By Marc Sorenson, EdD… Sun exposure benefits…
A very important paper regarding the necessity for sun exposure has recently been published by the journal Medical Hypothesis.[1] It is entitled Regular sun exposure benefits health, and it discusses the pros and cons of sun exposure. One of the salient statements in the paper is that intermittent sun exposure may increase the risk of skin cancer, whereas regular exposure to sunlight might benefit health. For those of us who have for years studied the beneficial effects of sun exposure, the use of the word “might” is the only drawback to the statement. There is no doubt that for the majority of the population, regular sun exposure absolutely protects and enhances health.
Among the diseases mentioned as being reduced or prevented by regular sun exposure are the following:
- Cancers: Colon, breast, prostate and non-Hodgkin lymphoma
- Multiple sclerosis
- Hypertension
- Diabetes
As the authors mention, most of these positive effects of sun exposure were previously ascribed to Vitamin D, but they point out that immune system function is enhanced by sun exposure beyond the effects of vitamin D, and list other non-vitamin D benefits of the sun, including:
- Production of nitric oxide
- Production of melatonin
- Production of serotonin
- Regulation of the circadian clock
I have discussed most of these items on the Sunlight Institute web site, but it was good to see new research that, in particular, separated the health benefits of sun exposure from vitamin D production. The idea that has become popularized during the past decade, that all benefits of sun exposure come from increased vitamin D production, is simply not true and can lead to the supplementation of vitamin D as a “cure” for diseases that may not be influenced by that hormone.
Of course, vitamin D is an exceptionally important photoproduct, and the only natural way to attain it is by exposure to the sun or to other sources of UVB light (such as a sunlamp or a tanning bed). The beauty of using these sources, rather than a vitamin-D capsule, is that all of the benefits of nitric oxide, melatonin, serotonin and circadian entrainment are included in the package.
Safely enjoy the sun, and you then will also safely enjoy better health. Remember not to burn, and to gradually develop a good tan.
[1] van der Rhee H, de Vries, E, Coebergh, J. Regular sun exposure benefits health. Medical Hypotheses 97 (2016) 34–37
Sun Exposure by Marc Sorenson, EdD, Sunlight Institute…
A recent study from Canada produced some intriguing information regarding the influence sun exposure may have on prostate cancer (PC). A total of 1,638 men with prostate cancer and 1,697 without, were assessed between 1994 and 1997 to determine the amount of time each spent outdoors exposed to ultraviolet light (UV).[1] The men were a mixture of Indians, Asians, and Caucasians.
The men were assessed for their sun habits by determining how many hours per day they spent in the sun, whether sun exposure was moderate (2-6 hours per day) or high (>6 hours per day). Interestingly, men who were in the highest level of sun exposure had a reduced risk of PC of about 32% compared to unexposed men (the control group). There was no difference when moderate levels of sun exposure were compared to risk of PC. This would indicate that more sun is better, at least in this single study
The men who were of Asian and Indian descent started out with a profoundly reduced risk of PC, having only a 17% risk or 25% risk of PC, respectively. I opine that because those two ethnic groups consume much higher levels of vegetation than Caucasians, they are more protected.
There are probably 20 studies that show a protective effect of sun exposure on PC. Early research by Dr. Esther John and here colleagues is only one of many that reported a dramatic protective influence of sun exposure on prostate cancer. They compared the lifetime sun exposure of 450 white men with advanced prostate cancer to that of 455 white men who did not have cancer.[2] The men were divided into quintiles (fifths) according to the amount of exposure they had received. Subjects in the highest fifth of sun exposure had only 51% of the risk of prostate cancer as did those in the lowest quintile.
So, most research shows an impressive association between higher sun exposure and lower risk of prostate cancer. Men, remember to be safe as you soak up that glorious sun. Don’t burn, and be sure to develop a good tan if you can. If you don’t tan, then a very short time in the sun is sufficient, after which you should wear a big hat and long-sleeved shirt. And please don’t use cancer-causing sunscreens.
