Sunlight & Light Therapy, Allies, or Foes?
For thousands of years, people have used sunlight as a means to aid health and even cure illness. But the concept has gone in and out of favor over the course of time.
Some of the logic related to sunlight began in China around 6,000 BC. At that time, Chinese architects began building homes to face south so that the sun would heat the interior, a practice that continues even today. While windows were likely no more than a gap in the wall at the time, you can still imagine families gathering around to soak up the light and heat. Finally, the trend of solar-heated homes began to catch on in Greece and even Rome. Learn more about solariums.
Then, in the 1900s, research by Augusta Rollier led to the establishment of solaria — buildings designed to optimize exposure to sunlight — throughout Switzerland for the express purpose of sunbathing, which provided impressive results for fighting tuberculosis, smallpox, lupus, and even chronic diseases like arthritis.
But by the middle of the 20th century, the American Cancer Society began demonizing sun exposure as a significant cause of skin cancer.
However, doctors, scientists, and clinical research is demonstrating that consistent exposure to sunlight is actually a critical component of overall health.
Almost all life on earth needs sunlight for many essential functions. It’s hard to ignore its importance for our emotional and physical health as well. We did not evolve in the darkness. The fact that our bodies use UV wavelengths to produce vitamin D has been well established. Read more about vitamin D here.
Is Sunlight Dangerous?
Several recent studies have come to the conclusion that consistent sunlight exposure actually reduces the chances of getting melanoma, and instead increases the survival rate. Also, throughout the ages, regardless of their geographical location, large groups of people have been exposed to nearly continuous sunlight. We evolved having sunlight.
So why did the melanoma epidemic not hit until the 1970s? And if sunscreen is the solution, why have melanoma rates increased over 200% since 1973 — even while the U.S. sunscreen industry has expanded from $18 million in 1972 to around $2 billion today? It’s hard to believe that sunlight was the major problem, nor sunscreen the solution.
A recent review of many such studies published in the European Journal of Cancer Prevention concluded that “there is accumulating evidence for sunlight as a protective factor for several types of cancer.” Sadly, many people still live under the incorrect premise that sunlight is damaging and harmful.
The reality is that we have become so disconnected from natural sunlight that our bodies aren’t equipped to handle its under-appreciated benefits. You may be surprised to learn that as your body gets sunlight in the morning, you can actually prepare your cells for the effects of UV light later in the day. And amazingly, the wavelengths in evening sunlight have a natural repairing effect. That’s because red and infrared wavelengths, which are delivered in higher concentrations in the morning and evening, have the unique ability to boost mitochondrial function. This, in turn, enables our cells to both withstand the stresses — and harness the benefits — of UV light. In addition, exposure to sunlight as the seasons change allows our skin to develop a tan, which also forms a natural protection against the stronger UV wavelengths during the summer months.
So the evidence suggests that sunlight might not be the bad guy, after all, we just need to develop a better understanding of how sunlight affects our bodies, and how to harness its potential to improve our health.
The Benefits of Receiving Sunlight
Our retinas are connected directly to the suprachiasmatic nuclei of the hypothalamus gland, which acts as the master circadian pacemaker of the body. Because of this, light received through your eyes plays a critical role in hormonal functions including melatonin production, which regulates our sleep. Quite literally, your body knows to shut off this hormone through exposure to morning sunlight. This type of exposure early in the day also helps produce melatonin later in the evening, when light is absent. Even more amazing, the hypothalamus gland, which is controlled by light, is responsible for controlling body temperature, thirst, hunger, and emotional activity — in addition to regulating your hormones and circadian rhythm!
Dopamine is another chemical that is regulated by light and released in the brain. It functions as a neurotransmitter and is closely tied to the emotions of reward and pleasure. In fact, many addictive drugs increase dopamine neuronal activity. Not surprisingly, studies have demonstrated that light exposure is tied to increased dopamine production. So it’s clear that light received through our eyes plays a much more powerful role than most of us realize.
How You Can Benefit from More Light
Getting as much natural sunlight as possible is clearly important. For example, receiving morning sunlight correctly sets your circadian rhythm. However, nowadays, most of us find it challenging to spend hours in the sun — at the right time of day — on a regular basis. Our busy schedules just don’t allow for more time in the sun. In fact, it’s estimated that Americans spend more than 90% of their time indoors.
Because this is the case for most of us, a great way to receive the healthy wavelengths of light is by using a light therapy device. One way to think of red light therapy is as a supplement for your health. Dietary supplements help fill out the vitamins your body needs, and regular red light therapy sessions help fill in the lack of natural light our bodies need.
There are many proven benefits of receiving certain wavelengths of natural sunlight directly through our skin and bodily tissues. One aspect that has received little attention is related to the cellular processes affected by certain wavelengths of light.
Researchers in the field of light therapy, or photobiomodulation (PBM), have discovered some incredibly powerful functions derived from wavelengths of light in the optimal window. Improved mitochondrial function, which impacts virtually all cellular metabolic activity, has been widely demonstrated to improve health in a number of ways — including enhanced muscle recovery, reduced inflammation, increased testosterone, and better overall skin health.
In addition to these clinically-proven benefits, several studies have demonstrated that certain wavelengths of light can increase blood flow and assist in the formation of new capillaries. Dr. Gerald Pollack explores this concept in more detail in his award-winning book, The Fourth Phase of Water.
In conclusion, scientists are really just beginning to understand the crucial role that light plays in our overall health. But recent evidence strongly suggests that exposing our bodies to the right kind of light can lead to some wonderful benefits.
Scientific Sources and Medical References:
Woloshyn, T. (2011). Our Friend, the Sun: Images of Light Therapeutics. [eBook] Osler Library of the History of Medicine. Available at: https://www.mcgill.ca/library/files/library/osler-ourfriendsun.pdf.
Melanoma Stats, Facts, and Figures [Web Log Post]. Available at https://www.aimatmelanoma.org/about-melanoma/melanoma-stats-facts-and-figures.
Sunscreen Report. [eBook] Available at: https://finalstepmarketing.com/wp-content/uploads/2015/07/Sunscreen-Market-Analysis.pdf.
Berwick, M., et al. Sun Exposure and Mortality From Melanoma. J Natl Cancer Inst. 2005 Feb 2;97(3):195–9.
van der Rhee H, Coebergh JW, de Vries E. Sunlight, vitamin D and the prevention of cancer: a systematic review of epidemiological studies. Eur J Cancer Prev. 2009 Nov;18(6):458–75.
Avci, P, et. al. Low-level (light) therapy (LLLT) in skin: stimulating, healing, restoring. Semin Cutan Med Surg. 2013 Mar;32(1):41–52.
Cawley, EI, et al. Dopamine and light: dissecting effects on mood and motivational states in women with subsyndromal seasonal affective disorder. J Psychiatry Neurosci. 2013 Nov;38(6):388–97.
Ihsan FR. Low-level laser therapy accelerates collateral circulation and enhances microcirculation. Photomed Laser Surg. 2005 Jun;23(3):289–94.
Klepeis NE, Nelson WC, Ott WR, et al. The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants. J Expo Anal Environ Epidemiol. 2001 May-Jun;11(3):231–52.