professor of neurology at Northwestern University Feinberg School of Medicine based in Chicago.

"It could be that people who are up late have an internal biological clock that doesn't match their external environment," said Dr Knutson.

"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 behaviors related to being up late in the dark by yourself."

In the new study, scientists found owls had higher rates of diabetes, psychological disorders and neurological disorders.

But the team has previously shown that whether someone is an owl or a lark is half genetic and half environment, meaning there may be ways to keep body clock issues under control.

"You're not doomed," added Dr Knutson.”Part of it you don't have any control over and part of it you might."

The team recommends that night owls can help themselves by trying to become exposed to light early in the morning and not at night. Keeping regular bedtimes, maintaining a healthy lifestyle and trying to do tasks earlier in the day can help to reset circadian rhythms.

In future studies, the researchers want to test an intervention with 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.

"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.

"They shouldn't be forced to get up for an 8 a.m. shift. Make work shifts match peoples' chronotypes. Some people may be better suited to night shifts."

The study was published in the journal Chronobiology International.