Lack of exposure to natural light was considered among the reasons why some people suffer from sleep problems at night. A new study into what was earlier only anecdotal evidence shows that this is indeed true, especially in countries that have dark or cloudy winter months.
Researchers at the University of Washington in the United States say that exposure to natural light during the day, particularly in the morning and midday, could improve sleep even on cloudy winter days. They suggest that getting a good night’s rest could be as simple as spending more time outside during the day, exercising regularly and maintaining a consistent sleep schedule.
The new study, which provides interesting insights into sleep patterns of the human body, shows that not getting enough natural light during the day causes problems when it comes to getting quality sleep at night. Prior studies have shown that at least 30 minutes of exposure to natural sunlight has a significant impact on the body’s internal clock, promoting more restful sleep.
For the new study, the 500 university student participants wore wrist monitors that allowed researchers to monitor their sleep patterns throughout the four seasons. Data collated from the study showed that the students were getting about the same total amount of sleep each night despite whether it was winter or summer.
However, during the winter months, students who fell asleep late at night woke up later in the morning. On average, these students went to sleep 35 minutes later and woke up 27 minutes later on winter college days compared to summer college days. Because there is less daylight in the winter, the students’ sleep-wake pattern came as a surprise to the researchers.
The study-team surmised that students stayed up late and slept in because they did not get enough exposure to natural light during the winter months. They explained that getting natural light during the daytime advances the body’s biological clock, often referred to as circadian cycle, which regulates sleep patterns and helps make it easier to fall asleep at a reasonable time and wake up in the early morning.
The researchers admitted that a possible limitation to their study was that it was conducted at the University of Washington located in Seattle of Washington State, which is largely cloudy in winter and typically gets about 16 hours of sunlight on the summer solstice and just over 8 hours of sunlight on the winter solstice. They added that further studies in different geographical regions were needed to confirm whether natural light exposure can effectively promote sleep.
Both daytime and evening light affects the timing of a person’s biological clock. While exposure to daytime light helps promote restful sleep at night, evening light may delay the internal clock by suppressing melatonin — a hormone released in the brain at night and associated with control of the sleep–wake cycles— which then interferes with the ability to fall asleep and get good quality sleep.
According to the study, each additional hour of daytime light was linked to improvements in the circadian cycle, and that bright midday light was more effective for improving sleep than morning light. Previous studies have shown that Seasonal Affective Disorder (SAD), which usually occurs during the winter months when there is less sunlight, could be the result of light-induced circadian dysregulation. Some symptoms of SAD include emotional changes and mood shifts, including depression, difficulty sleeping, fatigue, weight gain, and social withdrawal. The new study suggests that symptoms of SAD could be improved through exposure to natural light.
Read Today's News TODAY... on our Telegram Channel click here to join and receive all the latest updates t.me/thetimeskuwait
