The Light of Day
On November 1st we change the clocks back to Daylight Standard Time. It is an annual reminder of the natural process that results in less daylight in the coming few months. We sometimes forget how much sunlight plays a part in our overall health. Aside from the manufacturing of vitamin D, there are other aspects to the light spectrum that researchers are just beginning to understand and this mainly centers on melatonin production.
What is Melatonin?
Melatonin is a hormone secreted by the pineal gland which is located at the base of the brain. It is secreted during the night time hours and has a great impact on our ability to sleep. Diminishing light that falls onto the eye’s retina then stimulates the pituitary to message the pineal to produce melatonin. It also acts as an antioxidant and research is now showing that it may be instrumental in helping depression, and also reducing tumors.
Daylight and Nightlight
In school you may remember that the visible light spectrum was made of different wavelengths of light and each of these wavelengths has its own color. The mnemonic ROYGBIV describes the colors from Red on one end and Violet to the other end of the light spectrum. What is interesting is that sunlight in the morning hours has a wavelength more on the blue/violet end of the spectrum and in the late afternoon sunlight has a wavelength more on the red end of the light spectrum. Science is showing that the light (blue, violet) of the morning is energizing to us, and light towards the late afternoon (red, orange, amber) is more relaxing.
For thousands of years humans evolved with a cycle of light and darkness that closely approximated about 12 hours of each per day. Even accounting for the more recent use of fire at night, it still wouldn’t have had the deleterious effect on earlier humans the way modern lights do, because fire projects an amber colored light.
Artificial light and its effect on us
All incandescent bulbs, florescent lighting, L.E.D.’s, and the light emitted from T.V.’s, computer screens and cell phones are in the blue light spectrum. Modern society’s exposure to this excessive blue light is causing health issues that are sobering. As many of you know sleep problems are a problem that has been increasing for a greater number of Americans. There are many possible reasons for this but certainly overstimulation of this blue light is part of the problem. However sleep disturbance isn’t the only consequence of artificial light.
Recent research shows that nurses who work the night shift have twice the incidence of breast cancer than those nurses who work the day shift. Additionally blind men have half the incidence of prostate cancer than sighted men and blind women have half the incidence of breast cancer than sighted women.
Coincidence? I don’t think so. There’s more. One study took rats grafted with breast cancer tumors and gave some of those rats the blood of women who were exposed only to daytime light or artificial light. Another group of rats with tumors were given blood from women that slept restfully in the dark. The results were: rats with the light exposed blood caused the tumors to grow and the blood from women that slept restfully caused the tumors to shrink.
Another study of people with bipolar symptoms, showed remarkable improvement with Dark Therapy; putting people in sunlight 12 hours per day and then total darkness the other 12 hours of the day.
Clearly the importance of the amount and type of light we get on a regular basis is related to our overall health.
For some people taking melatonin is one solution. For others, consciously making an effort to turn down lights and computers at an earlier hour is helpful. Lighting a fire if you have a fireplace, or lighting candles in lieu of lights, is another approach to helping your body unwind and relax in the evening hours.
There are other options. A website www.lowbluelights.com offers devices to help such as a nightlight, a reading light or a flashlight that has very low blue light spectrum bulbs. They also sell amber colored glasses that you can wear a few hours before bedtime to aid in the natural increase of melatonin production in your body. Also if you want your laptop or tablet to reduce the blue light spectrum as the day goes on, you can download an app at https://justgetflux.com/ that will do it gradually for you based on the time zone you live in.