According to a new study, people who prefer to go to bed late and wake up later have a higher risk of dying younger.
"The increased risk of mortality associated with being an 'evening person' appears to be mainly caused by greater consumption of tobacco and alcohol. This compares to those who are clearly 'morning' people," says study author Christer Hublin.
The study, published Friday in the journal Chronobiology International, is a follow-up to a study done in 2002. The new study followed nearly 24,000 twins from 1981 to 2018.
When the study first began, each twin was asked to choose one answer from the following alternatives: I am definitely a morning person; I'm somewhat of a morning person; I am definitely an evening person; or I'm somewhat of an evening person.
Only about 10% of twins described themselves as evening people, while 33% said they sometimes preferred to stay up late. Over 29% were clearly morning people, while another 27.7% described themselves as somewhat inclined to prefer breakfasts.
For the new study, the researchers looked at the death records of a subset (8,728 participants) of the original study. After adjusting the data to account for education level, alcohol use, smoking, body mass index and sleep duration, the study found that being a person who prefers to stay up late at night and wake up later increases the risk of an early death by about 9 percent compared to people who preferred to sleep early and wake up early.
"It is known that people who stay up late at night are more likely to smoke cigarettes, alcohol and other substances," says Bhanu Prakash, a sleep specialist.
"Another problem can be the fact that those who sleep late may have to wake up early for school and work and thus end up sleeping less. It is already known that lack of sleep increases the risk of diseases," says Prakash.
Previous research has shown that people who sleep late may be at higher risk for chronic diseases. A 2022 study also found that these people are more sedentary, have lower levels of physical activity, burn less fat and are more likely to be insulin resistant.