Gotta get some sleep!

Sleep is one of the foundations of health, along with diet, exercise, and breath. Its contributions to our health are often undervalued in our society. At different times in our lives competing needs to be entertained or productive or present for little ones take precedence over sleep.

Being better-rested helps memory, mood, and weight control and lowers stress and inflammation. We are less accident-prone and tend to make better decisions when we are well-rested.

Changes in our environment have affected the sleep of many of us at every age. Darkness is the signal for our bodies to release melatonin, a hormone that signals the brain to become sleepy. Light inhibits the release of this hormone. With the invention of electric light we had an effective way to turn night into day, disrupting our normal circadian rhythms. Rather than being a time for rest, night suddenly became a time when we could be up and about.

What happens when circadian rhythms are substantially disrupted from the norm? Studies done on people who work the night shift have found those workers are at higher risk of cardiovascular disease, weight gain, diabetes, and mood disorders. While some people can adjust to a night schedule, for many it is a stress to which the body never fully adjusts.

Recently, our exposure to blue light has increased due to exposure to computer and TV screens, handheld devices, and energy-efficient light bulbs. Different colors of light are made up of different wavelengths, and the blue wavelength of light is more powerful at suppressing melatonin secretion than the other wavelengths. During the day this is positive and leads to improvements in attention, reaction times, and mood. In the evening, all wavelengths of light suppress the release of melatonin but blue light's more powerful melatonin suppression lasts twice as long as that from other wavelengths of light, leading to a further delay in the onset of sleep.

Blue light takes a greater toll on an already sleep-deprived population: teenagers. Many teenagers do not get enough sleep for their still-developing brains and bodies. Guidelines recommend 8-1/2 to 10 hours of sleep for older teenagers, but about 50 percent of them get less than seven. Part of the issue is that circadian rhythms shift to a later time in the teen years, but school still starts quite early in many districts. Some states have recognized this issue and have implemented later start times for middle and high schools.

The teenage population is also heavily into screen time, and research has found they are substantially more sensitive to the effects of blue light. A study at Harvard found equal melatonin suppression in teenagers as adults at only one tenth of the exposure to blue light. As they tend to be physically resilient and unaware of being tired, sleep deprivation in teenagers can be misdiagnosed as ADHD, depression or anxiety.

Some ways to decrease the effect of blue light and aid sleep - use red light for night lights which has the least effect on melatonin. Use coated bulbs that block some of the blue light. Turn screens off at least one hour (2 or 3 is better) before bed and turn the brightness setting down on screens. There are apps that can decrease the amount of blue emitted from screens and also blue-blocking glasses for those who need to work at night. Or let the house get dark as night falls and read an actual book for an old-fashioned approach.