We are still on the threshold of fully understanding the complex relationship between light and life, but we can now say, emphatically, that the function of our entire metabolism is dependent on light. -- Fritz-Albert Popp
At the dawn of the twenty-first century, the importance of light for our health and well-being has been confirmed by modern science. Today there is a great confluence of discovery and invention. Two extraordinary discoveries in biology have been brought to the study of light: the nonvisual optic pathway and photobiomodulation. At the same time, technological advancement is leading to new types of light sources, more powerful and more flexible than ever, and to new biomedical measuring devices that can assess the effects of light in minute detail.
A new era of light medicine has arrived.
The Future of Light Medicine
Being at the frontier usually means being the first to confront obstacles. Despite light medicine’s demonstrated successes, the fact remains that it has not yet found its rightful place within the medical system in terms of recognition from both health professionals and the general public.
The challenges are scientific as well as financial. The medical world is largely controlled by the pharmaceutical industry, and light does not seem to lead to treatments as lucrative or patentable as those of pharmacology. Dr. Thierry Patrice, a leading pioneer of Photodynamic Therapy (PDT), points to one of the main obstacles to its widespread acceptance:
What makes PDT a promising medical procedure is its cost-effectiveness, which has been documented in various medical fields. However, the structure of medical expenses in our developed countries, whatever the level of analysis—for instance big-pharma companies, hospitals, doctors, or insurance companies—is not in favor of cheap treatment modalities. Each group with the exception of patients has a direct interest in using expensive methods.... Thanks to the debt crisis, in the future, one can expect a change in the reimbursement philosophy of health expenditures in a way that would reinforce PDT. (Hamblin and Huang 2013)
Light medicine is still young, and it is evolving rapidly. Even if it is still only in its infancy, its day is definitely coming. Here are just a few examples of what is in store for us:
Bright light therapy is no longer just seasonal.
Until now, bright light therapy has been known for its effectiveness in treating SAD. But an article published in the American medical journal JAMA Psychiatry has caused quite a stir among mental-health professionals. Lam et al. (2016) showed that bright light is more effective than one of the most common pharmacological antidepressants (fluoxetine, better known under the brand name Prozac) in people suffering from major depressive disorders.
Moreover, two important meta-analyses of the treatment of nonseasonal depression with bright light appeared at about the same time: that of Perera et al. (2016), which reviewed twenty-one studies, and that of Alotaibi, Halaki, and Chow (2016), which covered twenty-four. Both reports concluded that though the accuracy of the published studies was not perfect, a significant positive effect has been clearly established.
The benefits of bright light are therefore no longer limited to seasonal disorders, and its field of application is growing. In one of the most recent examples, Valdimarsdottir et al. (2016) has been helping cancer survivors overcome their depression with the use of bright light. In another study, Sit el al. (2017) found bright light therapy effective in increasing the remission rate of patients with bipolar disorder. Intriguingly, their best results were obtained by administrating the bright light at midday rather than in the morning, as is the norm with SAD treatment, indicating that bright light therapy still holds many secrets.
New photoactive agents are coming from the ocean.
The latest research into the improvement of photosensitizing agents for PDT involves more and more complex technologies, such as the use of nanoparticles. In this regard analysis of photoactive molecules already present in nature has provided inspiration.
In collaboration with IFREMER (Institut Français de Recherche pour L’exploitation de la Mer), a French institute that undertakes research and expert assessments to advance knowledge on the oceans and their resources, researchers studied 140 types of marine algae (Morlet et al. 1995). Only 2 to 5 percent of the samples were expected to be photoactive, but it turned out that photosensitivity was detected in over 50 percent, and in some by a factor of thirty times over traditional photosensitizing agents. Elucidating the mysteries of these molecules will undoubtedly enrich the field of light medicine.
One of the latest trials using such new seabed-derived photosensitizing agents has shown great success in treating prostate cancer. Involving over four hundred patients, the study applied a PDT variant called vascular-targeted photodynamic therapy (VTP), in which the photosensitizing agent was injected in the bloodstream. According to lead investigator Mark Emberton, of University College London Hospital (UCLH), half of the patients treated with this new technique went into complete remission and were thus able to avoid using more invasive standard methods (Azzouzi et al. 2016).
Light is being introduced through the nose and ears.
