Benefits of sun exposure by Marc Sorenson, EdD.
A new study on nutrition and skin aging corroborates what I have said previously in this blog: Sunlight is not the guilty party when skin problems occur; it is only one of many factors that influence the skin, and in some cases the influence is protective. And of course, sun exposure influence on the other organs of the body is overwhelmingly healthful.
To the extent that sun causes skin damage, it does so due to lack of proper nutrients in the diet, and there is little doubt that there will be some damage caused by sun exposure without proper nutrition. We eat too many toxic fats, too much meat and cheese, too much sugar and too many refined carbohydrates. At the same time we eat far too few vegetables and fruits, which can protect all the tissues in the body, including skin. Much of that protection is due to the high antioxidant levels of fruits and veggies. It is normal for humans to be exposed to sunlight, and it is equally normal for humans to take in the nutrients necessary to prevent skin damage, so that the sun may heal the body without harming our largest organ.
One of those antioxidants is astaxanthin, a new “superstar” in the antioxidant field. A new study shows that a group of mice that were exposed to Ultraviolet A Light (UVA,) lost water in the skin and developed wrinkles (both signs of skin aging). But in a group of mice that were also exposed to UVA and were supplemented with astaxanthin, no such skin aging occurred. This information demonstrates that poor nutritional habits may make sun exposure dangerous to the skin, because it is working without God’s natural balancing through nutrition. Our atrocious eating (and drinking) habits lead to skin damage, and sun exposure gets the blame.
Fruits and vegetable consumption help protect the skin, but other nutritional factors damage the skin. Alcohol consumption is one such factor; in one investigation, those persons who were in the highest quintile (fifth) of alcohol consumption were shown to have a 65% increased risk of melanoma.  Another indicated a 250% increased melanoma risk among those who consumed two or more alcoholic drinks per day, and a third demonstrated that those persons who consumed seven or more drinks per week had 64% greater risk of melanoma and a 23% greater risk of non-melanoma skin cancer when compared to non-drinkers. There are at least two other negative dietary habits that correlate to increased skin-cancer risk: first, the highest dairy-product consumption has also been shown to correlate to a 2½ times increased in risk of developing a non-melanoma carcinoma (common skin cancer). Secondly, the types of fats we consume are exceptionally important. Fats we consume in junk foods are deadly, both for overall health and for skin cancer. They are filled with free-radical molecules that wreak havoc on the skin; if we eat such fats without massive quantities of colorful fruits and veggies, we will be much more susceptible to skin damage and potential cancers of all kinds.
Sun exposure is absolutely essential for human health; but to protect yourself against any damage to the skin, eat the foods that were made for humans!
 Komatsu T, Sasaki S, Manabe Y, Hirata T, Sugawara T. Preventive effect of dietary astaxanthin on UVA-induced skin photoaging in hairless mice. PLoS One. 2017 Feb 7;12(2):e0171178.
 Millen AE, Tucker MA, Hartge P, Halpern A, Elder DE, Guerry D 4th, Holly EA, Sagebiel RW, Potischman N. Diet and melanoma in a case-control study. Cancer Epidemiol Biomarkers Prev. 2004 Jun;13(6):1042-51.
Bain C, Green A, Siskind V, Alexander J, Harvey P. Diet and melanoma. An exploratory case-control study. Ann Epidemiol 1993;3:235-38.
Jessica T. Kubo, Michael T. Henderson, Manisha Desai, Jean Wactawski-Wende, Marcia L. Stefanick, Jean Y. Tang. Alcohol consumption and risk of melanoma and non-melanoma skin cancer in the Women’s Health Initiative. Cancer Causes Control. 2014 Jan;25(1):1-10.
Hughes MC, van der Pols JC, Marks GC, Green AC. Food intake and risk of squamous cell carcinoma of the skin in a community: The Nambour skin cancer cohort study. Int J Cancer 2006; online publication ahead of print.
Despite the fact that higher vitamin D levels are nearly always found to be related to reduced risk of cardiovascular disease and associated diseases such as diabetes mellitus, randomized controlled trials have not found that vitamin D supplementation reduces risk of cardiovascular disease.
Therefore, vitamin D levels are likely a surrogate measurement for sun exposure, meaning that some other photoproduct such as nitric oxide (NO) may be responsible for the lowered risk of CVD. A pair of recent papers reported that leisure-time or recreational outdoor physical activity was significantly associated with reduced risk of cardiovascular disease. In a study in the U.S., both frequency and intensity of outdoor activities were associated with reduced risk, as was higher vitamin D level. When vitamin D levels were removed from the equation, an inverse association was still found between outdoor recreational activity and mortality. The authors stated the following: “The underlying mechanism for this association may not involve 25(OH)D hence, further studies are warranted to confirm and investigate the underlying mechanism.” I would suggest that nitric oxide was the protective photoproduct, produced by sun exposure, which lessened the risk of CVD with outdoor activity.
