People regularly experiencing brighter nights and darker days have higher mortality risk, suggests study

A team of biologists, medical researchers and sleep specialists from several institutions in Australia, the U.S. and the U.K. has found that people who regularly experience brighter nights and/or darker days tend to have a higher mortality risk.

In their study, published in the Proceedings of the National Academy of Sciences, the group analyzed patient data in the UK Biobank, focusing on sleep patterns and lighting.

Prior research has shown that regular interruption of the circadian rhythm can lead to a host of health problems, including an increase in premature death.

In this new effort, the research team wondered about the impact of light on the circadian cycles of people who are regularly awake at night, and by extension, their risk of dying prematurely. To find out, they accessed and analyzed data from the UK Biobank, a repository of biomedical data for hundreds of thousands of people in the U.K.

The researchers sought data from people who wore wrist devices that tracked light exposure, finding 89,000 in the database. After filtering, the test cases were whittled down to 88,905 people, most of whom were white and over the age of 62.

The researchers focused on the mortality of those that were tracked over a period of eight years, and their exposure to light at night or darkness during the day.

They found 3,750 deaths in the sample, 798 of which were associated with heart problems. They also found an association between exposure to light at night and an increased risk of dying prematurely. The increased risk was found to be most pronounced for people with heart disease.

The researchers also found that those people who were regularly exposed to more light than average during the day reduced their mortality risk. The researchers were also able to see disruptions to the circadian rhythm in people who regularly experienced light at night, which puts them at risk for a wide variety of ailments.

The research team suggests that people maintain darkness late at night and early mornings, when the circadian rhythm is most susceptible to disruption. And if possible, they should expose themselves to more light during the day.

© 2024 Science X Network