[1] Peters CE, Demers PA, Kalia S, Hystad P, Villeneuve PJ, Nicol AM, Kreiger N, Koehoorn MW. Occupational exposure to solar ultraviolet radiation and the risk of prostate cancer. Occup Environ Med. 2016 Jul 27. [Epub ahead of print]
[2] John EM, Schwartz GG, Koo J, Van Den Berg D, Ingles SA. Sun exposure, vitamin D receptor gene polymorphisms, and risk of advanced prostate cancer. Cancer Res 2005;65(12):5470-79.
By Marc Sorenson, EdD. Sunlight Institute.
Regular sun exposure is one of the best ways to reduce the risk of many cancers. Although the relationship of sun exposure (and vitamin D) to the risk of prostate cancer is controversial, a study from Australia, published in 2011, showed that the less sun exposure, the greater the risk of the cancer.[1] The researchers investigated the relationship between prostate cancer incidence and solar radiation in non-urban Australia and found an inverse association. There are many other studies that indicate a protective effect of sun exposure. One of the earliest was conducted by Dr. Esther John and her colleagues: they compared the lifetime sun exposure of 450 white men with advanced prostate cancer to that of 455 white men who did not have cancer.[2] The men were divided into quintiles according to the amount of exposure they had received. Subjects in the highest fifth of sun exposure had only 51% of the risk of prostate cancer as did those in the lowest quintile.
Another study on cancer that corroborated these observations was entitled: Is prevention of cancer by sun Exposure more than just the effect of vitamin D? A systematic review of epidemiological studies.[3] In their review, the authors noted that regular sun exposure correlated to a reduced risk of colorectal cancer, prostate cancer, breast cancer and non-Hodgkin’s lymphoma (NHL). However, vitamin D levels correlated to a reduced risk of colorectal, and to a lesser extent, breast cancer, but were not correlated to a significant risk reduction in prostate cancer and non-Hodgkin’s lymphoma. The authors concluded with this statement: “Particularly in prostate cancer and NHL, other sun-potentiated and vitamin D-independent pathways, such as modulation of the immune system and the circadian rhythm, and the degradation of folic acid, might play a role in reduced cancer risk as well.” These researchers did well to remind us, that as important as vitamin D is to the human body, other effects of sun exposure may be more important in some diseases. The authors could have also mentioned the effect of sun on vasodilation, mediated by the production of nitric oxide (produced by the skin after sun exposure). They could also have discussed the influence of sun on production of serotonin and endorphins, all of which may have contributed to their observations.
Other research used childhood sunburn as a measure of UVR exposure and determined that men who had sunburned as children had only about one-fifth the risk of contracting prostate cancer as those who had not sunburned.[4] A note of caution! We are not recommending that anyone sunburn in order to prevent prostate or other types of cancer. Sunburn was used in this research to predict higher vitamin D levels, but it is not necessary to achieve those levels, since non-burning sun exposure achieves the same results. This research also demonstrated that men with lowest level of UVR exposure had more than triple the risk of prostate cancer and that onset of the disease was delayed more than four years in those who had the greatest exposure compared to those who had the least exposure. A follow-up to this study, reported that men in the lowest quartile of sunbathing were linked to a 5.33-fold greater risk of prostate cancer than those in the highest quartile. Still other research has indicated that “higher levels of cumulative exposure, adult sunbathing, childhood sunburn and regular holidays in hot climates were each independently and significantly associated with a reduced risk of this [prostate] cancer.[5]
So men, protect your prostate by regular, non-burning sun exposure. Don’t let the Powers of Darkness frighten you away from the sun.
[1] Loke TW, Seyfi D, Khadra M. Prostate cancer incidence in Australia correlates inversely with solar radiation. BJU Int. 2012 Apr;109 Suppl 3:75.