We know that light can produce effects through the visual system, the skin, and the skull (with near-infrared laser transmission). But researchers are exploring other ways to bring light into the body, illustrating what the future could hold.
Intracranial low-intensity laser therapy involves the application of light in the nasal cavity. Its use is relatively common in China, where Liu et al. (2012) have been studying its effects for many years. Their studies have found it to be valuable for cardiovascular and cerebral disorders, and it is also used for many other ailments, including insomnia, migraine, and influenza, and for neuropathic and cognitive problems.
With its highly vascularized mucous membranes, the nasal passages are ideal for phototherapy because they allow for direct irradiation of the blood. But Dr. Liu suspects that the effects of this light probably go beyond this. He sees a possible influence on the convergence of six meridians that according to traditional Chinese medicine pass through the nose.
Other therapists have studied the application of light in the auditory canal as an extension of research on transcranial light therapy. Since the ear canal passes through the thick bones of the skull, it is a logical pathway for irradiating the brain’s neurons. This is what Jurvelin et al. (2014) tested in a study with patients suffering from SAD.
Positive results comparable to those achieved with the use of a light box as in standard bright light therapy were obtained in this investigation. Furthermore, an intriguing finding is that extraocular light does not seem to influence the secretion of melatonin, a factor normally considered to be of major importance in the classical bright light therapy treatment for SAD.
Light could be an effective treatment for Parkinson’s disease.
In the 1980s, French neurosurgeon Alim Louis Benabid began to develop deep brain stimulation, a revolutionary treatment for Parkinson’s disease and other movement disorders based on electrical stimulation of the affected neurons.
Dr. Benabid is now exploring a new type of treatment based on the ability of infrared light to regenerate neurons through photobiomodulation. Transcranial irradiation cannot suffice in this case since the zones that must be reached are deeper than the few centimeters of penetration achieved with near-infrared laser transmission. Dr. Benabid proposes to bring light directly through an optic microfiber inserted into the brain.
Successful trials have been performed on mice and more recently on monkeys (Darlot et al. 2016). Though this is obviously an invasive technique, it offers the extraordinary perspective of not only reducing the neuronal degradation brought on by Parkinson’s, but also of preventing it and one day possibly even reversing it.
Light could be used to treat Alzheimer’s disease.
A remarkable result was obtained by a Massachusetts Institute of Technology team of researchers after they exposed mice suffering from Alzheimer’s disease to flickering light. They found that flickering light in the gamma brain-wave range (specifically, at 40 Hz) significantly reduced the amyloid plaque buildup in the brain that is associated with Alzheimer’s (Iaccarino et al. 2016).
This unexpected finding can be better understood when one considers the ability of flickering light entering through the eyes to entrain brain waves to resonate at the driving frequency (see chapter 9). In the progression of Alzheimer’s, a reduction in gamma waves precedes the formation of harmful amyloid plaques in the brain, ultimately leading to a decline of learning and memory skills. The 40 Hz flickering light succeeded in reversing this trend, both restoring higher levels of gamma brain waves and attenuating the amyloid load.
While it is too early to know how this might translate into actual treatment for humans, the potential for such a noninvasive and easily accessible light technique is enormous.
©2018 by Anadi Martel.
Reprinted with permission of the publisher,
Healing Arts Press. www.InnerTraditions.com
Light Therapies: A Complete Guide to the Healing Power of Light
by Anadi Martel
(Originally published in French: Le pouvoir de la lumière: À l'aube d'une nouvelle médecine)
A comprehensive guide to the therapeutic benefits of light and color and how they affect our physical and psychological well-being. * Shares scientific research on how different wavelengths of light influence our cells, brain function, sleep patterns, and emotional stability * Examines several forms of light therapy, including chromotherapy, heliotherapy, actinotherapy, and thermotherapy * Explains how to use light and color therapy, maximize the benefits of sunlight, and avoid the health risks of new light sources such as compact fluorescents and LEDs.
About the Author
Anadi Martel is a physicist and electronics designer, who has acted as a consultant for IMAX, Cirque du Soleil, and the Metropolitan Opera of New York. For more than 30 years he has researched the therapeutic properties of light and the interaction between technology and consciousness, leading to the creation of the Sensora multisensorial system. His sound spatialization devices have been used around the world, including by NASA. He serves as President of the International Light Association (ILA) and lives in Quebec.