By Marc Sorenson, EdD, Sunlight Institute…..
Before proceeding with the discussion on sunlight addiction, it is important to review the truth about sunlight and melanoma, to understand why sunlight addiction may be a good thing.
A recent report on ultraviolet light and addiction is obviously meant to be a hit piece regarding sunlight exposure and tanning, as seen in the opening statement: “Despite widespread awareness that UV exposure is a major risk factor for all common cutaneous malignancies, skin cancer incidence relentlessly increases by ~3% per year.”
The “all common cutaneous malignancies” portion of this statement, of course, is patently false. Whereas the relatively benign common skin cancers are increased by exposure to sunlight, melanoma is increased by avoiding the sun. If the dramatic increase in melanoma over the past century were due to sunlight exposure, then sunlight exposure must also have increased dramatically during that time. To determine whether that has happened, we analyzed data from the Office of Occupational Statistics and Employment Projections, Bureau of Labor Statistics, (BLS) to determine if there was an increase or decrease in human sunlight exposure during the years from 1910 to 2,000. The statistics showed that indoor occupations such as “professional, managerial, clerical, sales, and service workers grew from one-quarter to three-quarters of total employment between 1910 and 2000.” BLS also stated that during the same period, the outdoor occupation of farming declined from 33% to 1.2% of total employment, a 96% reduction. The data also showed an approximately 66% decline in the occupation of farmers and 50% of the decline in the occupation of farm laborers.
The Environmental Protection Agency also determined that as of 1986, about 5 percent of adult men worked mostly outside, and that about 10 percent worked outside part of the time. The proportion of women who worked outside was thought to be even lower. These data demonstrate a dramatic shift from outdoor, sun-exposed activity to indoor, non-sun-exposed activity during the mid-to-late 20th Century.
Despite these facts, the Melanoma International Foundation (MIF) has stated that melanoma has increased by 30 times (3,000%) just since 1935! Here is the statement by the MIF: “Melanoma is epidemic: rising faster than any other cancer and projected to affect one person in 50 by 2010, currently it affects 1 in 75. In 1935, only one in 1,500 was struck by the disease.” Indeed, the American Cancer Society in 2014 reported that one in 50 now contracts the disease. That exponential increase in melanoma has been accompanied by a profound decrease in sunlight exposure, yet sunlight or other UV exposure is blamed for the melanoma increase—a totally counterintuitive argument! I submit that not only is sunlight not responsible for the exponential increase in melanoma, but that the decrease in sun exposure may be a major cause of that increase.
Here are other facts that belie the idea that melanoma is caused by sunlight exposure:
- Outdoor workers, while receiving 3-9 times the UVR exposure as indoor workers,  have had no increase in melanoma since before 1940, whereas melanoma incidence in indoor workers has increased steadily and exponentially.
- Most melanomas occur on areas of the body that are seldom or never exposed to the sunlight.  
- The use of sunscreen, which has increased steadily, has not resulted in a decrease in melanoma. In fact, melanoma has increased as sunscreen use has become more widespread. Since sunscreens block sunlight, it is evident that at best they are a waste of money and at worst may be contributing to the increase in melanoma.
Now, let’s discuss the research on the aforementioned addiction to sunlight. The researchers conducted various experiments on mice that showed behavior choices, such as desiring lighter rather than darker environments, were increased by regular exposure. These behavior choices were mediated by β-endorphins, peptide hormones which are similar to opiates. So is this all bad? This marvelous product, β-endorphin, is one of the feel-good hormones that decreases pain and increases a sense of well-being. The case the researchers make regarding addiction to sunlight is compelling, and why not? Sunlight exposure causes vitamin D production in the skin, which is essential to human health; it also stimulates the production of nitric oxide, which relaxes our vessels and lowers our blood pressure; it stimulates the production of serotonin in the brain, which is another feel-good hormone necessary for a happy mood and wellbeing. And considering the myriad additional effects of sunlight on health, including the prevention of cancer, the prevention and reversal of bone diseases and the reduction of heart disease, could it not be part of God’s (or Nature’s) master plan to develop a positive addiction to sunlight so than our health could be enhanced? I am a sunlight addict, and expose myself to it regularly for two reasons: (1) It marvelously improves my mood and (2) it protects me from disease and weakness. I am a light-skinned, blue-eyed Caucasian who has spent much of my seven decades on this earth seeking the sun. Yet, there have been no melanomas or even common skin cancer.
