How does Red and Non-Infrared Light Therapy work?
Red and near infrared light - what makes them different?
Red and near infrared light have two key properties:
They penetrate into the body - through skin, fat, muscle and even bone. Other wavelengths (eg blue or green) can’t do this.
Every cell in our body can respond to the pulse of red or near infrared light. Each cell has a little entity called a mitochondrion - it is basically a battery, responsible for providing energy to fuel the cell’s activities. In the mitochondrial wall, there are specific proteins that react to red and near infrared light. When red and near infrared light shines, the protein’s responses set off a series of chemical changes within and outside the cell. These changes are good ones – they all make the cell work better in a variety of ways. When mitochondria meet red and near infrared light, the cell batteries are recharged. This is called the direct effect of red and near infrared light.
The implications of these two properties are profound:
Red and near infrared light can directly affect cells, even those two centimetres below the skin surface – it can penetrate quite a way. This means that every mitochondrion gets an energy boost. This also means that all the cells suddenly get active. Very active.
When the mitochondrial proteins are given a dose of light, a series of chemical cascades are kick-started. These chemical cascades have three essential outcomes:
They make the cell active and able to do whatever it is supposed to do. This battery re-charge protects the cell and makes it function normally for a while. In the brain, the effect is called neuroprotection.
They stimulate the cell to begin the process of making new cells. This is good, as new cells mean more action. In the brain, this is called neurogenesis.
They change the chemical soup outside the cells, and this:
Makes the blood vessels sprout new branches. This is called angiogenesis.
Stops the inflammatory response, and the release of the kind of chemicals that cause pain and do damage to the tissue. This is called the anti-inflammatory effect.
The direct effect is very powerful. Red and near infrared lights on the head result in happier functioning brain cells (neuroprotection), new brain cells being generated (neurogenesis), new blood vessels sprouting and bringing more oxygen to the cells (angiogenesis) and as well as acting to reduce inflammation.
Click the headings below for more information on red and near infrared light therapy:
+ What is the definition of red and near infrared light?
The definition of red and near infrared light: the wavelengths between 600 nanometers and 110 nanometers. (A nanometer is unbelieveably tiny – a millionth of one millimetre. The abbreviation for nanometer is nm.
+ How long does the effect last?
It seems that some chemical cascades last seconds, others minutes, others hours or days and maybe even weeks. Red and near infrared light is like a battery boost. This means that to use red and near infrared light to improve cell function, it needs to be used at least once daily.
+ What is the direct effect of red and near infrared light?
The direct effect occurs when the red and near infrared light shines on the cell, and it is described in detail here: What is the big deal about red and near infrared light?
+ What is the indirect effect of red and near infrared light?
The indirect, or abscopal effect of red and near infrared light has only recently been described. This was first picked up in an ingenious study by Dr Dan Johnstone and the Mitrofanis team at University of Sydney (put hyperlink to the research page – the helmet study). This study showed that shining red and/or near infrared light on a distant part of the body (not on the head!) can improve Parkinson’s symptoms. It sounds weird, but it is real.
It seems that the power of the indirect effect is different for each person and probably depends on things like age, state of health, how far the disease, whether it is Parkinson’s (hyperlink) or Alzheimer’s (hyperlink) or other disease has progressed and probably lots more.
Just how this indirect effect works is still being worked out. Initially it was thought that some of the immune cells, or white blood cells in the bloodstream picked up the energy pulse and then transported it to an area of the body that needed some help. That might indeed by the case, but we also know that mitochondria have a life that until recently had been secret. Not all of them are trapped inside cells. A lot live outside cells. It seems that a very large number of active and healthy mitochondria live a nomadic life in the bloodstream, happily circulating all over the body. It is very likely that these free-range mitochondria drive the indirect effect. It is an exciting new research area.
+ Which is more important, the direct effect or the indirect effect?
Both are equally important. For example in Parkinson’s disease, you could treat it by shining light on your left big toe. There will be a small effect on your brain, and your left big toe will enjoy itself. But the effect on your brain will be significantly bigger and better by shining light on your head, as then you give a large number of brain cells a battery boost. This is explained further here (Parkinson’s text).
The head has a lot of blood vessels – far more than your left big toe. So shining light on your head is an efficient use of resources. You get the direct effect on all the brain cells in the outer part of the brain, and you recharge a lot of free-range mitochondria happily tootling in the dense clump of blood vessels in the scalp.
+ How far does the red and near infrared light penetrate into the brain?
It’s likely that red and near infrared light can shine directly onto the brain cells in the outer two or more centimetres of brain tissue. That’s a lot of brain cells. Research has shown that light penetrates further if the whole head is covered with light.
Here is a graphic from a 2015 research paper, modelling the effect of shining red and near infrared light onto the head. On the right, you can see how far a single light source penetrates into the head. The most penetration is in red, and the blue is the least. There’s a little splodge of red, but not much. Compare this with the graphic on the left where there is light shining all over the head (as with the Coronet). You can see how much further the light penetrates into the brain.
From: Lan Yue and Mark S. Humayun "Monte Carlo analysis of the enhanced transcranial penetration using distributed near-infrared emitter array," Journal of Biomedical Optics 20(8), 088001 (7 August 2015). https://doi.org/10.1117/1.JBO.20.8.088001
+ Can red and near infrared light be used for diseases outside the brain?
Indeed. There is a lot of research coming out now showing that regular use of red and near infrared light has a range of useful effects.
Muscles: using it on your muscles before exercises increases endurance and reduces the risk of injury. Not surprisingly, red and near infrared light is being used by elite athletes. Heart: as with other muscle fibres, it improves the function of heart cells. It is currently being trialled in stent procedures. Arthritic joints: more and more evidence is coming in showing that using it daily will help reduce inflammation, reduce pain and improve movement. Check out the very first post in the redlightsonthebrain blog.
Depression: again, more and more evidence is accumulating to show that daily trans-cranial lights reduces depression and anxiety symptoms. Depression is increasingly thought to be a result of inflammation in the brain, and can respond well to daily red and near infrared light use.
Wound healing: definitely. Again, the research evidence is huge and some hospitals now incorporate it in their wound management protocols.
Pain: definitely. Again, the research evidence is rapidly increasing, and the anti-inflammatory effect is well documented. With the opioid crisis, red and near infrared lights offer hope without any side-effects.