I can understand the skepticism about the biological effect of red lights, because that’s where I started from. It seemed too good to be true. However, there is a wealth of excellent quality research out there, and the evidence is compelling that red and near infrared lights protect existing neurones, and can stimulate new neurones to be created, stimulate blood vessels to increase connections- neuroprotection, neurogenesis and angiogenesis.

The common assumption is that red and near infrared lights must penetrate to the deepest part of the brain to have any effect on Parkinson’s disease. We know that the red and near infrared lights can penetrate to the outer one centimetre or so of the brain tissue, but the lights don’t reach the substantia nigra, tucked deeply in the basal ganglia.

But both animal and human experience shows that the red/ near infrared lights have a direct and indirect effect, and in humans the indirect effect can be powerful. The indirect effect is mediated by one or more of the white blood cells in the circulation – the immune cells. Somehow they pick up a pulse of red light and carry the energy from that light pulse and deliver it to a distant and distressed part of the body. A bit like an ambulance carrying and delivering life-saving medication.

The big learning, though, from all the observations of people using daily lights is the significant effect the lights have on non-motor symptoms of PD. Maybe this is related to the direct effect of the red lights on the outer part of the brain. There are consistent findings of improvements in fatigue, anxiety, depression, sleep quality, facial animation, auditory processing, apathy, the senses of smell and taste and the capacity for joy.

The more people with PD I see using lights, the more convincing the findings of non-motor or non-movement symptoms improvement. This is an important observation because none of the standard PD medications has any effect on the non-motor symptoms. And the non-motor symptoms are the most predictive of quality of life for people with Parkinson’s.

People with Parkinson’s disease – and their carers – all say that the non-motor symptoms have the biggest impact on quality of life

Here are a couple of blog posts:

Apathy – Link

Sleep – Link

I’ve uploaded some research papers to the blog – below are the links to the blog posts where the journal articles can be downloaded.

Recent Spanish pilot study looking at the effects of red lights on the motor symptoms of PD: Link

Case studies of people with PD using daily transcranial red lights:Link.

Useful summary article by Prof John Mitrofanis: Link

Summary of a recent presentation by Prof Mitrofanis:Link