The Impact of Blue Light on Chronic Diseases

by Paul Shepherd
| September 10, 2020
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For the past 130 years, artificial light has gone up every decade. Because of the increase of human-made light sources, people are exposed to more blue and green light than ever before.

This type of light regulates your sleep-wake cycle and many other vital processes in your body. That’s why artificial light at night is responsible for poor sleep, increased cancer rates, and the growing burden of obesity, diabetes, heart disease, dementia, and other chronic diseases.

In this article, you’ll learn the scientific definition of blue light, how it affects your body on a cellular level, the consequences of long-term blue light exposure, and bright ideas for preventing blue light toxicity for yourself and your family.
What is Blue Light?

Blue light occurs in the natural visible light spectrum of sunlight but is also emitted by human-made light bulbs, energy-efficient lighting devices, and digital devices like televisions, computers, tablets, and mobile phones.

The wavelength of blue light is approximately 380-550 nanometers. It is one of the shortest, highest-energy frequencies.

Your body responds differently to various portions of the light spectrum. Blue light in your environment is responsible for regulating your circadian rhythms, which affect your sleep-wake cycle and the function of over half of the genes in your body[*].

Artificial light, which contains more blue light than the natural spectrum, lowers your body’s production of melatonin (the “sleep hormone”) at night and disrupts your natural, healthy body rhythms.

Because melatonin helps you get to sleep and allows your cells to repair themselves overnight, reduced melatonin production damages your mitochondria and enables mutations to occur in your DNA[*][*].

What are Mitochondria?

Your mitochondria, commonly called “the powerhouses of the cell,” are tiny structures contained in your cellular membranes. They produce the energy your body needs to function.

You can think of mitochondria as the “batteries” that power your cellular “hardware.” Light in your environment acts as an “operating system” that directs your mitochondria and cells, and also provides them with energy in the form of photons.

If you’ve ever tried to use an old device with poorly functioning batteries and a buggy operating system, it’s easy to understand why mitochondria and light are essential for health and wellness.

When you overcharge a battery, use the wrong power source, or allow it to become damaged, the associated hardware usually malfunctions because it isn’t receiving the necessary power to work correctly.

Dysfunctional mitochondria prevent your cells from carrying out their duties, which causes damage and illness in your body.

Because your body relies on energy production and signaling from your mitochondria, this process leads to symptoms like daytime sleepiness, fatigue, mood problems, mental health issues, headaches, and poor vision[*][*][*][*][*].

Mitochondrial issues are also the source of many modern chronic diseases.

Consequences of Long-term Blue Light Exposure

It may seem surprising or even shocking that everyday exposure to artificial light sources is behind the rise in chronic disease, but by understanding this important fact, you can empower yourself to live a longer, healthier life.

Long-term blue light exposure has a cumulative effect, creating more mitochondrial dysfunction over time. If you expose your eyes and skin to artificial light at night repeatedly, your brain’s circadian clock and your pineal gland, which makes melatonin, can also be severely damaged[*][*].

Low melatonin levels are associated in research with higher rates of cancer[*]. Another way that blue light and mitochondrial dysfunction cause cancer is by increasing the number of DNA transcription errors[*][*]. The International Agency for Research on Cancer considers circadian disruption caused by artificial light a “probable carcinogen to humans”[*].

Many epidemiological studies have found that artificial light at night also leads to diabetes, heart disease, obesity, and macular degeneration[*].

“Normal” exposure to artificial blue light and the mitochondrial damage it causes may be responsible for many seemingly unrelated medical conditions, including schizophrenia, bipolar disorder, Alzheimer’s disease, dementia, epilepsy, strokes, neuropathic pain, Parkinson’s disease, diabetes, and hepatitis C[*].

Top 3 Ways to Prevent Blue Light Toxicity

In light of the concerning research on blue light toxicity, more people are taking steps to prevent blue light toxicity to enhance their health, wellness, and physical and mental performance. Here are three easy ways you can mitigate the harmful effects of artificial light at night.

#1: Be Wise During Screen-time

Although it may be tempting to check emails and social media right before bedtime, research shows that using screens before bed is detrimental to your sleep, health, and well-being[*][*][*][*].

Here’s how you can be wise about screen-time:

  • Don’t use digital devices for 2-3 hours before bed.
  • Don’t use digital devices in a dark room.
  • Consider using blue light filtering apps for your computers, phones, and tablets.

Apps like Iris, F.lux, Twilight, and Night Shift reduce the amount of blue light emitted by your device’s screen, but they’re not a perfect solution. It’s a great start, but for optimal sleep and mitochondrial health, a blue light filtering app isn’t sufficient by itself.

#2: Wear Blue-Blocking Glasses

As people wake up to the detrimental effects of artificial light at night, the popularity of blue-blocking glasses is on the rise.

Studies show that wearing these specialized blue blockers at night allows you to maintain an earlier bedtime, achieve deeper sleep, and be more awake during the day[*][*][*]. They also prevent damage to your retina that can lead to macular degeneration and early vision loss[*][*][*].

Balancing your light exposure can improve your mood, cognition, and performance at work.

Unlike blue light filtering apps, quality blue blockers block 100% of the high-energy wavelengths that disrupt your sleep and damage your mitochondria. Another advantage of blue-blocking glasses is that they also filter harmful light sources like LED and fluorescent lights.

Mito Shades feature lightweight frames and high-impact, pigment-blended lenses. They block 100% of blue and green light, which improves your sleep and preserves your natural body rhythms.

Wearing Mito Shades at night improves your sleep and reduces your risk of insulin resistance, diabetes, high blood pressure, heart disease, cancer, and other chronic diseases[*][*][*][*].

#3: Create a Healthy Home Environment

In addition to using filtering apps and wearing blue-blocking glasses after dark, here are some easy, inexpensive ways to improve your home environment for better rest and repair at night:

  • Install heavy blackout curtains in your bedroom to block street lights and car headlights
  • Keep a red LED flashlight or headlamp by your bed for nighttime bathroom visits (unlike blue light, dim red light has minimal impact on your sleep-wake cycle[*])
  • Replace “energy-efficient” LED and fluorescent bulbs with incandescent or warm-temperature bulbs

The spectrum of clear or soft white incandescent bulbs is closer to the natural range, with less blue light compared to LEDs and fluorescents. They are suitable for daytime use and have less of an adverse effect on your circadian rhythms.

If you genuinely want to create an ideal environment in your home, you can also install yellow- and red-tinted incandescent bulbs to further reduce blue light after dark.

Edison-style incandescent bulbs are another excellent low-blue-light option, but be sure to avoid “LEDisons” (LED bulbs designed to resemble incandescent Edison bulbs).

The Bottom Line

Light pollution and artificial light exposure have reached unprecedented rates, and continue to grow annually. As a result, the frequency of chronic diseases associated with sleep issues and mitochondrial dysfunction is also on the rise.

The good news is that you can immediately enhance your health, sleep quality, and overall performance by preventing blue light toxicity.

If you get wise about screen-time, wear blue-blocking glasses at night, and make a few changes around your house, you can look forward to improved well-being and a reduced risk of diseases like high blood pressure, heart disease, cancer, diabetes, dementia, and vision loss.

Image credits: Close up of smartphone in hand by Japanexperterna CC BY-SA 2.0.