Night owls have a slightly higher risk of developing unhealthy habits and may possibly die earlier than those who rise early, according to a new study.
The research, published recently in the journal Chronobiology International, assessed data on nearly 23,000 twins gathered over the course of over 37 years in Finland.
Scientists, including those from the University of Helsinki, assessed the impact of an individual’s chronotype – the body’s natural inclination to sleep at a certain time – on their health.
The findings suggested there is little direct contribution of chronotype to mortality.
However, researchers found that an increased risk of death linked with being a clearly “evening” person – people who stay up late at night and go to bed later to wake up late – was accounted for by their larger consumption of tobacco and alcohol.
There is growing evidence that sleep duration and quality, and night shift work affect health with previous studies finding that night owls have a higher risk of disease, especially heart problems.
The new research followed 22,976 men and women aged 24 years from 1981 to 2018.
Individuals were asked to pick from four possible responses: “I am clearly a morning person”; “I am to some extent a morning person”; “I am clearly an evening person”; “I am to some extent an evening person”.
Participants were followed up in 2018 to find if any of them had died.
Researchers also took into account the participants’ education, daily alcohol consumption, smoking status and quantity, BMI, and sleep duration.
The results revealed that 7,591 of the twins identified as “to some extent” and 2,262 as “definite” evening types while for morning types, the numbers were 6,354 and 6,769, respectively.
Night owls drank or smoked more compared to morning types, and the “definite” evening types were also less likely to report getting eight hours of sleep.
Over 8,700 of the nearly 23,000 participants had died by 2018.
The findings suggested that the chance of dying from any cause was nine per cent higher among definite night owls as compared to early birds.
However, smoking and alcohol largely caused these deaths, not chronotype, scientists said, adding that they could relate their findings to society as a whole.
“We have known for a long time that those who have an evening type preference are more likely to be heavier drinkers, have alcohol use disorder, and are also more likely to use other substances including tobacco,” sleep medicine specialist Bhanu Prakash Kolla told CNN.
