Updated: Apr 28
After reading the work of Drs. Jack Kruse, Bill Lagakos, and Alexander Wunsch, I am persuaded that blue light should be of grave concern for those interested in optimal health. Please read on for a brief explanation.
Mother Nature's Lighting
Sunlight emits a particular array of light frequencies (colors) that change throughout the day. Whatever you believe about evolution, the sun and its signature light patterns have been around since the beginning. Our bodies are tuned to its particular light frequency output, and the overall cycle of light/dark found in nature. Each color in sunlight can be thought of as a wireless signal that our bodies respond to upon contact at our eyes or skin. This includes the invisible, quantum wavelengths of ultraviolet and infrared. As you can see in the graph below, sunlight is balanced by all the colors of the rainbow, and so individual signals or colors blend together to form still more complex signaling, augmenting or balancing out the message. If some of the individual signals were isolated, for example blue frequencies, the response in our bodies would be excessive wakefulness and alertness. However, in sunlight, Blue light is never seen without red light, and other colors. In fact, red light (and infrared light) is the same 42% of sunlight from the time the sun is up to the time it sets, at any latitude in the world, year-round. This is in contrast to ultraviolet frequencies, which only appear for a portion of daylight hours, depending upon latitude and time of year.
Paying attention to the sun's behavior can help us optimally align our behaviors and light diet for optimal health.
The graph below compares light output of natural sunlight vs. manmade sources.
In stark contrast to sunlight, with manmade light, blue light is uncoupled from red light. The other light sources in the graphic above are all manmade. These have only been around for about 120 years, with CFL and LED much less. You can see how they compare in proportion of different wavelengths and irradiance (strength) to the sun. They are equivalent to an alien sun! Specifically, LED and fluorescent (CFL) have very large spikes in blue without much red to speak of. The incandescent bulb is akin to being the best of the worst, in that it does have some healthy red and not much blue, but certainly misses the mark for matching full sunlight.
Another problem with manmade light is that is imperceptibly flickers, a result of our AC power system, as well as energy saving circuitry of LED and CFL bulbs. This has been shown to negatively effect us at a cellular level (Bucha effect). Sunlight has ZERO flicker.
Adding to the problem, modern glass filters out certain frequencies of the sun, further contributing to an alien spectrum when indoors.
Unfortunately, all of our Screens have the same inherent frequency imbalance as well. Laptops, phones, TVs, tablets, even the display screens in your car or on your printer all emit excessive, unbalanced levels of blue light.
Now think about how much time you spend under an alien sun, indoors behind glass and under manmade lighting.
Ill Effects of Blue Light
So what has scientific research shown about the effects of manmade lighting? See below for a small sampling of the available Literature.
Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans
"These findings indicate that room light exerts a profound suppressive effect on melatonin levels and shortens the body's internal representation of night duration. Hence, chronically exposing oneself to electrical lighting in the late evening disrupts melatonin signaling and could therefore potentially impact sleep, thermoregulation, blood pressure, and glucose homeostasis."
Light Exposure at Night Disrupts Host/Cancer Circadian Regulatory Dynamics: Impact on … Tumor Growth Prevention
“The central circadian clock within the suprachiasmatic nucleus (SCN) [located in between our eyes and brain] plays an important role in temporally [time-based] organizing and coordinating many of the processes governing cancer cell proliferation and tumor growth in synchrony with the daily light/dark cycle.”
Cancer metastasis: Mechanisms of inhibition by melatonin
"Mounting evidence indicates that melatonin, employing multiple and interrelated mechanisms, exhibits a variety of oncostatic properties in a myriad of tumors during different stages of their progression."
Study links fluorescent lighting to inflammation and immune response
“The study showed genome-wide changes of gene expression patterns in skin, brain and liver for two commonly utilized experimental models (zebrafish and mice), following exposure to 4,100 K ‘cool-white’ fluorescent light,” Walter said. “In spite of the extreme divergence of these animals (i.e., estimated divergence of mice and fish about 450 million years), and drastically different lifestyles (i.e., diurnal fish and nocturnal mice), the same highly conserved primary genetic response that involves activation of inflammation and immune pathways as part of an overall acute phase response was observed in the skin, brain and liver of all three animals.”
Sleeping with artificial light at night associated with weight gain in women
"Humans are genetically adapted to a natural environment consisting of sunlight during the day and darkness at night," Jackson said. "Exposure to artificial light at night may alter hormones and other biological processes in ways that raise the risk of health conditions like obesity."
Blue light has a dark side - Harvard Medical School
"While light of any kind can suppress the secretion of melatonin, blue light at night does so more powerfully."
There is a growing body of scientific literature echoing and expanding upon the above. Blue light, as well as breaking the circadian cycle of day/night with light emitting technologies has negative biological consequences.
Please review our other blog on practical tips for establishing a better light diet in your life. And remember the key to all of this...
You can't replace the sun!