Similar findings have been found for hypertension, diabetes mellitus, heart failure, stroke, and myocardial infarction (heart attack). In a study in Finland, older adults who had moderate leisure-time activity had 30-40% reduced mortality and cardiovascular disease rates than those with low activity levels, while those with high activity levels had 50% lower rates.
Two messages from this research: (1) Start living more of your life outdoors. (2) Be sure to obtain plenty of non-burning sun exposure during you outdoor activity. Your life may depend on it.
 Wang L, Song Y, Manson JE, Pilz S, März W, Michaëlsson K, Lundqvist A, Jassal SK, Barrett-Connor E, Zhang C, Eaton CB, May HT, Anderson JL, Sesso HD. Circulating 25-hydroxy-vitamin D and risk of cardiovascular disease: A meta-analysis of prospective studies. Circ Cardiovasc Qual Outcomes. 2012 Nov 1;5(6):819-29.
 Song Y, Wang L, Pittas AG, Del Gobbo LC, Zhang C, Manson JE, Hu FB. Blood 25-hydroxy vitamin D levels and incident type 2 diabetes: a meta-analysis of prospective studies. Diabetes Care. 2013 May;36(5):1422-8.
 Veloudi P, Jones G, Sharman JE. Effectiveness of vitamin D supplementation for cardiovascular health outcomes. Pulse 2016;4:193-207 https://www.karger.com/Article/FullText/452742
 Donneyong MM, Taylor KC, Kerber RA, Hornung CA, Scragg R. Is outdoor recreational activity an independent predictor of cardiovascular disease mortality – NHANES III? Nutr Metab Cardiovasc Dis. 2016 Aug;26(8):735-42.
 Barengo NC, Antikainen R, Borodulin K, Harald K, Jousilahti P. Leisure-Time Physical Activity Reduces Total and Cardiovascular Mortality and Cardiovascular Disease Incidence in Older Adults. J Am Geriatr Soc. 2016 Dec 26. doi: 10.1111/jgs.14694. [Epub ahead of print]
For those who follow my writings, it should now be obvious that the risk of melanoma is decreased by regular sun exposure, and that the evidence for the health benefits of safe sun becomes clearer by the day. I opine that millions of lives could be saved yearly by regular, non-burning sun exposure for the entire population.
Another benefit of moderate sun exposure, or other ultraviolet radiation (UVR), is that it does not cause sufficient DNA damage to prevent efficient repair. A study published in the British Journal of Dermatology reviewed the impact of repeated low level sunlight exposures on vitamin D status and DNA damage/repair in light and brown skinned individuals. The UVR doses were equivalent to 13-17 minutes of midday exposure in the UK. The study reported that no evidence existed for these low-level exposures leading to accumulated DNA-damage, indicating that any damage was quickly repaired. The research also showed that the exposures led to sufficient vitamin D levels in the participants. In addition, it has been shown that “Regular exposure to UV leads to an almost complete disappearance of DNA damage in the basal and suprabasal layers of the epidermis, where the initiating of skin cancer occurs. It is no wonder that regular sun exposure is associated with less melanoma! Soak up some moderate, non-burning sun!
 Felton SJ, Cooke MS, Kift R, Berry JL, Webb AR, Lam PMW, de Gruijl FR, Vail A, and Rhodes LE. Concurrent beneficial (vitamin D production) and hazardous (cutaneous DNA damage) impact of repeated low-level summer sunlight exposures. Br J Dermatol. 2016 Jul 14. doi: 10.1111/bjd.14863. [Epub ahead of print]
 van der Rhee H, de Vries E, Coomans C, van de Velde P, Jan Willem Coebergh JW. Sunlight: For Better or For Worse? A Review of Positive and Negative Effects of Sun Exposure. Cancer Research Frontiers. 2016 May; 2(2): 156-183.
Almost no one realizes the dramatic improvement that sun exposure can make on athletic performance. Years ago I helped Dr. John Cannell obtain translations of many esoteric and decades-old studies that had been forgotten, probably due to the fact that sun lamps were used to create some of the improvements in athletics, and have fallen out of favor due to the sunscare movement. I co-authored a paper with Cannell, called Athletic Performance and Vitamin D. That paper is the source of much of the material covered here, and it demonstrates the remarkable, positive effect of sun or other ultraviolet (UV) exposure on human performance. I would also strongly suggest that the readers avail themselves of Dr. Cannell’s book on the subject, called The Athlete’s Edge, which discusses in far greater detail the materials introduced here.
