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, Sunlight Institute
In a new media release from Toronto, the Vitamin D Society asserts that “The importance of natural sunlight to human life cannot be understated.” It goes on to quote Dr. Reinhold Vieth, a scientist and professor at the University of Toronto. “There really is no substitute for natural sunlight in human health. Your skin is like a solar receptor and has the amazing capacity to manufacture all of the vitamin D your body needs. Everyone has the capability to generate vitamin D.”
There is a problem, however, as I posted recently. About a third of Canadians, about 12 million people, do not meet the minimum Health Canada guidelines for vitamin D levels. The reason? Sunlight deficiency.
Perry Holman, executive director of the Society, states that “This is not a call for people to ignore the warnings about over-exposure to sunlight but a call for people to exercise common sense and ensure they are not shutting themselves out from the vital health benefits of natural sunlight.”
Of course, in the winter, when no vitamin D production is available, it will be necessary to find another source of vitamin-D stimulating light. Sunlamps are ideal, provided they produce UVB light.
Also remember, that during winter, sunlight still raises serotonin levels and produces nitric oxide, both of which are necessary to human health. The value of sunlight goes far beyond its ability to promote vitamin D production in the skin.
For more information on the Vitamin D Society, visit www.vitamindsociety.org.
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.
By Marc Sorenson, EdD, Sunlight Institute
Does sunlight have an influence on the risk of having a stroke? It does.
Interesting research had as an objective to determine whether long-term or short-term sunlight exposure affected stroke incidence.1 Measurements of sunlight exposures were taken for 15-,10-,5-,2-, and 1-year exposures to sunlight among 16,606 people who were free on any coronary disease. It was found that shorter exposure periods exhibited slightly stronger protective relationships against stroke, but both long- and short-term exposures were effective. Those who were below the median sunlight exposure had an increased risk of stroke of 61%. The researchers said that they did not know the biological pathways for the protective relationship, but I surmise that the answer is sunlight-induced nitric-oxide production, which keeps the blood pressure down and keeps the vessels flexible.
Whatever the mechanism by which sunlight protects us against stroke, let’s celebrate the fact that the protection is available.
1. Kent ST, McClure LA, Judd SE, Howard VJ, Crosson WL, Al-Hamdan MZ, Wadley VG, Peace F, Kabagambe EK. Short-and long-term sunlight radiation and stroke incidence. Ann Neurol. 2013 Jan;73(1):32-7.
By Marc Sorenson, EdD Sunlight Institute
Recent research, again involving Dr. Richard Weller, demonstrates that Sunlight exposure may prevent liver inflammation in non-alcoholic fatty liver disease (NAFLD), which is the most prevalent liver disorder in western countries. The authors of this research state then state the following possible mechanism: “Following exposure to sunlight-derived ultraviolet radiation (UVR), the skin releases anti-inflammatory mediators such as vitamin D and nitric oxide.”
Though there has been no proof that sunlight works for humans (no research yet), the authors indicate that animal studies suggest that exposure to sunlight (UVR), can prevent the development of NAFLD.
They also note that most of the credit for these positive results has focused on vitamin D, yet clinical trials have yet to demonstrate a clear, beneficial effect of supplementation; therefore, they suggest that other mediators such as nitric oxide may be important. This is another of those studies that demonstrates the possibility that sunlight has positive affects on a disease independently of vitamin D. Future research may clarify that idea.
Until then, regular sun exposure may be good insurance for a healthy liver.
 Gorman S, Black LJ, Feelisch M, Hart PH, Weller R. Can skin exposure to sunlight prevent liver inflammation? Nutrients 2015 May 5;7(5):3219-39.
Marc Sorenson, EdD, Sunlight Institute.
Anything that causes arterial plugging or prevents the relaxation of blood vessels can contribute to cardiovascular diseases (CVD). Poor diet, little exercise and lack of sunlight exposure form a combination that devastates vessel health and reduces the flexibility of those vessels. Among the CVD are ischemic heart disease, intermittent claudication (painful oxygen restriction to the legs), ischemia of the brain leading to strokes, peripheral artery disease and erectile dysfunction. Yes, I said erectile dysfunction.
ED is considered one of the major predictors of CVD.[i] It is caused by inability of the corpus cavernosa, two cylindrical chambers that run the length of the penis, to become engorged with blood, causing erection. When the process takes place normally, the cavernosa are stimulated by nitric oxide (NO), they then relax, and blood flows into the penis, allowing erection to take place. Therefore, erection is a vascular event.[ii] The same effect is seen in blood pressure decreases caused by NO after sunlight exposure. Ultraviolet A (UVA) light stimulation of the skin causes the release of NO from pre-formed stores of NO in the skin. NO is a potent vasodilator, and when it is released into the arteries by UVA stimulation, causes increased blood flow and lowers blood pressure.[iii] The mechanism is much the same in both instances. This is another example of sunlight enhancing health without the benefit of vitamin D. UVA light, that stimulates nitric oxide release, does not stimulate the skin to produce vitamin D.
An early study assessed the affect of ultraviolet light (UV) exposure to cavernosal strips, which were obtained from men during penile prosthetic surgery.[iv] The strips showed relaxation in response to UV, and the relaxation increased with the duration of exposure. We expect that sunbathing, which would profoundly increase NO in the circulation, would also vasodilate the cavernosa to allow erection. The same nitric oxide mechanism that lowers blood pressure, would seem to be a good method to treat ED. After all, drugs for ED, such as Viagra and Cialis, work by enhancing the effects of nitric oxide.[v] Sunlight is free and is a much better choice.
