According to University College London neuroscientist Professor Glen Jeffery and former European Space Agency and Hubble scientist Dr. Bob Fosbury, modern LED lighting has created what they warn is a "clear and present public health emergency" by leaving people living in "infrared darkness." In an exclusive for The European, the researchers warn that modern LED lighting has left us living in what they call “infrared darkness” – deprived of wavelengths that help our mitochondria function properly.
Did you know? Before LEDs were introduced, lighting used to account for around 20 per cent of global electricity consumption. Now it stands at around 8 per cent, with LEDs ushered in with a compelling promise to reduce the energy needed to create artificial light by up to 90 per cent.
The Hidden Spectral Deficit of Modern LED Lighting
Traditional artificial light sources, such as candles, oil lamps, incandescent bulbs and halogen lamps, also emit longer wavelengths. Sunlight contains the full visible spectrum and extends into infrared.
Not for nothing, then, did the 2014 Nobel Prize in Physics recognise the invention of efficient blue light-emitting diodes, which made bright, energy-saving white light possible. However, conventional LEDs provide little or no infrared light to balance the short wavelength blue, emitting a high proportion of short-wavelength blue light, with some of this falling between 420 and 450 nanometres (nm).
According to Professor Jeffery, who is Professor of Neuroscience at UCL’s Institute of Ophthalmology, this missing spectral range carries biological consequences. "We found that neuronal damage was considerably slowed by being exposed to red light," Jeffery told The European, describing how his investigations into vision recovery led him to study mitochondrial function. He goes so far as to call conventional LED lighting the “new asbestos.”
How Short-Wavelength Blue Light Impacts Cellular Mitochondria
Mitochondria are structures within our cells that help convert energy from food into ATP, a molecular fuel used by the rest of the cell. Jeffery’s laboratory experiments on animal models indicate that specific light wavelengths exert vastly different pressures on these cellular structures.
"We watched the mitochondria directly in the animal model and we found clearly that red light to near infrared light was having a very positive effect. And we found that short wavelengths, like deep blues, were having a very negative effect," Jeffery explained.
- The Battery Analogy: Jeffery uses a battery analogy to explain the proposed mechanism, noting that the blue light discharges the battery.
- Animal Model Findings: Mice exposed to ordinary LED lights display mitochondrial distress, unable to use as much glucose as normal. They tend to be less energetic, to put on weight and to develop fatty liver disease.
- Blood Signalling: Experiments demonstrate that it changes the blood signalling through what are called cytokine profiles.
- Cellular Stress: Other experiments in fruit flies found that daily 15-minute exposures for a week significantly reduced mitochondrial complex activity and increased membrane permeability, while a single three-hour exposure significantly reduced ATP levels and mobility.
Furthermore, Jeffery added that blue light is strongly absorbed by chemicals called porphyrins which can result in inflammatory responses.
Photometabolism and the Evolutionary Need for Infrared Light
Dr Bob Fosbury worked for 26 years at the European Space Agency as part of its collaboration with NASA on the Hubble Space Telescope. As Astronomer Emeritus at the European Southern Observatory and an Honorary Professor at the Institute of Ophthalmology, UCL, Fosbury argues that human biology evolved under the full spectrum of sunlight.
"Life on earth is an antenna tuned to sunlight," Fosbury explained. He highlights a process termed photometabolism, explaining that it needs components of sunlight to metabolise properly over four billion years of evolution.
Fosbury warns that people indoors are in infrared darkness. The concern, they argue, is not blue light in isolation but the absence of infrared light from LED-dominated environments in which we as people spend so much time. He compares this part of the spectrum to a servicing centre that keeps the mitochondrial engine running smoothly. The disease develops on the same kind of time scale as scurvy, when ancient sailors gradually suffered from a lack of Vitamin C.
Pro Tip: To reintroduce missing infrared wavelengths into an indoor space, Professor Jeffery suggests introducing an incandescent or halogen bulb into an LED-lit room to make sure that fuller-spectrum light is present.
Practical Solutions and Restoring Natural Light Exposure
Because traditional incandescent bulbs have largely disappeared from consumer markets, while most halogen bulbs have also been phased out in the UK as lighting standards have shifted towards more energy-efficient LEDs, researchers point to alternative remedies for chronic light deficiency:
- Outdoor Exposure: Jeffery stresses the importance of getting outside, especially in the morning and evening, while avoiding excessive ultraviolet exposure, as natural daylight contains the red and near-infrared wavelengths largely missing from conventional LED lighting.
- Environmental Design: Fosbury adds that tree leaves reflect infrared light, and states their hypothesis that forests act not only as producers of food through photosynthesis but also as rich natural sources of biologically active near-infrared light for the wider ecosystem.
- Lighting Technology: His lab is also experimenting with introducing elements at 850 nm into LED lamp clusters, a design change intended to provide some of the longer wavelength light missing from conventional LEDs.
Warning: While researchers advocate for increased access to fuller-spectrum lighting and natural daylight, they stress the importance of avoiding excessive ultraviolet exposure.
Frequently Asked Questions
Is all blue light harmful to human health?
According to Professor Glen Jeffery, what he calls the “nasty blue” short wavelength light between 420 and 450 nm can impair mitochondrial function, and the rest of the blue light is not a problem.
Why do LEDs lack infrared light?
Because conventional LEDs strip out much of this longer-wavelength light, unlike traditional sources of artificial light, such as candles, oil lamps, incandescent bulbs and halogen lamps, which also emit longer wavelengths.
Can red and near-infrared light penetrate clothing?
Yes. Jeffery’s research has shown that long wavelength red and near-infrared light can penetrate deeply into the human body, including through clothing.
What practical steps can individuals take indoors?
Researchers suggest introducing an incandescent or halogen bulb into an LED-lit room to make sure that fuller-spectrum light is present, alongside getting outside, especially in the morning and evening.
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