Sunshine: Dangerous or Healthy?

 

By Tom Petrie, B.S., C.D.N.

 

As with so many health topics in America, the public is often misinformed. Such is the case with the "health dangers of sunshine". 

The Dangers of Sun Exposure

Currently, some 600,000 new cases of skin cancer are reported every year.(1) Over the years, there have been numerous publications making the claim that sunshine exposure increases the risk of developing skin cancer as well as hastens aging of the skin. It would seem, therefore, that "avoiding the sun" would be an obvious response to this problem. It is believed that Ultraviolet A rays are the cause of hastened aging and skin cancer while the Ultraviolet B rays are the source of sunburn. The UVB rays are also the source for making Vitamin D in the skin. Melanomas are currently the tenth most common form of cancer in the U.S.

Examples of Current and Popular Thinking on the Subject of Sunshine Dangers

"Dermatologists now consider skin cancer an epidemic in the United States. You can avoid becoming a statistic by using sunscreen and staying out of the direct sun in the heat of the day. Remember to encourage good sun habits with your children as well. Providence experts can explain how best to protect yourself and your loved ones."(2)

Doctors from the AMC Cancer Research Center in Denver, CO have been working on reducing sun exposure in school children.(3) This Denver research center argued that too few elementary schools had sun protection policies in place! Imagine that, we're not protecting our children from...the sun!

This is also what has been proposed by experts from the Centers for Disease Control in Bethesda, Maryland. (4) 

Since there is an "obvious" problem of "too much sun", we'd better protect our children's exposure to the sun, right? Not so fast! 

To prove their theory, all organizations recommending reduced sun exposure for children (American Academy of Dermatology, the CDC, etc.) ought to complete one simple step: actually measure the Vitamin D blood levels in thousands of school children across America. Vitamin D is produced in the skin from sun exposure. This has not been done by any of these groups.

Normal Sunshine is Not a Problem for Children, or Adults, for That Matter!

How come there has been little effort to protect the health of our children against problems that have exploded in recent years? We're talking, of course, about allergies, diabetes, childhood cancer, obesity, autism, and the generally miserable fitness level of our children. Where's the talk of some national policies against these problems?

With all these crucial health concerns being significantly ignored, doesn't anyone find it odd that there are folks worried about "protecting" our children from sun exposure? But, there is a danger, isn't there? After all, sun exposure does cause skin cancer, doesn't it? 

Skin Cancer

There are different types of skin cancer including basal cell carcinomas, squamous cell carcinomas and melanoma. The first two are the most common but easily treated. Melanoma, on the other hand, can metastasize to other organs and may kill relatively quickly.

As for what causes melanomas, there may be a genetic link. It appears that genetic factors such as fair skin and hair or the tendency to develop moles increases the chances of developing melanomas. According to the American Association for the Advancement of Science (meeting in PA, April, 1998), sunscreen is not believed to reduce the risk of development of melanomas. Also, a 2003 study of 966 patients that had suffered painful sunburns showed the following: lifetime sun exposure appeared to be associated with a lower risk of malignant melanoma (4). Soll-Johanning and Bach showed that sun exposure reduced the risk of melanoma. (5)

A British study in 2002 reviewed the link between malignant melanoma and sunscreen use. While acknowledging the results to be controversial, the report also stated that there is no clear link between sunscreen use and the prevention of melanoma. While two studies showed a protective effect, three showed a negative association, meaning there was more malignant melanoma with sunscreen use. (6)

Other Causes of Melanoma

It should be noted that poor diets, excessive alcohol consumption and obesity likely explain half of melanoma mortality rates in the U.S. (7) (8)  It has also been shown that occupational exposure to solar UV reduces the risk of melanoma. (4) (5)  Thus, while excess sun exposure ought to be avoided, there's little scientifically based reason to hold up the risk of melanoma as a reason to avoid sun exposure.

On the other hand, two studies cited in BBC, February 1, 2005, showed that sunshine helped to beat the potentially deadly skin cancer malignant melanoma. Patients with increased sun exposure were less likely to die than other melanoma patients. In addition, patients who had melanomas but more previous sun exposure suffered from a less aggressive tumor variety. In another study of 3,000 individuals with non-Hodgkin's Lymphoma, the risks of developing cancer were reduced 30 to 40 percent when individuals were exposed to UV rays from the sun or from sunlamps!

