Blue light is a lot more terrible than we think. If affects your physiology in such a manner that it may cause terminal illnesses. Harvard Health Publishing from Harvard Medical School recently shared a letter about blue light’s dark side. I have posted the main points in this blog post.
Exposure to blue light at night, emitted by electronics and energy-efficient lightbulbs, harmful to your health.
At night, light throws the body’s biological clock-the circadian rhythm-out of whack. Sleep suffers. Worse, research shows that it may contribute to the causation of cancer, diabetes, heart disease, and obesity.
Blue wavelengths-which are beneficial during daylight hours because they boost attention, reaction times, and mood-seem to be the most disruptive at night. And the proliferation of electronics with screens, as well as energy-efficient lighting, is increasing our exposure to blue wavelengths, especially after sundown.
Dr. Charles Zeisler of Harvard Medical School showed, in 1981, that daylight keeps a person’s internal clock aligned with the environment.
Nighttime Light Health Risks
Study after study has linked working the night shift and exposure to light at night to several types of cancer (breast, prostate), diabetes, heart disease, and obesity. It’s not exactly clear why nighttime light exposure seems to be so bad for us. But we do know that exposure to light suppresses the secretion of melatonin, a hormone that influences circadian rhythms, and there’s some experimental evidence (it’s very preliminary) that lower melatonin levels might explain the association with cancer.
Every dim light can interfere with a person’s circadian rhythm and melatonin secretion. A mere eight lux-a level of brightness exceeded by the most table lamps and about twice that of a night light-has an effect, notes Stephen Lockley, a Harvard sleep researcher. Light at night is part of the reason so many people don’t get enough sleep, says Lockley, and researchers have linked short sleep to increased risk for depression, as well as diabetes and cardiovascular problems.
While light of any kind can suppress the secretion of melatonin, blue light at night does so more powerfully.
Richard Hansler, a light researcher at John Carooll University in Cleveland, notes that ordinary incandescent lights also produce some blue light, although less than most flourescent lightbulbs.
Remedies
Use dim red lights for night lights. Red light has the least power to shift ciradian rhythm and suppress melatonin.
Avoid looking at bright screens beginning two to three hours before bed.
If you work a night shift or use a lot of electronic devices at night, consider wearing blue-blocking glasses or installing an app that filters the blue/green wavelength at night.
Expose yourself to lots of bright light during the day, which will boost your ability to sleep at night, as well as your mood and alertness during daylight.
Stay tuned to our blog for more great content like this one!
