The Biology


Mitochondria are present in every cell in the human body, with multiple mitochondria present in many cells.

Mitochondria play a key role in regulating the ageing process. When their membrane potential and function declines, their production of adenosine triphosphate (ATP) reduces resulting in a fall in energy available to the cell. This drop off in energy causes a decline in cell health and ultimately cell death. This is particularly true in the central nervous system key structural and functional changes occur during ageing.

Over the years, there has been a lot of research in to ways to alter or stop these cellular changes, to slow the ageing process and improve quality of life in old age.

From genetic manipulations to changes in diet and from using pharmaceuticals and antioxidants to incorporating more exercise and lowering cardiovascular risk factors, all have attempted to extend life and reduce the adverse impact of age, Recently, photobiomodulation, the application of red to infrared light (λ=600-1000nm) on body tissues has been reported to alter the course of aged decline. These wavelengths are absorbed by cytochrome c oxidase, the rate limiting enzyme in mitochondrial respiration, increasing its activity along with mitochondrial membrane potential and ATP production .

The precise mechanisms used by photobiomodulation are unclear. Mitochondrial and physiological functions are improved, but increased ATP production alone is unlikely to underpin the physiological improvement, as this is relatively temporary. Hence, there are likely to be cascades of signalling between mitochondria and other structures including the nucleus and endoplasmic reticulum that have a wide ranging impact on metabolism that sustain longer term positive changes.

There is evidence that changes in mitochondrial function in one part of the body can influence those at other locations, and improvements in retinal pathology have been reported after photobiomodulation treatment away from the eyes [8]. However, data here are very limited.

In conclusion, photobiomodulation has been shown to alter the course of ageing in the central nervous system, by improving the survival and function of neurons and reducing gliosis and inflammation. These results in the laboratory are ripe for translation to the clinic, to determine whether this treatment effectively slows ageing in humans. Some of the key advantages of photobiomodulation therapy relate to its economy and safety, as it can be delivered with commercially available light emitting devices at energies well within the human safety range. Moreover, a major strength of this therapy is that it can offer a potential clinical application where there is little alternative available.