Dr. Bernard Ackerman, One of the Foremost Authorities on Sun Exposure and Skin Cancer

One of the foremost authorities on sun exposure and skin cancer is Dr. Bernard Ackerman, a dermatologist and the director of the Ackerman Academy of Dermatopathology (DP) in New York. DP is the study of the disease processes that affect the skin. It involves detailed knowledge of the microscopic anatomy of the skin's structure in health and disease. Ackerman is the author of over 600 research papers and has received numerous professional awards. 

On July 20, 2004 he told the New York Times that "the field is just replete with nonsense." For example, Dr. Ackerman does not believe that the link between melanoma and sun exposure (a central dogma of dermatology) has been proven. He is deeply tanned and is not afraid to expose his body to the sun. Dr. Ackerman does, however, recommend that folks avoid excessive skin exposure to avoid premature aging of the skin.

He also does not believe that sunburn, even the kind that causes blistering of the skin, necessarily leads to cancer later in life. Basically, according to Dr. Ackerman, "the research is inconsistent and fails to make the case."

Ackerman also questions whether the so-called "epidemic" of melanoma actually exists. He notes, for example, that the definition of melanoma has changed over the past few decades leading doctors to diagnose, remove and cure lesions that, until recently, would not have been called melanoma at all.

Dermatologists get much of their information from the Skin Cancer Foundation which is heavily supported by the sunscreen industry. Even their quarterly newsletter, Sun and Fun News, is funded by SCF. This is what medical writer Michael Castleman had to say about the issue, writing in Mother Jones Magazine back in 1998: "No wonder the foundation doesn't give much credence to the growing number of studies showing that even so-called broad spectrum sunscreen doesn't prevent melanoma. Like the road-destroying trucks that guaranteed work for concrete companies, rising melanoma rates scare people into using more sunscreen." Back in 1972, sales of sunscreens were around $18 million. Today they are nearly half a billion dollars!

The Positive Effects of Sunshine

Here are nine relevant points that might help you to understand the benefits of sunshine:

  1. The human race evolved under the sun for thousands of years, in harmony with its heat and light.

  2. Sunlight has been used therapeutically for thousands of years. Before antibiotics, it was even used to treat diseases like tuberculosis.

  3. Sunlight is the only reliable source of Vitamin D, and the kind most bioavailable to the human body.

  4. Vitamin D deficiency is likely a significant cause of our epidemic of osteoporosis along with insufficient exercise and insufficient intake of dark green leafy vegetables.

  5. Vitamin D can help to prevent at least 100,000 cases of cancer in the United States, including breast cancer, each year.

  6. Some 70 to 150 million Americans are likely Vitamin D deficient. Of course, this varies depending upon what laboratory standards are used. Most standards are very liberal, thus making the problem appear much less severe than it really is.

  7. Vitamin D can help reduce the risk of heart disease. (8)

  8. Vitamin D deficiency may play a key role in preventing Multiple Sclerosis.

  9. Since damage from UVA and UVB rays is dependent on insufficient "systemic oxidative repair mechanisms", one's diet and lifestyle is critical to determining what, if any, "damage" might be caused by sun exposure.

Vitamin D

Vitamin D can be made in your skin via exposure to sunlight, a fact that has been known for over fifty years. What is possibly news to many Americans is that they might be suffering from unrecognized deficiencies of this key nutrient! While it has been thought that rickets disappeared after milk was fortified with the vitamin in the early 30's, several doctors have noticed an unusual number of cases in recent years. These cases were primarily amongst breast fed babies and among African American women. Many physicians are noticing adults with severe muscle weakness and pain who are eventually diagnosed with Vitamin D deficiency! Infant formula contains Vitamin D, but breast milk contains very little, especially in women with dark skin.

It should be noted that just because someone does not have a diagnosed Vitamin D deficiency does not mean that they're optimally supplied with the nutrient. Blood levels below optimal are quite common and levels that are considered normal might well be below optimal levels.

Dr. Michael F. Holick, a Boston University scientist who is a prominent proponent of the positive role for Vitamin D in human nutrition says that it is a mistake to equate Vitamin D deficiency to only rickets. In other words, if you don't have bowed legs, you don't have to worry. "There's nothing further from the truth." Holick thinks the current recommendation should be increased from 200 to 600 I.U. per day to 1,000 I.U. per day. In his new book, The UV Advantage, he argues for modest sun exposure of the skin for 5 to 15 minutes per day. After this, he recommends that you use a sunscreen to reduce your risk of skin cancer or premature wrinkling of the skin.

Dr. Ken Cooper directs the Cooper Institute, a Dallas based nonprofit research center. He feels that since studies indicate 65 percent of Americans don't get enough Vitamin D, he says the recommended intake is too low. Because so many get so little, they're suffering an increased risk of fractures, certain cancers and diabetes.

