Study Reveals Benefits of Sunlight

Sunlight may improve sleep, elevate mood, and reduce insomnia
By Sarah Cownley
Sarah Cownley
Sarah Cownley
November 1, 2021 Updated: November 1, 2021

Sleep disorders are pervasive and approximately one in three adults suffer from mild insomnia. As stress levels rise around the world, insomnia is becoming more prevalent in adults. But a new study led by Monash University has found that getting enough natural sunlight each day could help to reduce insomnia and improve mood.

The study published in the Journal of Affective Disorders included more than 400,000 participants from the UK biobank program. It was found that a lack of daytime light exposure was a risk factor for poor mood, insomnia, and depressive symptoms.

Researchers noted that most messaging around health and light is focused on avoiding light at night. Previous research has found that light during nighttime can disrupt the body’s clock, also known as circadian rhythm. This study helps to highlight the importance of getting enough daylight to ensure the body can function optimally.

Circadian Rhythm

Circadian rhythm is a natural internal process that regulates the sleep–wake cycle. It repeats roughly every 24 hours and can help guide the body to let it know when to sleep and when to be awake. This cycle is vital in helping the body rest and regain energy lost from being awake and performing daily activities.

In an article on Monash University’s website, study co-author Sean Cain said, “In this study, we observed that the greater time spent in outdoor light during the day was associated with fewer depressive symptoms, lower odds of using antidepressant medication, better sleep, and fewer symptoms of insomnia.”

The reduction of these symptoms may be explained by the effect of light on circadian rhythm and the direct effect that sunlight creates on mood centers in the brain.

People tend to spend most waking hours in artificial lighting conditions and relatively bright nighttime light exposure. By making minor adjustments to a daily routine, some may improve their sleep, mood, and energy levels.

Researchers concluded the study by noting that insufficient exposure to daytime light could be a critical factor that contributes to poor sleep outcomes and depressive disorders. They suggest simple advice for everyone; when the sun is out, get as much light as you can, but after it sets, keep your environment dark. That’s good advice, but likely easier said than done in northern climates, with radical shifts in daylight length between summer and winter.

This study helps to show the importance of daytime light. Researchers recommend exposure to bright lights first thing in the morning and spending time outdoors, getting enough sunlight during daytime hours. Exposure to blue light should be avoided, especially at night, and bright lights at night should be turned off, screen time limited, and lights in the bedroom blocked off.

By correcting your circadian rhythm, you will feel more awake during the day and more sleepy at night. As this study also suggests, you can help boost mood and reduce episodes of insomnia.

Sarah Cownley earned a diploma in nutritional therapy from Health Sciences Academy in London. She enjoys helping others by teaching healthy lifestyle changes through her personal consultations and with her regular contributions to the Doctors Health Press. This article was originally published on Bel Marra Health.