According to a new study published in the journal Chronobiology International, ‘night owls’ have a 10% higher risk of dying than ‘larks.’
Night owls have 10% higher risk of dying than morning counterparts. Image credit: Sasin Tipchai.
“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,” said co-lead author Professor Malcolm von Schantz, from the University of Surrey.
“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.”
“It could be that people who are up late have an internal biological clock that doesn’t match their external environment,” added co-lead author Dr. Kristen Knutson, from the Northwestern University Feinberg School of Medicine.
“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.”
The scientists’ objective was to test the hypothesis that being a ‘night owl’ is associated with increased mortality in a large cohort study, the UK Biobank.
Their analysis included 433,268 adults aged 38-73 at the time of enrolment and an average 6.5-year follow-up.
They adjusted for the expected health problems in night owls and still found the 10% higher risk of mortality.
“Mortality risk in night owls may be due to behavioral, psychological and physiological risk factors, many of which may be attributable to chronic misalignment between internal physiological timing and externally imposed timing of work and social activities,” the researchers said.
In future research, Professor von Schantz and Dr. Knutson want to test an intervention with owls to get them to shift their body clocks to adapt to an earlier schedule.
“Can night owls become larks? Genetics and environment play approximately equal roles in whether we are a morning or a night type, or somewhere in between,” they said.
“Owls trying to live in a morning lark world may have health consequences for their bodies.”
“You’re not doomed. Part of it you don’t have any control over and part of it you might,” Dr. Knutson said.
“One way to shift your behavior is to make sure you are exposed to light early in the morning but not at night. Try to keep a regular bedtime and not let yourself drift to later bedtimes. Be regimented about adopting healthy lifestyle behaviors and recognize the timing of when you sleep matters. Do things earlier and be less of an evening person as much as you can.”
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Kristen L. Knutson & Malcolm von Schantz. Associations between chronotype, morbidity and mortality in the UK Biobank cohort. Chronobiology International, published online April 11, 2018; doi: 10.1080/07420528.2018.1454458