The amount of Vitamin D made in the skin from exposure to Ultraviolet light depends on many things including: skin type; latitude -- there's less UV rays in the northern climates; altitude -- the higher up you are, the more UVB reaches you; length of exposure; how tanned you are -- the more tanned, the less Vitamin D made; use of sunscreen; how much clothes you're wearing.

Unfortunately, many adults spend too much time indoors and when they are outdoors are covered with clothes. Orthodox Jews and Muslim women are often covered from head to toe. Such folks are getting virtually NO Vitamin D from the sun and are likely deficient. Others brainwashed by the pro-sunscreen lobby cover themselves with sunscreen with any significant sun exposure. Finally, glass filters out over 95 percent of the beneficial UVB rays, so there is little made when sitting near the window in one's house or car.

So what does this mean for deficiency levels of Vitamin D? Some 40 to 80 percent of American adults are deficient in this vitamin, with African American women estimated to be at 80 percent. Much more comprehensive and consistent testing needs to be done, especially on senior citizens and others at risk of being Vitamin D deficient.

Vitamin D and Cancer Prevention

According to the Washington Post, May 21, 2004, many forms of cancer increase the farther away you get from the equator. Such cancers as breast, colon and prostate cancer appear associated with reduced blood levels of Vitamin D. This is a direct consequence of less UV exposure from natural sunlight.

The work of William B. Grant, Ph.D. here in the U.S. indicates that more than 30,000 Americans likely die from over a dozen types of internal cancers annually due to insufficient solar UVB radiation. (9) There are 13 malignancies that showed this inverse correlation, mostly reproductive and digestive cancers. The strongest inverse correlation is with breast, colon and ovarian cancer. Other cancers apparently affected by sunlight include tumors of the stomach, uterus, bladder, esophagus, and rectum. (10)

The highest rates for prostate cancer are among African Americans, followed by countries in northern Europe. Now Scandinavians and African Americans are quite different, but they are alike in this important way: both groups have very low blood levels of Vitamin D. This is because they don't get enough exposure to the sun.

Recently, The British Medical Journal wrote in an editorial that moderate sun exposure is a more prudent recommendation than to avoid all sun exposure. (11) The authors noted that sunscreens do not adequately protect against Ultraviolet A light, which is "carcinogenic" and also stated that sunscreens "should not be relied upon to prevent melanoma".

The researchers further stated that "sun exposure is the main source of Vitamin D, which reduces the risk of certain cancers." People in the United Kingdom cannot synthesize Vitamin D during the winter months due to a decreased amount of sun exposure. The authors say that people should get moderate sun exposure without sunscreen in order to allow the adequate synthesis of Vitamin D. This is exactly what Dr. Michael F. Holick has stated in his writings.

It's a very lengthy topic, but essentially, it appears that Vitamin D acts like a "brake" on cell growth, thereby preventing uncontrolled cell growth -- cancer.

As for dietary intake of Vitamin D, there is some in fortified milk and fatty fish, but most people get very little through their diets. Cod liver oil is a popular supplement providing Vitamin A and Vitamin D.

Toxicity of Vitamin D

Excessive intakes of Vitamin D, enough to cause toxicity symptoms, are exceedingly rare. This is why lifeguards and others who work long hours in the outdoors do not suffer from Vitamin D toxicity. Also, as fully explained in Barefoot's and Reich's book, The Calcium Factor, the dangers of excessive intakes of Vitamin D have always been exaggerated. The original studies on Vitamin D toxicity considered a "safe" intake to be less than 20,000 I.U. per kilogram of body weight. The toxicity that was evident upon intakes of 25,000 I.U. (62,000 times the "Daily Value, formerly the U.S. RDA of 400 I.U.), was possibly due to the binders used in the production of such pills back in the early 1930's. Even water cannot be consumed at the rate of 62,000 times the recommended dose without ill effect. Thus, water is more toxic than Vitamin D!

The lifelong claim that excessive intakes of Vitamin D are toxic is simply wrong in practical terms. Who is going to swallow 62,500 400 I.U. Vitamin D pills (or 25,000,000 1,000 I.U. pills) anyway?

Diet and Skin Cancer

Oxidative tissue damage is caused by many things, including cosmic rays, hydrogenated vegetable fats, fried foods, smoking and excessive sun exposure. It is also important to minimize the consumption of fats that are possibly converted to cancer causing molecules by UV radiation from the sun.

