Night owls" - the people who like to stay up late and have trouble dragging themselves out of bed in the morning -have a higher risk of dying sooner than "larks," people who have a natural preference for going to bed early and rise with the sun, according to a new study from Northwestern Medicine and the University of Surrey in the United Kingdom (UK).
The study, on nearly half a million participants in the UK Biobank Study, found owls have a 10 percent higher risk of dying than larks. In the study sample, 50,000 people were more likely to die in the 6½ -year period sampled.
"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.
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.
"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."
"It could be that people who are up late have an internal biological clock that doesn't match their external environment," Knutson said. "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."
One way to shift your behavior is to make sure you are exposed to light early in the morning but not at night, Knutson said. 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.
The study was supported by the University of Surrey Institute of Advanced Studies Santander fellowship and the National Institute of Diabetes and Digestive.