One of the salient studies on UV exposure took place in 1957 and assessed the influence of sun exposure on strength and performance over a two-year period. During that time six subjects were able to increase athletic performance and muscle trainability through systematic UV exposure. But when vitamin D3 was used, it not only did not work, it inhibited the performance-enhancing effect of the UV. I sometimes fear the public is beginning to believe that if sun exposure is proven to enhance human health, one needs only to take a vitamin D pill. Don’t get pulled into that idea. Sun exposure will always be more important than any of the photoproducts whose production it stimulates.
Here are some of the other salient studies on sun exposure and performance. In 1938, Russian researchers demonstrated that a series of four UV treatments improved speed in the 100-meter dash compared to four non-irradiated students, when both groups were undergoing daily physical training. The times improved from 13.51 seconds to 13.28 seconds in the non-irradiated group and from 13.63 to 12.62 seconds in the irradiated group. In other words, the UV-treated group improved by three-fourths of a second more than the non-UV group. That may seem like a relatively small improvement, but three-fourths of a second better time in a 100-meter dash could be the difference between first and last place!
German research from 1944 showed that the exposure of 32 medical students to UV, twice weekly during for six weeks, associated with a 13% improvement in endurance, whereas performance of a control group was unchanged.
Other German research shows that the ability of a muscle to gain strength (trainability) is much better in summer than winter, and peaks in September. In fact, the trainability in September was 2½ times higher than the average monthly trainability for the entire year.
So you who love athletics, don’t avoid the sun. It may make you a winner. But don’t burn.
When we consider reaction time, muscle and bone strength, speed and endurance, we should realize that these measurements are not only important for athletes; they are important for all aspects of living for all people. Everyone wants to be stronger, quicker, and faster, as well as have more endurance in daily activities. So embrace the sun, but do it safely and don’t burn.
 Cannell JJ, Hollis BW, Sorenson MB, Taft TN, Anderson JJ. Athletic performance and vitamin D. Med Sci Sports Exerc. 2009 May;41(5):1102-10.
 E. Seidl and Th. Hettinger. The Effect of Vitamin D3 on the Strength and Performance of a Healthy Adult. International Journal Physiology, including Industrial Physiology, Vol. 16, Pages 365-372 (1957).
 Gorkin Z, Gorkin MJ, Teslenko NE. [The effect of ultraviolet irradiation upon training for 100m sprint.] Fiziol Zh USSR. 1938;25:695-701.
 Lehmann G, Mueller EA. [Ultraviolet irradiation and altitude fitness.] Luftfahrtmedizin. 1944;9:37-43. [Article in German].
 Hettinger T, Muller EA. Seasonal course of trainability of musculature. Int Z Angew Physiol. 1956;16(2):90-4.
 Sigmund, R. The effect of ultra-violet rays on the human reaction time. Strahlentherapie. 1956;101(4):623-9.
 Seidl E. [The effect of ultraviolet irradiation on reaction time.] Int Z Angew Physiol. 1958;17(4):333-40.
Research shows that sunlight boosts the effectiveness of T-cells, an integral part of the immune system. T-cells are a type of lymphocyte that recognizes and binds to foreign invaders, thereby rendering them harmless. This is an important new finding, which demonstrates another beneficial effect of sun—one that has no relationship to vitamin D.
The key player in this action is the blue-light spectrum of sunlight that stimulates hydrogen peroxide production. The hydrogen peroxide (HP) causes T-cells to move to the site of infection, and it (HP) is also involved in the killing of noxious bacteria. Dr. Gerard Ahern, one of the primary investigators, stated it in this way: “T cells, whether they are helper or killer, need to move to do their work, which is to get to the site of an infection and orchestrate a response. This study shows that sunlight directly activates key immune cells by increasing their movement.”
Also interesting is the fact that the skin has a large share of the total T-cells in humans, about twice the number circulating in the blood. Think about this magnificent body of ours! It is programmed to immediately respond to any invasions that may occur in the skin, and sun exposure, if we take full advantage of it, immediately accelerates the process. Then, when the t-cells are activated by the blue light, they can move rapidly to other body areas where they can be utilized.