[2] John EM, Schwartz GG, Koo J, Van Den Berg D, Ingles SA. Sun exposure, vitamin D receptor gene polymorphisms, and risk of advanced prostate cancer. Cancer Res 2005;65(12):5470-79.
[3] van der Rhee H, Coebergh JW, de Vries E. Is prevention of cancer by sun exposure more than just the effect of vitamin D? A systematic review of epidemiological studies. Eur J Cancer. 2013 Apr;49(6):1422-36.
[4] Moon SJ, Fryer AA, Strange RC. Ultraviolet radiation: effects on risks of prostate cancer and other internal cancers. Mutat Res 2005;571(1-2):207-19.
[5] Bodiwala D, Luscombe CJ, Liu S, Saxby M, French M, Jones PW, Fryer AA, Strange RC.. Prostate cancer risk and exposure to ultraviolet radiation: further support for the protective effect of sun. Cancer Lett 2003;192:145-49.
By Marc Sorenson, EdD, Sunlight Institute…
A short time ago, we posted a blog showing that little boys who had high sunlight exposure were about 82% less likely to develop prostate cancer than those who were not exposed. Now let’s take a look at additional interesting science on sunlight and prostate cancer.
Norwegian research has also demonstrated an inverse correlation between prostate cancer and sunlight when death rates from prostate, breast and colon cancer were compared to the season in which the cancer was diagnosed.[i] [ii] Over 36 months, study subjects diagnosed during summer and fall (times of the greatest sunlight exposure and vitamin D production) had much lower death rates than those diagnosed in winter and spring.
Another indication of the influence of sunlight on prostate cancer is research on prostate specific antigen (PSA). The higher the PSA level in the blood, the greater is the chance of cancer. When the prostate gland is undergoing changes that may lead to cancer, PSA levels generally rise. Men with the lowest levels of lifetime sunlight exposure have higher PSA levels than those with the highest levels of sunlight exposure.[iii]
Nevertheless, a recent meta-analysis of studies of serum vitamin D levels and prostate cancer showed no relationship between prostate cancer and vitamin D.[iv] The reason for the discrepancy between a lowered risk of prostate cancer correlating to higher sunlight exposure but not correlating to a higher serum level of vitamin D is unknown. It is probable that the beneficial influence of sunlight on prostate cancer goes beyond its stimulation of vitamin D production in skin. And according to Dr. Cannell, the reason for the lack of a relationship between blood levels of vitamin D and prostate cancer may be because the subjects in the studies received much of their vitamin D from cod-liver oil, high in vitamin A, which has been shown to thwart the beneficial effect of vitamin D on cancer,[v] possibly due to the fact that retinol (vitamin A) competes with activated vitamin D for receptor sites.[vi] Suffice it to say that sun exposure is the safest and surest way to reduce the risk of prostate cancer. Men, protect your health and your love-life by getting your share of the wonderful sun.
[i] Robsahm TE, Tretli S, Dahlback A, Moan J. Vitamin D3 from sunlight may improve the prognosis of breast-, colon- and prostate cancer (Norway). Cancer Causes Control 2004;15:149-58.
[ii] Lagunova Z, Porojnicu AC, Dahlback A, Berg JP, Beer TM, Moan J. Prostate cancer survival is dependent on season of diagnosis. Prostate 2007;67(12):1362-70.
[iii] Weinrich S, Elliaon, E, Weinrich, M, Ross, K, Reis-Starr, C. Low sun exposure and elevated serum prostate specific antigen in African American and Caucasian men. AM J Health Stud 2001;17:148-55
[iv] Lu Yin, Elke Raum, Ulrike Haug, Volker Arndt, Hermann Brenner. Meta-analysis of longitudinal studies: Serum vitamin D and prostate cancer risk. Cancer Epidemiology 2009;33: 435–45.
[v] Cannell, J. Vitamin D newsletter: February 28, 2010.
