Blue Light Exposure and Sleep Effects – What Does Scientific Research Say?
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Did you know that poor sleep is linked to obesity, depression/anxiety, type 2 diabetes, and heart disease? While such health risks are already a huge concern, an article appearing in the Journal of Environmental Health Perspectives suggests that the electronics and artificial light we use to extend our days may be potent culprits to our sleep problems. The obvious question that follows—and one that I’m sure you’re asking—is, “what is the connection between blue light and sleep problems?”
Read on for a scientific take on the sleep effects of blue light exposure.
Here’s How Blue Light Disrupts Your Much-Needed Sleep
Ever heard of the circadian rhythm—aka. your 24-hour wake-sleep cycle controlled by an internal clock in your system? This rhythm basically determines when your body should get some shut-eye and when you should get to grinding in the morning. External stimuli (i.e., darkness and daylight) from the environment stimulate receptors in your eyes to influence the circadian rhythm.
Drawing on the findings of several studies, the effects of blue light on sleep patterns and quality of sleep are twofold. On the one hand, I found a bunch of studies suggesting that the right exposure to blue light could help improve your performance and mood. On the darker side of the narrative, blue light also appears to be a major culprit to your diminishing quality and quantity of sleep.
Narrative A: Studies Showing that Blue Light is Beneficial
- According to a study published in the Journal of Behavioral Neuroscience, the blue light emitted by the sun helps improve mood, subjective sleepiness, and performance.
- A UK study appearing in the Scandinavian Journal of Work, Environment, and Health concluded that “Exposure to blue-enriched white light during daytime work hours improves subjective alertness, performance, and evening fatigue/sleepiness.” This shows that blue light may be an effective way to improve productivity at the workplace.
- In a 2004 study by researchers affiliated to the University of Helsinki, the finding showed that blue light could have therapeutic applications. Specifically, they found out that blue light therapy had “promising antidepressant efficacy” and as an “adjunctive treatment to sleep deprivation.”
Narrative B: Studies Linking Blue Light to Your Sleep Problems
- Quoting an informative study published in The Journal of Clinical Endocrinology & Metabolism, “chronically exposing oneself to electrical lighting in the late evening disrupts melatonin signalling and could therefore potentially impact sleep, thermoregulation, blood pressure, and glucose homeostasis.” This draws attention to the artificial room light—especially LEDs—that we tend to bathe in before bedtime.
- Although both green light and blue light are known to suppress melatonin, the latter appears to have a more profound effect. Based on information from an article in the Harvard Health Letter, blue light has been shown to suppress melatonin and shifted circadian rhythms 2x more than green light. The article went on to recommend using dim light or making use of blue light filters.
- I found dozens of studies linking the melatonin suppression associated with blue light to various health problems. One such study showed that the level of melatonin plays a crucial role in cardiovascular physiology—including blood pressure and heart rate. In another article in the Annals of Medicine, the researchers associated melatonin suppression and sleep deprivation to an increased risk of obesity.
Long story short, the message in these studies is that blue time is beneficial during the daytime as nature intended. The problem arises when we’re exposed to artificial blue light into the night. This tricks our internal clocks into thinking it’s daytime—hence inhibiting the effective production of melatonin, which negatively affects our quality and quantity of sleep.
How Can You Improve Your Sleep Amid This Blue Light Fiasco?
Minimizing the negative effects of blue light comes down to preventing our exposure to it. This may mean winding down and ditching all blue light-emitting devices before bedtime and dimming lights. But if that is too radical for you, consider grabbing a pair of blue-light-blocking glasses.
In a 2-week study by the University of Toledo, the research compared the sleep patterns of two groups of respondents—one with blue-light-blocking glasses and another without. The findings showed that the group with blue light glasses experienced notable improvements in their mood and sleep quality. However, it’s important to note that some studies point to a lack of quality evidence supporting the benefits of these glasses on sleep quality.