Credit: Pixabay/CC0 Public domain
A team of biologists, medical researchers and sleep specialists from several institutions in Australia, the United States and the United Kingdom found that people who regularly experience brighter nights and/or darker days tend to have a higher risk of mortality.
In their study, published in the Proceedings of the National Academy of Sciences, The group analyzed patient data from the UK Biobank, focusing on sleep patterns and lighting.
Previous research has shown that regular disruption of the circadian rhythm can lead to a host of health problems, including an increase in premature deaths.
In this new effort, the research team questioned 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 covering hundreds of thousands of people in the United Kingdom.
The researchers searched for data from people wearing wrist devices that track light exposure, and found 89,000 in the database. After filtering, the test cases were reduced to 88,905 people, most of whom were white and over the age of 62.
The researchers focused on mortality of people followed over an eight-year period and whether they were exposed 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 more pronounced in people with heart disease.
Researchers also found that people who were regularly exposed to more light than average during the day reduced their risk of mortality. Researchers have also noted disruptions in the circadian rhythm in people who are regularly exposed to light at night, putting them at risk for a wide variety of diseases.
The research team suggests that people maintain darkness late at night and early in the morning, when the circadian rhythm is most likely to be disrupted. And if possible, they should expose themselves to more light during the day.
More information:
Daniel P. Windred et al, Brighter nights and darker days predict higher mortality risk: a prospective analysis of personal light exposure in >88,000 individuals, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2405924121
© 2024 Science X Network
Quote: People who regularly experience brighter nights and darker days have a higher mortality risk, study suggests (October 17, 2024) retrieved October 17, 2024 from
This document is subject to copyright. Except for fair use for private study or research purposes, no part may be reproduced without written permission. The content is provided for informational purposes only.