Nevertheless, the researchers summarize their paper on sun addiction with the following: “While primordial UV addiction, mediated by the hedonic [pertaining to pleasure] action of β-endorphin and anhedonic effects of withdrawal, may theoretically have enhanced evolutionary vitamin D biosynthesis, it now may contribute to the relentless rise in skin cancer incidence in man.”
That summary statement is claptrap, as can be seen by the research on melanoma and sunlight presented above. If sunlight is addictive and helps me to avoid melanoma, heart disease, bone loss and other maladies, I can only say, “hooray for the addiction!”
 Gillian L. Fell, Kathleen C. Robinson, Jianren Mao, Clifford J. Woolf, and David E.
Fisher. Skin β-endorphin mediates addiction to ultraviolet light. Cell. 2014 June 19; 157(7): 1527–1534.
 Ian D. Wyatt and Daniel E. Hecker. Occupational changes in the 20th century. Monthly Labor Review, March 2006 pp 35-57: Office of Occupational Statistics and Employment Projections, Bureau of Labor Statistics
 U.S. Congress, Office of Technology Assessment, Catching Our Breath: Next Steps for Reducing Urban Ozone, OTA-O-412 (Washington, DC: U.S. Government Printing Office, July 1989).
 Melanoma International Foundation, 2007 Facts about melanoma. Sources: National Cancer Institute 2007 SEER Database, American Cancer Society’s 2007 Facts and Figures, The Skin Cancer Foundation, The American Academy of Dermatology.
 American Cancer Society. Melanoma Skin Cancer Overview 9/16/2014. Accessed on 9/23/2014 at http://www.cancer.org/cancer/skincancer-melanoma/overviewguide/melanoma-skin-cancer-overview-key-statistics
 Godar D. UV doses worldwide. Photochem Photobiol 2005;81:736–49.
 Thieden E, Philipsen PA, Sandby-Møller J, Wulf HC. UV radiation exposure related to age, sex, occupation, and sun behavior based on time-stamped personal dosimeter readings. Arch Dermatol 2004;140:197–203.
 Garland FC, White MR, Garland CF, Shaw E, Gorham ED. Occupational sunlight exposure and melanoma in the USA Navy. Arch Environ Health 1990; 45:261-67.
 Rivers, J. Is there more than one road to melanoma? Lancet 2004;363:728-30.
 Crombie, I. Racial differences in melanoma incidence. Br J Cancer 1979;40:185-93.
 Phillippe Autier. Do high factor Sunscreens offer protection from melanoma? West J Med. 2000 Jul; 173(1): 58.
By Marc Sorenson, EdD
Drs. Asta Juzeniene and Johan Moan wrote a paper in 2012 that beautifully summarizes the effects of sunlight beyond the production of vitamin D. Here are the highlights of their paper, as stated in the abstract. They discuss the separate affects of Ultraviolet B light (UVB) and ultraviolet A light (UVA), which are, of course, components of sunlight.
- UVB induces cosmetic tanning (immediate pigment darkening, persistent pigment darkening and delayed tanning).
- UVB-induced, delayed tanning acts as a sunscreen.
- Several human skin diseases, like psoriasis, vitiligo, atopic dermatitis and localized scleroderma, can be treated with sunlight or artificial UV radiation (phototherapy).
- UV exposure can suppresses multiple sclerosis independently of vitamin D synthesis.
- UVA generates nitric oxide (NO), which may reduce blood pressure and generally improve cardiovascular health.
- UVA induced NO may also have antimicrobial effects.
- UVA induced NO may act as a neurotransmitter.
- UV exposure may improve mood through the release of endorphin.
It wasn’t mentioned in the paper, but we now know that sunlight also helps generate serotonin in the brain, which improves mood, and outside the body it is a potent disinfectant (see my recent blogs on those subjects). So those who claim that sunlight is harmful in any amount, must be living on a different planet. Embrace the Sun, but never burn.
 Asta Juzeniene and Johan Moan. Beneficial effects of UV radiation other than via vitamin D production. Dermato-Endocrinology 4:2, 109–117; April/May/June 2012.