[vi] Bao Y, Ng K, Wolpin BM, Michaud DS, Giovannucci E, Fuchs CS. Predicted vitamin D status and pancreatic cancer risk in two prospective cohort studies. Br J Cancer 2010;102(9):1422-7.
By Marc Sorenson, EdD, Sunlight Institute
Sunlight exposure is said to cause melanoma, which is false, as we have said many times in this blog. However, other cancers are seldom mentioned by those who would frighten us away from the sun, because the facts don’t fit their agenda. Most major cancers are profoundly reduced by sunlight. Let’s first take the example of prostate cancer (PC) risk, which has been known for at least 15 years to be associated with low sunlight exposure.
Researchers reporting their findings in the British medical journal, Lancet, compared sunlight-exposure history to the risk of contracting the disease, and they found that children who sunburned had about an 82% reduced risk of contracting PC as adults.[1] Of course, no one is recommending sunburn as a preventive measure against prostate cancer. In this case, sunburn served as a surrogate measure for a lot of sunlight exposure. Other measures of sunlight exposure similarly showed protective effects. Regular holidays in warm areas were associated with a 51% reduced risk; a high sunbathing score was associated to a 17% reduced risk, and very low sunlight exposure was associated to a tripling of risk. The researchers stated the following: “These findings are compatible with UVR having a protective role against prostate cancer.”
So why do the anti-sun groups such as the American Academy of Dermatology and the Skin Cancer Foundation mention only skin cancer and neglect to give life-saving information regarding other cancers such as PC? That is an easy answer. Both organizations make big dollars by keeping us in the dark. Follow the money to the sunscreen manufacturers, who have a cozy financial relationship with these supposedly “clean” cancer organizations.
So men, safely sunbathe and get outdoors as much as possible. Your prostate will love you for it.
[1] Luscombe CJ, Fryer AA, French ME, Liu S, Saxby MF, Jones PW, Strange RC. Exposure to ultraviolet radiation: association with susceptibility and age at presentation with prostate cancer. Lancet. 2001 Aug 25;358(9282):641-2.
By: Marc Sorenson, Sunlight Institute–
I have previously written that sunlight exposure correlates to a profoundly reduced risk of prostate cancer (PC). I also and noted that that sunlight exposure per se appeared to be much more important in reducing that cancer than was vitamin D. In fact, some vitamin D studies showed only weak correlations between vitamin D and a reduction in cancer, and the highest levels of serum vitamin D showed a J-shaped curve, meaning that the highest D levels actually correlated to a slightly increased risk. No such increase has been shown with the highest levels of sunlight exposure–quite the opposite. The highest levels of sunlight correlated to the highest levels of protection against PC.
This would indicate that sunlight has protective effects beyond the production of vitamin D. Such effects may be due to the production of serotonin, endorphins and nitric oxide, substances other than vitamin D that are produced by the skin in response to sunlight.
It was with interest, therefore, that I read a recent article describing the effect of sunlight on PC, called “Sunlight could decrease prostate cancer risk.” After reading that sunlight exposure could reduce the risk of PC by 50%, the author unfortunately stated that “this does not mean that men should deliberately sunbathe to reduce their risk of prostate cancer. Outdoor exercise and an adequate amount of vitamin D from diet should be sufficient to afford protection from the disease.” This is not a statement based on science.
The author assumed, of course, that it was vitamin D that caused the correlation of sunlight exposure to reduced risk of PC—a conclusion that may be wholly in error. What we can glean from the research is only that Sunlight exposure correlates to reduced risk of PC. There is no proof whatsoever that the correlation was caused by vitamin D, which is only one of several metabolites produced in the body after stimulation by sunlight.
I have not as yet been able to find the original research on which the article was based and cannot provide a reference at this time. However, you can read the article by going to: http://www.newsfix.ca/2013/05/06/sunlight-could-decrease-prostate-cancer-risk/.