[i] Pastuszak AW, Hyman DA, Yadav N, Godoy G, Lipshultz LI, Araujo AB, Khera M. Erectile dysfunction as a marker for cardiovascular disease diagnosis and intervention: a cost analysis. J Sex Med 2015 Apr;12(4):975-84.
[ii] Marc Sorenson and William B. Grant. Does vitamin D deficiency contribute to erectile dysfunction? Dermatoendocrinol 2012 Apr 1; 4(2): 128–136.
[iii] Liu D, Fernandez BO, Hamilton A, Lang NN, Gallagher JM, Newby DE, Feelisch M, Weller RB. UVA irradiation of human skin vasodilates arterial vasculature and lowers blood pressure independently of nitric oxide synthase. J Invest Dermatol. 2014 Jul;134(7):1839-46.
[iv] Kim SC, Oh CH, Park JK, Lee MY, Uhm DY. Effects of ultraviolet light on the tension of isolated human cavernosal smooth muscle from non-diabetic and diabetic impotent men. Urol Res. 1997;25(2):149-52.
[v] Mayo Clinic Online. http://www.mayoclinic.org/diseases-conditions/erectile-dysfunction/in-depth/erectile-dysfunction/art-20047821. Accessed July 3, 2015.
Marc Sorenson, EdD, Sunlight Institute
The Daily Mail, from the UK, recently posted an article regarding sunlight and fertility that should catch some interest.
Infertility is a problem that causes some couples to seek help from in vitro fertilization (IVF). New research shows that sunlight exposure for a month prior to the procedure increase the odds of success by 35%. Dr. Frank Vandekerckhove, who reported the research, looked at the IVF results of about 6,000 women and compared the dates of their treatment with weather conditions. The more sunshine, the greater likelihood of becoming pregnant. Dr. Vandekerckhove said that sunshine a month before conception probably helped a woman’s eggs to mature. He also mentioned that there is no reason to think that a burst of sunshine won’t also help women trying to get pregnant naturally.
There is nothing really new about the effects of sunlight on fertility, and this work by Vandekerckhove is not the first to establish the link of sunlight to IVF. Much has also been studied regarding natural, non- laboratory fertility. Low vitamin D, which is primarily a result of low sunlight exposure, is closely related to the ability to conceive in both women and men. Couples spend thousands of dollars on fertility clinics and IVF when perhaps all they need is some time in the sun.
In an article posted on Emax health, entitled Sex in the Sun May Increase Your Fertility it is pointed out that approximately 15% of couples who want to conceive are plagued by problems of fertility. Drs. Elisabeth Lerchbaum and Barbara Obermayer-Pietsch, in 2012, conducted a review of articles on vitamin D and fertility and came to these conclusions: “VDR knockout mice [mice whose vitamin D doesn’t work due to inability to link to receptors at the cellular level] have significant gonadal insufficiency, decreased sperm count and motility, and histological abnormalities of testis, ovary and uterus.” They also point out that vitamin D is involved in female reproduction—including IVF outcome, so it is a bit surprising that the article in the Daily Mail gave the impression that the research by Vandekerckhove was a totally new concept.
The review also stated that in men, higher vitamin D levels are positively associated with semen quality and androgen (male hormone) status, and that vitamin D treatment might increase testosterone levels.
One thing that is missing in these excellent studies is any discussion of the production of nitric oxide (NO) by sunlight exposure. NO is a potent vasodilator that is essential for proper erection in men, meaning it relaxes the blood vessels, allowing the blood to pass more easily through the vessels. Without it erectile dysfunction (ED) occurs. Viagra, Cialis and other such ED drugs work through a Nitric Oxide pathway and act by keeping NO in circulation for a longer period. But they don’t work in about one-third of the cases, and the effect diminishes over time, not to mention the side effects such as headaches, body aches and pains, gastrointestinal distress, dizziness, vision changes, flushing, congestion and runny nose. Since sunlight exposure increases NO, it is probably a better choice. For those who wish to produce a pregnancy, ED could be a devastating problem, and sunlight may be the answer.
Sunlight exposure has so many positive properties that we may never know them all. Use non-burning sunlight safely. Here’s to a successful pregnancy and a sunny family life!
Vandekerckhove, F. Presentation at the European Society of Human Reproduction and Embryology (ESHRE) annual conference in Lisbon, Portugal, from June 14 to 17.
 Lerchbaum E1, Obermayer-Pietsch B. Vitamin D and fertility: a systematic review. Eur J Endocrinol. 2012 May;166(5):765-7.
 Burnett AL. The role of nitric oxide in erectile dysfunction: implications for medical therapy. J Clin Hypertens (Greenwich). 2006 Dec;8(12 Suppl 4):53-62.
By Marc Sorenson, EdD. Sunlight Institute
There are few things that improve our wellbeing like arising early in the morning and walking outside on a bright, sunny day. Our attitude improves, our serotonin and endorphin levels increase and there is an almost immediate feeling of exhilaration. We also become less confrontational, and our minds seem to click on all cylinders. Later on, around midday, if we are fortunate enough to have time to safely sunbathe (with lots of skin exposed), we produce large quantities of vitamin D, and our nitric oxide levels increase. This gives us a delicious feeling of relaxation and an almost instantaneous lowering of blood pressure as the cares of the day melt away.