An intriguing study from University College London suggests that the light we experience indoors may influence how our bodies process glucose — and that adding an invisible wavelength of near-infrared light could make a measurable difference.
Could the Light Around Us Be Affecting Our Metabolism?
We often think about nutrition, exercise and sleep when discussing metabolic health. But scientists are increasingly investigating another environmental factor: light.
For millions of years, humans evolved under natural sunlight, which contains a broad spectrum of wavelengths, including visible red light and invisible near-infrared radiation.
Today, many of us spend much of our working day under artificial LED lighting, which typically provides little near-infrared light.
Could that difference matter to our cells?
A research manuscript titled “Near-Infrared Light Regulates Human Glucose Levels in the Built Environment”, by Khorshid Meihami, Jemima Unwin Teji, Edward Barrett and Professor Glen Jeffery, investigated this question in real-world office conditions.
About Professor Glen Jeffery
Professor Glen Jeffery is a Professor of Neuroscience at UCL’s Institute of Ophthalmology. His research focuses on visual neuroscience, the retina and ageing, including how specific wavelengths of light may affect retinal cells and mitochondrial function. His work is one of the research areas we follow as we continue learning about red and near-infrared light.
The findings raise an intriguing possibility: the wavelengths missing from many modern indoor lights may have biological significance.
Understanding the Connection Between Light and Cellular Energy
At the centre of this research are the mitochondria.
Often described as the powerhouses of our cells, mitochondria help convert nutrients into ATP (adenosine triphosphate), the energy used to support essential cellular functions.
Glucose is one of the fuels our bodies use in this process.
Scientists studying photobiomodulation — the interaction of particular wavelengths of light with biological tissues — are investigating whether red and near-infrared light can influence mitochondrial activity.
The proposed relationship is that certain wavelengths may affect how efficiently cells use energy, potentially influencing glucose metabolism.
Although the precise mechanisms are still being investigated, the possibility that light could influence metabolic processes is attracting increasing scientific attention.
What Did the UCL Researchers Investigate?
The researchers recruited 24 healthy men, aged between 20 and 85, who worked in windowless offices.
Participants were randomly divided into two groups.
Group One: Standard LED Lighting
Twelve participants used an ordinary LED desk lamp without additional near-infrared illumination.
Group Two: LED Lighting Plus 850 nm Near-Infrared
The other twelve participants used a similar desk lamp supplemented with invisible 850 nm near-infrared light.
Both groups received approximately the same visible brightness, so the main experimental difference was the addition of near-infrared radiation.
The lamps were positioned near their computer workstations and used for two hours each morning over three consecutive days.
Researchers measured glucose regulation using oral glucose tolerance tests and continuous glucose monitors.
This allowed them to examine whether changing the spectrum of indoor lighting was associated with measurable changes in glucose levels.
What Did the Study Find?
In this small study, the researchers reported a statistically significant difference between the two lighting groups.
Participants receiving the additional 850 nm near-infrared light showed a reduction in glucose exposure during the oral glucose tolerance test, while the standard LED group showed an increase.
The study's main glucose-tolerance measure changed in opposite directions:
- Near-infrared group: a reduction in glucose exposure after the intervention.
- Standard LED group: an increase in glucose exposure after the intervention.
All 12 participants in the near-infrared group showed a reduction in the primary glucose-tolerance measure.
Continuous glucose monitoring also showed a similar overall direction of change, with average glucose levels falling in the near-infrared group and rising slightly in the control group.
These results suggest that the spectral composition of indoor lighting could influence short-term glucose regulation.
However, the study was small, lasted only three days, and included healthy men rather than people with diabetes. Larger and longer-term studies are needed to establish whether the findings translate into meaningful health benefits.
Why 850 nm Near-Infrared Light?
Near-infrared light is invisible to the human eye, but some wavelengths can penetrate biological tissue more deeply than visible light.
The researchers selected 850 nm, a wavelength frequently used in photobiomodulation research and equipment.
Unlike standard visible LED lighting, the experimental lamps included a measurable near-infrared component.
The study builds on earlier research investigating the effects of 670 nm red light on glucose regulation.
Together, these investigations suggest that different wavelengths of light may have different biological effects.
This does not mean that all LED lighting is harmful or that adding near-infrared light will automatically improve metabolic health.
It does, however, challenge the assumption that lighting only needs to be evaluated by how bright it appears to our eyes.
What Does This Mean for Our Homes and Workplaces?
Modern indoor lighting is generally designed around visibility, efficiency, colour and energy consumption.
Far less attention has traditionally been given to the possible metabolic effects of its wavelength composition.
Natural daylight contains a broader range of wavelengths than most conventional indoor LED bulbs.
The UCL research raises the possibility that future lighting designs could consider not only what humans need to see, but also how light interacts with human biology.
This could eventually influence the design of homes, offices and wellness environments.
For now, natural daylight remains an important part of a healthy daily routine, alongside appropriate lighting at night to support circadian rhythms.
Where Does Red and Near-Infrared Light Therapy Fit In?
At Oxygen Room, we follow developments in photobiomodulation research with particular interest.
Our red and near-infrared light technologies use selected wavelengths to provide controlled light exposure.
The 850 nm wavelength investigated in this study is also commonly used in near-infrared light therapy equipment.
However, there is an important distinction.
The researchers studied a particular desk-lighting arrangement, exposure duration and irradiance. Their results cannot automatically be applied to every red-light panel, lamp or full-body therapy system.
Photobiomodulation is being investigated across a range of applications, including cellular function, tissue recovery and physiological responses to light.
The relationship between near-infrared exposure and glucose metabolism is an emerging area of research rather than an established medical treatment.
A New Way of Thinking About Light
Perhaps the most fascinating aspect of this research is the idea that the quality of light in our everyday environments may matter beyond vision and sleep.
Our cells evolved in a world illuminated by the full spectrum of sunlight.
As our lifestyles become increasingly centred around artificial indoor environments, researchers are beginning to explore whether some of the wavelengths we have removed from those environments may have biological importance.
The findings are preliminary, but they open the door to further investigation into how light, mitochondria and metabolism interact.
At Oxygen Room, we believe the future of wellness lies in combining established healthy habits with a careful understanding of emerging science.
Light is more than illumination. It is an environmental signal that interacts with our biology — and we are still discovering how.
Scientific reference
Meihami, K., Teji, J. U., Barrett, E. & Jeffery, G.
Near-Infrared Light Regulates Human Glucose Levels in the Built Environment.
University College London research manuscript.
Related reading
Is Modern Lighting Disrupting Our Metabolism? The Science of Light, Health & Our Body Clock.
Explore our accompanying Oxygen Room guide discussing artificial light, circadian rhythms and metabolic health.
Discover Red & Near-Infrared Light Therapy at Oxygen Room
Explore our carefully selected range of red and near-infrared light products and learn more about the science of targeted light exposure.
This article is for educational purposes and discusses emerging scientific research. Near-infrared light therapy is not an established treatment for diabetes or other metabolic conditions and should not replace medical care, prescribed treatment, exercise or nutritional guidance.