Sun exposure has also been found to have an exceptionally important and positive effect on autoimmune diseases such as lupus, MS, rheumatoid arthritis and others, many of which have been found to associate with low solar radiation and vitamin D. In this case, a different type of T-cell, called a regulatory T-cell, attacks the body’s own tissue, mistaking it for a foreign invader, and causes severe damage. The mechanism of autoimmune disease prevention by sunlight may be the suppression of regulatory T cells, in a manner that impedes the immune system’s attacks on its own tissues. 
Sunlight is one of God’s (or Nature’s) greatest miracles. Be sure to receive your full contingent of wonderful, non-burning sun.
 Thieu X. Phan, Barbara Jaruga, Sandeep C. Pingle, Bidhan C. Bandyopadhyay, Gerard P. Ahern. Intrinsic Photosensitivity Enhances Motility of T Lymphocytes. Scientific Reports, 2016;6:39479
 Schwalfenberg GK. Solar radiation and vitamin D: mitigating environmental factors in autoimmune disease. J Environ Public Health. 2012;2012:619381.
ArtukovićM1, Ikić M, Kustelega J, Artuković IN, Kaliterna DM. Influence of UV radiation on immunological system and occurrence of autoimmune diseases. Coll Antropol. 2010 Apr;34 Suppl 2:175-8.
Marsh-Wakefield F, Byrne SN. Photoimmunology and Multiple Sclerosis. Curr Top Behav Neurosci. 2015;26:117-41.
Sun exposure and tanning-bed exposure have been much maligned by those who would increase sunscreen sales and other “protection” against melanoma. But, in 2016, a paper was written regarding the truth about tanning beds. According to this paper, Risk of melanoma with tanning beds is slightly associated with home use, but there is no significant increase in risk with beds used in tanning salons. This is according to a soon-to-be-published analysis of studies that differentiated between home-use tanning beds and salon use of tanning beds.
The analysis showed that when all tanning devices were considered together, tanning bed use was associated with a 15%-20% increased risk of melanoma. However, when home-use tanning was separated from salon use, salon use showed only a 5% increased risk, which was not significant. In other words, there may have been no risk whatever. In fact, in three of the studies that were part of the analysis, overall use of tanning beds associated to a lessened risk of melanoma.
Therefore, if there is any increased risk of melanoma with tanning-bed use, it is all due to the use of home units. This is what we might expect, since salons take care to assess skin type and monitor the time spent in the unit.
Before we decide to eschew the use of home units, however, we should also take into consideration the very healthful benefits of tanning-bed use in general. Here are a few well-documented facts about the benefits:
- Tanning bed use is associated with a reduced risk of clots.
- Tanning-bed use is associated with increased vitamin D levels.
- Tanning-bed use is associated with stronger bones.
- Tanning-bed use can cure psoriasis and eczema and tanning beds are often recommended by dermatologists.
- Tanning-bed use more than three times yearly is associated with a 40-50% reduced risk of endometrial cancer.
- Tanning-bed use is associated to lower breast-cancer risk.
- A 20- year study demonstrated that both sun exposure and tanning-bed exposure reduced the risk of death; women who used tanning beds were 23% less likely to die of any cause than women who did not use them.
The key to safe tanning-bed use is the same key as for safe sun exposure: Don’t be taken in by the anti-sun, anti-tanning movement.
 Hoel, D. Commercial Tanning Salons and Melanoma Risk. Letter to the editor, Dermato-endocrinology. Not yet published.
 Lindqvist PG, Epstein E, Olsson H. Does an active sun exposure habit lower the risk of venous thrombotic events? A D-lightful hypothesis. J Thromb Haemost. 2009 Apr; 7(4):605-10.
 Holick, M. Boston University. “Effects Of Vitamin D And Skin’s Physiology Examined.” Science Daily 21 February 2008 <http://www.sciencedaily.com¬ /releases/2008/02/080220161707.htm>.
 Tangpricha V, Turner A, Spina C, Decastro S, Chen TC, Holick MF. Tanning is associated with optimal vitamin D status (serum 25-hydroxyvitamin D concentration) and higher bone mineral density. Am J Clin Nutr 2004;80:1645-49.
 Radack KP, Farhangian ME, Anderson KL, Feldman SR. A review of the use of tanning beds as a dermatological treatment. Dermatol Ther (Heidelb). 2015 Mar;5(1):37-51.
 Epstein E, Lindqvist PG, Geppert B, Olsson H. A population-based cohort study on sun habits and endometrial cancer. Br J Cancer. 2009 Aug 4;101(3):537-40.
