You may have heard you should limit your exposure to light at night to avoid disrupting your sleep. But did you know that exposure to blue light and energy-efficient light bulbs can be particularly bad for your health? An article published in Harvard Health Publications points out some big concerns when it comes to soaking up too much of these blue wavelengths, especially toward the end of the day.
What is Blue Light?
Blue light has a short wavelength, second only to violet and can be found in most energy-efficient light bulbs and electronic devices.
Circadian Rhythms and Artificial Light
Not too long ago, when night fell, we were all left in the dark. In fact, before the advent of artificial light, we typically followed the patterns of the sun and moon for our waking and sleeping hours. This directly coordinates with our circadian rhythms—which are the physical, mental and behavior changes that happen during a 24-hour period. These responses are dictated primarily by light and dark and are found in most living things.
The invention of light changed our world—and most would agree they couldn’t live without it, but it hasn’t come without drawbacks. Research shows that using lights at night can throw off your natural circadian rhythm and disrupt your sleep patterns. Not only that, but it can also influence other more serious health issues.
Known and Potential Health Risks
While researchers aren’t exactly clear on why nighttime light negatively affects our health, there are many studies that link high rates of breast cancer, prostate cancer, heart disease and obesity to those who work the night shift. One study performed by Harvard found that the gradual shift of the participant’s circadian rhythms caused an increase in blood sugar levels. This surge put them into a prediabetic state and also decreased the levels of lepin in the body, which is the hormone that tells you you’re full after a meal.
Melatonin Secretion and Blue Light
We know that any light can affect melatonin secretion, which helps to regulate your sleep-wake cycle, with peak levels naturally occurring at night. And, for an unknown reason, blue light has a much stronger effect on disrupting your melatonin secretion. Another study showed that blue light suppressed melatonin for twice as long as green light—changing circadian rhythms by twice as much.
Blocking-out the Blues
Unfortunately, it’s impossible to avoid blue light (or nighttime light) altogether, but there are a few things you can do to limit your exposure:
- Purchase blue light-blocking glasses
- Use red lights for nighttime
- Put away your electronics two to three hours before bed
- Get healthy amounts of natural light during the day