A healthy diet includes a low intake of Omega 6 fats since these are easily converted to cancer causing molecules, especially when one's diet is characterized by a lack of anti-oxidant rich fruits and vegetables. Such foods help to prevent cancer development of all kinds and this includes the development of skin cancer. They do this by preventing and reversing oxidative damage. Excessive exposure to UVA and UVB along with improper fat intake can contribute to dangerous oxidative damage.

S.A.D. or Seasonal Affective Disorder

Seasonal Affective Disorder is a term used to describe a melancholy, depressed sort of mood that afflicts many folks during the winter months. It is also a time of diminished daylight and much less exposure to sunshine and the Vitamin D that comes from it. It is therefore essential to get enough sun exposure, 10 to 15 minutes, three to four times per week, over most of your body, between the months of April and September when the sun is brightest. Since Vitamin D is stored, you'll likely make it through the winter fine if you follow this advice. Otherwise, you'd be advised to take a Vitamin D supplement. Be sure to have your blood levels checked before starting any Vitamin D supplement program. Adult levels of 25(OH)D should be 40 to 50 ng/ml but only when tested via the Dia Sorin assay.

Vitamin D Protection Against Heart Disease

More and more studies are showing the benefits of Vitamin D against heart disease. One recent study of 5,000 American men showed that those men with the lowest Vitamin D levels were 80 percent more likely to have peripheral artery disease than those in the highest 25 percent. This study was reported by the Reuters news service, but mostly ignored by the rest of the media. (14)

Summary

For more on the subject, read The UV Advantage by Dr. Holick or a recent book by Richard Hobday, The Healing Sun: Sunlight and Health.

With the excitement about Vitamin D finally penetrating the walls of several prestigious universities and some of the popular press, it is overdue for the benefits of sunshine to have finally gotten some well-deserved attention. While we are not advocating hours of sunbathing every day, one can relax in knowing that reasonable sun exposure along with a healthy lifestyle, can help them to reduce their risk of future cancer and help them to optimize their health. During the autumn and winter months, a daily 2,000 to 10,000 I.U. supplement of Vitamin D3 would be acceptable or consider the judicious use of a tanning bed, three times per week at twenty minutes per session, without sunscreen.

Meanwhile, also be sure to eat as the Center has been advocating for years, to minimize your risk of getting any form of cancer, including skin cancer.

REFERENCES:
1.  The Dark Side of the Sun: Sun Exposure and Agriculture, NASD, Dept. Biosystems and Agr’l Eng., OK St UN, 4/02.
2.  Prov. Port. Med. Cen. website “Sunshine Dangers”:  (July, 2006,
http://providence.org/hoodriver/news/n_summer_071306.htm)
3.  Buller, DB, et. al., Sun protection policies and environmental features in US elementary schools; AMC Canc. Res. Center., Arch Derm., June, 2002
4. Kennedy C, Bajdik CD, Willemze R, De Gruijl FR, Bouwes Bavinck JN; Leiden Skin Cancer Study. The influence of painful sunburns and lifetime sun exposure on the risk of actinic keratoses, seborrheic warts, melanocytic nevi, atypical nevi, and skin cancer. J Invest Dermatol. 2003 Jun;120(6):1087-93.
5.  Soll-Johanning H, Bach E. Occupational exposure to air pollution and cancer risk among Danish urban mail carriers. Int Arch Occup Environ Health. 2004 Apr 24;  6.  Br J Dermatol. 2002 Apr;146 Suppl 61:24-30
7.  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.
8.  Samanic C, Gridley G, Chow WH, Lubin J, Hoover RN, Fraumeni JF Jr. Obesity and cancer risk among white and black United States veterans. Cancer Causes Control, 2004 Feb;15(1):35-43. 
9.  Grant WB, An ecologic study of dietary and solar ultraviolet-B links to breast carcinoma mortality rates. Cancer. 2002a Jan 1;94(1):272-81 
10. Grant WB , Cancer March 2002; 94:1867-75.
11.  British Medical Journal November 22, 2003; 327:1228
12. Hayes, C.E., Proceedings of the Nutrition Society, Volume 59, Number 4, November 2000, pp. 531-535(5)
13.  Barefoot, Robert R and Reich, M.D., Carl J.: The Calcium Factor: The Scientific Secret of Health and Youth, Triad Marketing, 2002
14.  Arteriosclerosis, Thrombosis and Vascular Biology; April 16, 2008

© 2009 Tom Petrie, B.S., C.D.N.

 

 
 

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