 Yang L, Veierød MB, Löf M, Sandin S, Adami HO, Weiderpass E. Prospective study of UV exposure and cancer incidence among Swedish women. J Intern Med. 2014 Jul;276(1):77-86
 Lindqvist PG, Epstein E, Landin-Olsson M, Ingvar C, Nielsen K, Stenbeck M, Olsson H. Avoidance of sun exposure is a risk factor for all-cause mortality: results from the Melanoma in Southern Sweden cohort. J Intern Med. 2014 Jul;276(1):77-86.
Many years ago, I read of ongoing research by Dr. Pelle Lindqvist—reasearch indicating that greater exposure to sunlight resulted in longer life. I made several attempts to contact Dr. Lindqvist, but was unsuccessful. However, one of his colleagues answered my query and informed me that the research would not be completed later on and then be published. The results are now available, and they are impressive.
During a 20-year period, the subjects in the study who avoided sun exposure were twice as likely to die of any cause compared to those who had the highest sun exposure, and the researchers made this statement: “In both models the summary sun exposure variables showed a ‘dose-dependent’ inverse relation between sun exposure and all-cause death.”
Is sunlight the best disinfectant? Through serendipity, I happened on an article called Natural Alternatives to Bleach for Disinfecting. It discussed pros and cons of such disinfectants as bleach, vinegar, hydrogen peroxide and yes, sunlight. The article stated that bleach could be dangerous, causing irritation to the eyes, mouth, lungs and skin, and when mixed with ammonia could result in the release of toxic fumes.
The authors suggested three alternatives: vinegar, which is non-toxic, hydrogen peroxide, which can cause burns at high concentrations, but when used safely is reasonably safe, and sunlight, which like vinegar is nontoxic. The article states “In fact, scientists have found that exposing a bottle of water to sunlight for 6 hours is an economical way to provide developing countries with safe drinking water (see References 2). The disinfecting properties of sunlight can also be useful around the house. If you have an object that you can move outside, the sun’s rays can help disinfect it. A stained piece of white laundry can be effectively brightened and disinfected by spraying the stain with lemon juice or vinegar and then hanging it in the sun.”
Imagine that—no wonder my mother hung her clothes out on a line in the summer sun to dry, although I don’t recall any use of vinegar or lemon juice.
The mention of water also took me back a few years to the time I spent a week with a Mexican friend of mine in a small town near Guadalajara called Juchipila. As most of you know, the drinking water in Mexico is often contaminated with noxious bacteria, and the sale of bottled water to prevent “Montezuma’s revenge” is big business. While there, my friend Miguel and I visited a bottled-water plant. Interestingly, the only method of purification was the exposure of the water to ultraviolet light. It obviously did a terrific job, because the proprietor did a good business with no reported problems of related bacterial diseases.
There was a time when sunlight was used to disinfect hospitals, and such should be the case now, considering the superbugs that have developed a resistance to antibiotics. The legendary humanitarian Florence Nightingale observed that sunlight helped heal wounded soldiers and insisted that hospitals be constructed to allow the free entry of sunlight.
In reality, it has long been known that sunlight is a powerful disinfectant and bactericide. As early as 1877, researchers discovered that sugar water left in the shade became cloudy, indicative of bacterial growth, but if exposed to sunlight, it remained clear. In 1890, the German microbiologist Robert Koch (who had isolated and described the tuberculosis bacterium in 1882), showed that sunlight killed TB bacteria. Later on, research showed sunlight also killed E. coli bacteria in twelve feet of seawater and in waste stabilization ponds.  
In the aforementioned article comparing alternative disinfectants with bleach, the authors mentioned that exposing the armpits to sunlight would kill the bacteria that caused odor. There is little that I enjoy more than sunbathing with my hands behind my head and my armpits exposed to the sun. Lots of vitamin D, nitric oxide and endorphins produced, and later on I am more popular with my friends!
Sunlight exposure has been shown to heal Tuberculosis, psoriasis and a host of other diseases. To protect against a multitude of diseases, infectious and otherwise, be sure that you and your environment are exposed to plenty of sunlight, but also be sure not to burn. Any reddening of the skin indicates that you have had enough.
 Nightingale, F. Notes on Hospitals (third edition) Longman, Roberts and Green 1863.
 Downes, A. Researches on the effect of light upon bacteria and other organisms. Proc Roy Soc Med 1877;26:488.
 Hobday, R. The Healing sun. Findhorn Press 1999:132.
 Hart, D. Sterilization of the air in the operating room by special antibacterial radiant energy. J Thorac Cardiovasc Surg 1936;6:45.
 Gameson, A. et al. Field studies on effect of daylight on mortality of coliform bacteria. Water Res 1967;1:279.70.
 Calkins, J. et al. The role of solar ultraviolet radiation in natural water purification. Photochem Photobiol 1976;24:49.
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.