by Kimberly Allen, RN
A recent sleep study in Great Britain revealed that when it comes to getting a good night’s rest, not all times of the year are equal. The study looked at the sleep habits of 21,000 adults and concluded that people require approximately 8 minutes more to fall asleep and are awake approximately 10 minutes more during the night in February than in March. So what is it that causes this disparity? There are numerous theories surrounding this issue. Many believe the shorter days and longer nights as well as a heated environment all play a role.
Though this survey only covered the months of February and March, there have been other studies of sleep patterns in winter vs spring/summer. One study compared the sleep patterns in the winter months in 2 countries, one that is in the north and has a significant seasonal change and another that is near the equator and has a minimal seasonal change. They found that in the northern country there were numerous alterations found including insomnia which brings along it’s friends fatigue and moodiness during the winter months. However, in the country near the equator there were no seasonal differences found in the sleep patterns. This study basically indicates maybe a little more dramatically what other studies have shown, that the amount of sunlight available plays a significant role in our sleep patterns.
So why is sunlight so important to our sleep? Our body’s produce a hormone called melatonin that regulates our sleep – wake cycle. The amount of melatonin your body produces is directly related to sunlight. Before electricity changed the night people got more sleep at night because their cyclic patterns were more in tune with the rising and setting of the sun. Electricity has extended our ability to continue activities long after sunset. During the summer month our melatonin production occurs slightly earlier than in the winter months. Also, exposure to sunlight early in the morning tends to set our internal biological clock altering the timing of our sleep window.
On the other side of melatonin production is the production of serotonin. While the melatonin gives you a good night sleep serotonin helps you wake up feeling refreshed and ready to go. So how does our body know when to switch from producing melatonin to serotonin? There are certain proteins in our bodies called cryptomes that are highly sensitive to the blue light that is in dawn and dusk. These proteins are a significant part of our circadian rhythms. They are in our skin and eyes which allows our body to detect sunlight, even if you cover your eyes. These proteins tell the body when to switch from producing serotonin to melatonin when it detects the sunlight is diminishing.
Many experts also believe that the effects of being inside and central heating systems also play a role in altering our sleep patterns in the winter. One problem is that while it’s bitter cold and you can hear the wind whining outside it always feels good to add that extra log to the fire or turn that thermostat up a notch or two it can significantly impact your sleep. Most experts will tell you that you will sleep better in a cool room. Optimal temperature for sleep usually ranges between 68 – 72F. On the flip side for those trying to save on heating expenses having the environment too cold can also prevent you from sleeping. And your body doesn’t get much rest because it’s working to stay warm. Also during the winter months the air inside becomes stale with less oxygen which make you sleepy while at the same time inhibiting sleep.
Exercise has also been found to play a role in how well you sleep during the winter. Many people significantly reduce their physical activity in the winter due to the cold and harsh conditions.
Kimberly Allen is a registered nurse with an AND in nursing. She has worked in ACF, LCF and psychiatric facilities, although she spent most of her career as a home health expert. She is now a regular contributor to HealthAndFitnessTalk.com, dispensing advice and knowledge about medical issues and questions. You can reach her with any comments or questions at firstname.lastname@example.org.