According to a new study in the Journal of Affective Disorders, natural daytime light exposure may impact mood and the circadian system, as well as increase sleep quality.
The study was derived from the examination of more than 500,000 adults residing in the United Kingdom as part of the UK Biobank cohort.
The adult participants were between the ages of 37 and 73.
“Light has powerful effects on mood, sleep, and the circadian system. Humans evolved in an environment with a clear distinction between day and night, but our modern environments have blurred this distinction,” the authors of the study wrote in their findings.
“Here we examine the cross-sectional and longitudinal associations of time spent in daytime outdoor light with mood, sleep, and circadian-related outcomes.”
The study’s results show that the participants spent an average of 2.5 daylight hours outdoors each day, with each additional hour spent outdoors attributed to a lower risk of depressive disorders, increased mood, and lower neuroticism.
The study also uncovered increased sleep quality and less tiredness among the UK Biobank participants.
“In this study, we observed that greater time spent in outdoor light was associated with better mood outcomes, better quality sleep, and ease of wakening,” said one author of the study in a press release.
“These results may be explained by the impacts of light on the circadian system and the direct effects of light on mood centers in the brain.”