What We Lost When the Incandescent Light Bulb was Banned: Infrared Light Producing Relaxation and Pleasure
Blue-rich LEDs induce a stress response that makes us miss the calming effect of incandescent light
Traditional incandescent light bulbs were banned in 2023 because they did not meet the US Department of Energy (DOE) 45 lumens per watt standard for light bulbs. Only 12% of the electrical energy they consumed produced visible light, the other 88% created invisible infrared wavelengths. They have now been replaced by blue-rich LED light bulbs which produce a narrow spectrum of visible light with no infrared.
This ban on incandescent light bulbs would seem to make sense if you believe the only function of a light bulb is to banish darkness and aid vision. However, we are now learning increasingly more about the critical health-promoting properties of infrared light on mitochondrial health, metabolism and healing. That will be the subject of a later Substack article. But today we will focus on the prevention of stress.
Infrared Light Produces Relaxation and Pleasure
A new study shows that invisible near-infrared light also calms down the sympathetic fight-or-flight response and induces a state of relaxation and pleasure.
Lights that emit near-infrared in the 800-1000 nm range were shown to increase heart rate variability, a marker of parasympathetic activity. This is part of our body’s autonomic control system which can either activate us in times of danger or challenge (sympathetic nervous system). or calm us down when we are safe and can relax. (parasympathetic nervous system). This autonomic nervous activity can be tracked objectively using an EKG because the sympathetic system makes the heart beat faster, but also more regularly, whereas the heart rate slows under the parasympathetic influence but also becomes slightly more irregular (i.e. the beat-to-beat interval is more variable).
To avoid any placebo effects the study used a simple cubicle with white overhead lights. The study volunteers could not tell whether or not a white LED light fixture was emitting near-infrared light in addition to the visible light, or whether they were just getting the white blue-rich LED light without any added infrared.
The research team, as reported by Roddick et al, in the Journal of Environmental Psychology1, showed the study volunteers had a significant decrease in heart rate variability, and an increased subjective sense of pleasure when the lights contained infrared wavelengths.
Blue-Rich LED lights produce a stress response
In contrast, the LED lights we are forced to use to meet the ever more stringent DOE energy standards are rich in blue, green, and yellow but deliver no ultraviolet or infrared. They are, therefore, missing many of the ingredients of natural outdoor light, which is rich in ultraviolet, all the visible colors of the light spectrum, and lots of infrared light.
The blue content of high CCT LEDs induces stress, and an alerting response. Heart rate variability, a measure of sympathetic nervous system activity, is increased by bright blue-rich light, and if blue-rich lights are used in the evening prior to bedtime, they generate a lingering unhelpful sympathetic nervous stress response that continues even during sleep2.
So, what we are missing in our homes today is the calming influence of infrared-rich incandescent light. The incandescent light bulbs we used to have in our homes in the evening aided the transition to restful sleep.
Even though you cannot buy incandescent light bulbs because of the DOE energy regulations, there is a solution. Silas Technologies offers NIRA light bulbs that emit infrared as well as visible light. These can meet the current 45 lumens per watt energy regulations, but even this solution will go away in 2028 when the 125 lumens per watt minimum requirement for light bulbs comes into effect.
We are now more fully appreciating what we are missing by progressively banning light bulbs that provide healthy spectral content. I urge you to join the campaign to protect healthy lighting and indicate that you are willing to sign a petition to reverse the harmful DOE 125 lumens per watt rule which is scheduled to go into effect in 2028.
For more remarkable insights into what we have done to ourselves by moving indoors and switching on narrow spectrum blue-rich LED lights, see my book THE LIGHT DOCTOR.
Roddick CM et al. (2024) Effects of near-infrared radiation in ambient lighting on cognitive performance, emotion, and heart rate variability Journal of Environmental Psychology 100: 102484
Ishibashi K et al (2007) Inhibition of Heart Rate Variability during Sleep in Humans by 6700 K Pre-sleep Light Exposure J Physiol Anthropol 26(1): 39–43, 2007 http:/www.jstage.jst.go.jp/browse/jpa2 [DOI: 10.2114/jpa2.26.39]
The term "energy efficiency" is a myth, and we recently interviewed Mark Baker of the Soft Lights Foundation, who is suing the FDA on safety limits surrounding LEDs and the myth of efficiency:
https://romanshapoval.substack.com/p/led
I do miss the incandescent lights