Brain News You Can Use (September 2013)

By Gail Sanders Durgin, Ph.D., BCN-Fellow, QEEGT

Effects of Light on Your Health

Did you know that the colors of light you are exposed to can have an effect on your health and your mood? Does watching TV late at night or using a tablet in bed affect your ability to sleep?

The effects of light on the circadian rhythm or the internal clocks of living organisms was first seen in 1958. In the years since, the effects of light on humans has been studied in more detail. In particular, blue light has the strongest effect on the circadian rhythms or the internal clocks of people. Researchers are now finding more evidence that an out-of-phase circadian rhythm is a health hazard. Dr. Dieter Kuna states, "A growing body of evidence suggests that a desynchronization of circadian rhythms may play a role in various tumoral diseases, diabetes, obesity, and depression." He also states that shift workers who experience the most internal desynchronization and have an increased risk of a number of diseases that include cardiovascular disease and cancer.

While it is not clear why nighttime light is so bad for us, we do know that light exposure suppresses the secretion of melatonin which influences circadian rhythms. Even a small amount of light, as the amount of light produced by a table lamp, can change the circadian rhythm and the amount of melatonin we produce. The amount of light we are exposed to at night is part of the reason that people don't get enough sleep at night. Short sleep at night has been linked to the increase risk for depression, diabetes and cardiovascular problems. Any type of light can affect the secretion of melatonin, but blue light in particular has a more powerful effect. For example, blue light suppresses melatonin production for twice as long as green light. Red lights have the least ability to shift circadian rhythm and suppress melatonin. Night lights should be dim red lights because they have the least effect on sleep.

Blue light also is becoming more common in our environment. The light bulbs we use are increasingly becoming fluorescent and LED. While these bulbs are more energy efficient, they produce more blue light than old-fashioned incandescent lightbulbs.

Other common sources of blue light are the number of electronic screens we are exposed to, especially portable digital devices. Newer televisions produce more blue light than older tube model. More disruptive than television are the number of portable devices we use as laptops, tablets and smartphones. The degree to which the circadian rhythm is disturbed is influenced by how bright the light is, how far the device is from the eyes and the colors of the light being emitted. Since these small devices are held close to the face and are often used in bed, they could have the largest effect on the ability to produce melatonin and fall asleep, delaying sleep patterns.

Lack of sleep can affect concentration, memory, and alertness which could lead to problems at school and at work.

Suggestions for reducing these problems include:

• Use red or amber light, which have the least effect on sleep, for night lights.
• Avoid looking at bright screens for two to three hours before bed, especially for children. If you can't avoid looking at screens, use blue blocking screens on TV's or tablets if you use electronic devices too close to bedtime.
• Purchase blue-blocking glasses to use if using electronic devices late in the evening or if you work a night shift job. Blue blocking glasses and screens can be obtained from online stores on the internet.
• Get lots of bright light during the day which will help keep your circadian rhythm regulated and improve mood and alertness.

Note from author: Sleep in a growing problem for children and adults. Many times, environmental changes can reduce sleep issues. For some people, poor sleep is the result of EEG patterns that are deregulated due to a number of causes. Neurofeedback has been shown to be very helpful in reducing sleep problems for adults and children.

Gail Sanders Durgin, Ph.D. has been providing neurofeedback and biofeedback at Neurofeedback Associates Inc since 2000. She previously worked in mental health and developmental disabilities services for 18 years. Dr. Durgin offers the most advanced treatment services in the field in order to offer individualized client centered solutions to improve brain and life performance.

Published in Natural Triad, September, 2013