An interesting change happened within the built environment over the past few decades. Along with major changes in our food environment and movement patterns our light environment completely changed. Perhaps this may be a part of the puzzle in what has caused the increase in chronic illnesses over the past few decades? There will be multiple factors but the current research particularly on red and near infrared light is fascinating and certainly worth following to see where it goes.
What do I mean by our light environment changed? Well gradually we removed full spectrum light from our indoor environment and our lives overall limiting it to predominantly blue light. A combination of factors caused this, firstly our move to life mainly indoors and secondly a desire to make lighting more energy efficient.
Due to the energy saving potential incandescent light bulbs were gradually replaced by LED bulbs which only use the visible spectrum. In other words wavelengths of light that we can actually see. However there are numerous wavelengths of light radiating from the sun, many of which even if we cannot see them interact with the body. Two of the spectrums we lost from our indoor lighting are red and near infrared (NIR)

Add to this double glazing and glass that filters out UV light and less time spent outside and we might all be suffering a light deficiency.
This is a reasonably recent issue, in the past we were exposed to full spectrum light from sunlight, firelight, candles, oil lamps and incandescent bulbs. Essentially if a light source produces light and heat it likely will also be producing near infrared and red light also. Near infrared and red light can now also be found in light panels created deliberately to emit these frequencies. In the past decade photobiomodulation has become an expanding area of research with researchers from diverse backgrounds including medics, engineers and NASA scientists all looking at different areas. Discoveries so far include:-
1. **Wound Healing and Tissue Repair**:
NIR light has been shown to accelerate wound healing and tissue repair. Research indicates that it can stimulate cellular regeneration and reduce inflammation, which aids in faster recovery.[1]
2. **Pain Reduction**:
Studies suggest that NIR light can alleviate pain by reducing inflammation and promoting blood flow to the affected areas. It is particularly effective in treating musculoskeletal pain.[2]
3. **Cognitive Function and Brain Health**:
NIR light therapy has been investigated for its potential neuroprotective effects. It can enhance mitochondrial function, reduce oxidative stress, and improve cognitive performance in neurological conditions like dementia.[3]

4. **Skin Health**:
NIR light therapy promotes collagen production and improves skin elasticity, which can reduce signs of aging and enhance overall skin health. It is also used to treat conditions like acne and scars. [4]
5. **Improved Circulation**:
NIR light can enhance blood flow and oxygenation, which is beneficial for cardiovascular health and recovery from injuries. [5]
6. **Production of melatonin within the cell** NIR light it looks like produces melatonin at a cellular level. This melatonin is believed to be used as coolant by the mitochondria. In turn this reduces inflammation within the cell.[6][7]
7. **Reduction of symptoms in COVID19**
Fascinating work by an intensive care doctor found that used red and NIR light significantly reduced the symptoms of seriously ill patients. [8][9]
8. **Reduction of post prandial blood glucose**
A double blind study found that after meals red light being shone upon the lower back reduced blood sugar levels significantly. This is believed to be due to the cells working more efficiently at up taking the glucose hence there was less left in the blood stream.[10]

9. **May increase collagen production**
Research appears to indicate that controlled exposure to NIR and red light increases collages and reduces wrinkling in the skin.[11] NIR may also prepare the skin for UV light reducing the damaging impact of UV light.[12]
The areas that particularly interest me are the improvement in the function of mitochondria, efficiency with blood glucose, and the impact on the brain.
So what do we do with this information? It’s not practical to spend 50% of our time outdoors as our ancestors would have done unless you work outdoors and it will likely be a long time before the indoor light environment changes again. Research can take decades to filter through to action.
A first step would be to spend as much time outside as is practical for you and at minimum aim to get out into daylight most days ideally for some form of movement. Full spectrum bulbs are available and a good consideration if you spend most of your time indoors as are (if it’s within your budget) red light devices. However full spectrum bulbs although they release red light they do not have NIR. If there are rooms you spend a large amount of time in, it and NIR devices it might be worth considering switching back to the more efficient incandescent bulbs. In the US there is a bulb manufacturer making bulbs that are a LED plus a NIR filament combination which I would love to see available here. Interestingly because our mitochondria communicate with each other we don’t need more than a small amount of skin exposure to red light to reap some of the benefits.
It’s an interesting and relatively new field within health but maybe in a few years it will be as commonplace as discussions of any other health need. Perhaps we need to think of light as a nutritional need in the same way as water and food? It will be interesting to watch this area!
Due to all of the potential benefits of red and near infrared light I have a light panel installed on the gym wall. The NIR aspect is running throughout training sessions. For any clients who I feel will benefit from red light they have the opportunity to spend 5 minutes with their back to the panel after their session has finished. This is free of charge.
If you would like to have personal training in a private gym in Alnwick Northumberland please get in touch.
Or perhaps you would like to work with an online fitness coach competent in working with health issues and injuries.
[1] Mechanisms of low level light therapy. Hamblin, M. R., & Demidova, T. N. (2006).
[2] Efficacy of low-level laser therapy in the management of neck pain: a systematic review and meta-analysis of randomized placebo or active-treatment controlled trials. Chow, R. T., Johnson, M. I., Lopes-Martins, R. Â. B., & Bjordal, J. M. (2009
[3] Shining light on the head: photobiomodulation for brain disorders. Hamblin, M. R. (2016).
[4] The photobiological basis of low level laser therapy (LLLT). Calderhead, R. G. (2007).
[5] Red/near infrared light stimulates release of an endothelium dependent vasodilator and rescues vascular dysfunction in a diabetes model. Keszler A, Lindemer B, Weihrauch D, Jones D, Hogg N, Lohr NL. (2017)
[6] Melatonin: Both a Messenger of Darkness and a Participant in the Cellular Actions of Non-Visible Solar Radiation of Near Infrared Light. Tan DX, Reiter RJ, Zimmerman S, Hardeland R.
[7] Melatonin and the Optics of the Human Body. Zimmerman S, (2020)
[8] Light-Based Therapy: Novel Approach to Treat COVID-19. Azadeh SS, Esmaeeli Djavid G, Nobari S, Keshmiri Neghab H, Rezvan M. (2023)
[9] A geographical approach to the development of hypotheses relating to Covid-19 death rates. Margaret Skutsch,Roger D. Seheult,Jaime Loya. (2022)
[10] Light stimulation of mitochondria reduces blood glucose levels. Glen Jeffery. (2024)
[11] [11] Effects of Infrared Radiation on Skin Photo-Aging and Pigmentation. Lee JH, Roh MR, Lee KH.(2006)
[12] The effects of infrared radiation on the human skin. Luke Horton, Joshua Brady, Colin M. Kincaid, Angeli Eloise Torres, Henry W. Lim. (2023)
Image references
[1] Melatonin and the Optics of the Human Body. Zimmerman S, (2020)
[2] Shining light on the head: photobiomodulation for brain disorders. Hamblin, M. R. (2016).
[3]Light stimulation of mitochondria reduces blood glucose levels. Glen Jeffery. (2024)
[4]Melatonin and the Optics of the Human Body. Zimmerman S, (2020)

































