You may have heard mention of blue light in news reports, conversations at work, or in any of your favorite health centered social media feeds. Most of the time talk of blue light centers on how dangerous and destructive to your health it is.
I have found that despite slowly becoming a popular health buzzword most people aren't exactly sure what blue light is or how it impacts your health.
Blue light is now a mainstay in modern life and its effects are robust so let's explore exactly what blue light is, how you can optimize its benefits in your life and most importantly what steps you can take to mitigate blue lights deleterious effects on your sleep and health.
To understand how blue light impacts your health, we need to first take a step back and talk about circadian rhythms and their impact on how your body functions.
Everyone's body (not just the human body but also animals, plants, and even bacteria) runs on what is called the circadian rhythm. This is a ~24-hour cycle that corresponds with the light dark cycle of their world.
For humans sensing sunlight in the morning sets off a cascade of biological events that impact foundational processes in our body. As darkness approaches, your body responds by starting, stopping, and adjusting more biological processes. As you can imagine light from the sun is a (THE?) powerful regulator of these changes.
The light/dark cycles that drive circadian rhythms are extremely important for the regulation of sleep. Your body's master clock is a group of cells in your brain called the suprachiasmatic nucleus (SCN). The SCN is located in very close proximity to the major nerves of your eyes (your optic nerves). This allows the light that your eyes take in to be readily analyzed and assessed by your SCN so that the SCN can properly direct different bodily functions depending on the time of day. (How incredible is the human body?!)
Humans invented light bulbs to help get around the limits light/dark cycles of the sun so that we could work and live more on our own terms. This use of artificial light has biological consequences that are further enhanced depending on the kinds of lights that you are using.
Back in 1958 researchers Woodland Hastings and Beatrice M. Sweeney began testing how different colors of light could modify the circadian rhythms of microscopic dinoflagellate organisms. What these two innovative scientists discovered in photosynthetic marine microbes was also extremely relevant to humans.
They found that of all the different color lights, blue light was the most effective and efficient at adjusting and even reseting circadian rhythms in dinoflagellates (as we now know it does this with humans too). Sweeney and Hastings were ahead of their time as their work, despite being published, went unnoticed for years.
What does it mean to adjust or reset your circadian rhythm? Image this...you wake up in the AM and your body sees the bright morning sun, your 24-hour body clock is intune with its normal circadian rhythm. Your day progresses and then as the latter part of your body's 24 hour cycle begins to kick into gear (inline with the sun settings) - you are exposed to concentrated blue light. Your eyes soak up this light making your body think that it is not time to begin winding down but instead that it is early again, back at the beginning of your 24-hour cycle. Your body literally doesn't know what is going on.
You may be thinking...
"Humans have been using artificial light for decades upon decades why is this just now an issue?"
Totally valid thought.
In fact the first patent for an incandescent light bulb was awarded in the 1840s.
The reason that blue light is becoming such an issue now has to do no just with improvements in scientific research and understanding of human biology but also the evolution of the lights that we are using. The traditional incandescent light bulb emits low levels of blue light. Newer, energy efficient, LED and florescent lights are blue light powerhouses! LED lights are require less energy to run, run longer, and can sometimes even be cheaper (although most energy efficient bulbs are still more expensive as your local hardware store). These value add-ons to LED lights over traditional incandescent lights have made them very popular.
But when it comes to your health - a traditional incandescent light is probably better since they emit significantly less blue light. Energy efficient lights aren't the only place where you are exposed to blue light. In fact they probably aren't the major offender in your life.
How often do you stare directly at the light bulb in your living room with your nose 6 inches from the light for 30 minutes straight?
Probably not that often :)
But when was the last time you used a phone, tablet, or computer for 30 minutes straight?
Screen based technology is far an away the biggest contributor to blue light intoxication in our lives.
The biggest and most prominent negative effect has to do with sleep. Blue light exposure is linked poor sleep quality and inability to fall sleep. Blue light acts on the SCN (remember your body's master clock of neurons we talked about earlier) and blocks it from releasing a hormone called melatonin. Melatonin is an important hormone for initiating the normal sleep process. Bad sleep and/or insufficient sleep has a lot of negative downstream effects on your health.
Yes. Exposure to blue light has been shows to improve mood, reaction time, and attention. In modern society we don't have any issues with getting enough blue light to gain these benefits. Blue light during the day, especially in the morning is a good thing! Our biggest challenge is controlling blue light at inopportune times to attenuate their negative effects on circadian rhythm.
Here is a list of practical things that you can do to control blue light exposure so that you can sleep better and support more robust circadian rhythm for your body.
Expose yourself to sun light (or artificial blue light) as soon as you can upon waking to sync your circadian rhythm with your morning.
Minimize the use of bright phones, computers, tablets, and LED TVs close to bed. Ideally you curtail your exposure to these things 2-3 hours before bedtime. If you can't do 2-3 hours - do the best your can.
Use Apps to Reduce Blue Light From Being Emitted from phones, computers, and tablets. Programs and apps like Fl.ux, Night Shift (iOS or MacOS), and Twilight (Android) work to have your device emit less blue light based on when the sun rises and sets where you live helping keep you inline with your natural circadian rhythm. We still don't know the exact effectiveness of these programs/apps but they should be something that everyone who uses a phone, tablet, and/or computer have installed and activated (Night Shift comes preinstalled in iOS or MacOS devices).
Use dim red light as night lights or reading lights. Red lights have very minimal impact melatonin release. There are a variety of companies that sell 'sleep friendly' reading lights and night lights. These are great for kids as children are also susceptible (potentially more) to circadian rhythm perturbations due to blue light.
Wear blue blocker glasses. This is for the uber committed, but research shows that blue light blocking glasses can essentially eliminate the negative effects of blue light on your brain and body. Walking around at night with funny looking glasses is a deal breaker for many people but if sleep is a big issues I wouldn't discount their effects.
Take Cerevan. Cerevan contains FloraGLO. FloraGLO is a patented form of the antioxidant lutein. When you take Cerevan, FloraGLO is concentrated in your eyes where it has been shown in numerous research studies to filter out blue light. This reduces the amount of blue light that reaches your SCN (and thus reducing the level that blue light can disrupt your circadian rhythm). While Cerevan was formulated to improve memory and attention it has the added side effect of helping to safeguard your eyes from blue light exposure often associated with LED screens.
Excessive or inappropriate blue light exposure isn't going away anytime soon. It is part of modern life. You can't avoid it entirely but you can take steps to minimize it later in the day and especially before bed. You'll sleep better and you'll be healthier for it!