People who sleep late and have difficulty waking up in the morning are more likely to die prematurely compared with early risers, findings of a new study have revealed.
It isn't the first research to suggest the unwanted consequences of habitually staying up late. Earlier studies have already found higher rates of metabolic problems and cardiovascular diseases in people who are active at night.
Night Owls Have 10 Percent Increased Risk Of Dying Early
For the new study, which was published in the journal Chronobiology International on April 11, researchers tracked around 433,000 individuals over a period of 6.5 years. They found that people who identified themselves as "definitive evening type" have 10 percent increased risk of all-cause mortality compared with those who identified themselves as "definite morning types."
The researchers did not look at the specific causes of death, but they think that night owls are at higher risk of developing cardiovascular disease and certain cancer types such as breast cancer and prostate cancer.
Study researcher Kristen Knutson, from Northwestern's Feinberg School of Medicine, said that the night owls tend to suffer from neurological disorders, diabetes, psychological disorders, gastrointestinal disorders, and respiratory disorders.
Knutson said that one problem night owls face is living in the morning lark work. As a result, the mismatch between their body clock and their external world impacts their health in the long run, particularly if they have an irregular schedule.
"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," Knutson said.
Not Doomed
The researchers said that genetics and environment contribute to a person being a morning or a night person, which means that night owls can work their way to becoming morning larks.
Researchers said that one way to shift behavior is through exposure to light in the morning rather than in the evening. Keeping a regular bedtime, adopting healthy lifestyle and behaviors, recognizing the importance of the timing of sleep, and doing things earlier can also help.
Knutson and colleagues also said that the society can help. Employers, for instance, can provide a more suitable work schedule to reflect the internal clock preference of their employees.
"Understanding the link between chronotype and mortality could lead to the development of additional behavioural strategies to mitigate risk associated with being an evening type. Strategies could include therapies that target the circadian system and tailoring schedules to suit individual chronotype whenever possible," the researchers wrote. "These novel therapies have the potential to critically improve not only well-being and health but even life expectancy of evening types."
