Sunbathing is a Key Element of Obtaining Excellent Health

Public health campaigns in recent years have for the most part focused on the dangers of sunlight overexposure. Also the benefits of sunscreen have been widely marketed since the 1950s by sunscreen companies.[1] This has led to a public that is cautious of sunlight exposure. It is true that overexposure to sunlight is harmful. However, underexposure to sunlight is harmful as well. Unfortunately, public awareness of the danger of underexposure to sunlight is very low. Thus, increasing the awareness of the importance of sunlight to human health represents a big opportunity to increases many people’s health.

Rickets was one of the first illnesses identified as being caused by inadequate exposure to sunlight. It is a condition seen in children that causes bone deformities and bone fractures due softening of bones.[2] A Christmas Carol by Charles Dickens, written in 1843, contained a character that personified a child with rickets, Tiny Tim. He was the crippled son of Scrooge’s employee.

For decades rickets had been a subject of much public attention. It was rampant in industrial towns and coal districts in both England and Scotland. There were many theories concerning the origin of the disease and possible treatment. Some experts blamed the venereal disease syphilis, others blamed poverty. However, it was not until WWI that enough research was accumulated to start to conquer this disease. In 1917 (three years after WWI had begun) Britain realized the addressing ill health of their young working class men was essential to their nation’s defense.  They put together a list of the major disabling diseases and invited medical researchers to work to resolve these diseases. Rickets was on this list.

War time fears prompted Edward Mellanby, a professor of pharmacology at the University of Sheffield, and his wife May Mellanby, a professor in the Household and Social Science Department of London University, to begin studying rickets. The Mellanbys suspected that rickets was due to deficiency of a fat soluble vitamin. They created rickets in puppies, and then experimented with different diets to treat the rickets. Through their work they made two critical discoveries. First, in addition to weakened bones, puppies with rickets had a bevy of additional ill health conditions including weakened teeth, heightened anxiety, and lower resistance to infections. Second, they discovered puppies fed animal fats, such as lard or fish oil avoided rickets. Specifically, they identified cod liver oil as curative for rickets.

The discovery of cod liver oil’s health benefits was a huge win. Soon many people were taking cod liver oil and were successfully avoiding and treating rickets. It was a number of years before vitamin D was discovered to be the key ingredient in cod liver oil that allows rickets to be avoided. This discovery occurred in 1922. Elmer McCollum, professor of biochemistry at John Hopkins Medical School, bubbled oxygen through cod liver oil, identifying two separate components: vitamin A and vitamin D.[3] In this same time period, it was discovered that irradiating food with ultraviolet light increased the vitamin D content of foods. This process was patented by Harry Steenbock of the University of Wisconsin. The Quaker Oats Company signed on to purchase the irradiation rights to use on its cereals in 1927, many companies followed.[4] By 1945, rickets had all but been eliminated in the United States.[5]

The discovered of vitamin D and its successful incorporation into the public’s diet has been a major triumph. However, there is more to the story.

The name vitamin D is misleading. Vitamin D is not a vitamin. It is a hormone produced by our body when our skin is exposed to the ultraviolet B portion of sunlight. The human body’s biological processes are designed to be dependent on sunlight exposure. Dietary sources of “vitamin D” can help fill the gap when a body is not exposed to an adequate amount of light; however, dietary sources of vitamin D are not equivalent to obtaining adequate sunlight exposure.

Rickets first appeared as a public health concern during the earily 1900s at the beginning of the Inductrial Revolution. Newly erected cities in northern Europe had children that were being exposed to significantly less sunlight. City living consisted of more hours indoors, sunlight was blocked by air pollution, and children often played in alleys between tightly spaced building that were closed off from sunlight. Apprearance of rickets was not the result of changes to the population’s diet, it was the result of a decrease in the amount of sunlight exposure the population received.

Rickets was resolved through a dietary solution, however, dietary sources of vitamin D do not fully resolve the detrimental affects inadequate sunlight exposure. Sensible unprotected sunlight exposure could help many, many people. However, our fear of skin cancer has overshadowed the evidence that indicates this. Cancer is a frightening, mysterious disease that has touched many people’s lives. The evidence that sunlight overexposure can cause skin cancer has terrified us into hiding under umbrellas, long sleeve shirts and hats, and slather ourselves with sunscreen. Evidence shows this has been a monstrous mistake.

Melanoma is the most dangerous type of skin cancer. It is a malignant tumor of cells that produce a dark pigment. It cause 75% of the deaths related to skin cancer.[14] Scary!!! Here is the crazy twist. The relationship between Melanoma and sunlight is baffling. As observed by the FDA, after a 1995 conference on melanoma, Melanoma is seen more often in people who DO NOT receive regular, moderate sun exposure than in those who regularly spend time in the sun.[15] Surprising, however, not hard to beleive since a number of cancers have been shown to be avoided through obtaining adequate levels of vitamin D.

The following is a brief list of the benefits of maintaining adequate levels of vitamin D[6]:

  • Bone Health: prevents osteopenia, osteoporosis, osteomalacia, rickets, and factures
  • Cellular Health: prevents certain cancers, such as prostrate, pancreatic, breast, ovarian, and colon; prevents infectious diseases and upper-respiratory-tract infections, asthma, and wheezing disorders
  • Organ Health: prevents heart disease and stroke; prevents type 2 diabetes, periodontitis and tooth loss, and other inflammatory diseases
  • Muscular Health: supports muscle strength
  • Autoimmune Health: prevents multiple sclerosis, type 1 diabetes mellitus, Crohn’s disease, and rheumatoid arthritis
  • Brain Health: prevents depression, schizophrenia, Alzheimer’s disease, and dementia
  • Mood-Related Health: prevents seasonal affective disorder, premenstrual syndrome, and sleeping disorders, elevates the sense of well-being

It is readily accepted that vitamin D is vital to human health. Unfortunately, it is not accepted that sensible unprotected sunlight exposure is needed to safely obtain an ideal amount of vitamin D. In 2002, the federal government’s National Toxicology Program announced that ultraviolet radiation had been added to the list of “known human carcinogens”.[7] Some have gone as far to say there is no such thing as a safe tan and tanning is like smoking to your skin.[8]

There is a conflict between these two commonly held medical believes that adequate levels of vitamin D are vital to human health and sunlight exposure should be avoided. The conflict is that it is very difficult to safely obtain adequate levels of vitamin D without sunlight exposure. Even 1,000 IU a day will not raise your blood levels above 30 nanograms per milliliter. Also vitamin D made in the skin lasts at least twice as long in the blood as vitamin D that is ingested from the diet.[9] Finally exposure to ultraviolet light cannot cause vitamin D toxicity. (i.e. you cannot overdoes on vitamin D by spending too much time in the sun of a tanning bed). On the other hand, ingesting large amounts of vitamin D can cause toxicity.[10] Among the consequences of vitamin D toxicity is irreversible kidney damage. [11]

Your vitamin D status can be assessed though a blood tested. A low level of vitamin D is a common health problem that is recognized by the medical community and is commonly screened for. The major circulating form of vitamin D, 25-vitamin D, is the most important vitamin D metabolite. On the lab report you may see “serum 25(OH)D”. The recommended zone for 25-vitamin D level is 40 to 60 nanograms per milliliter. The minimum level for healthy cells and maximum bone health is 30 nanograms per milliliter. The maximum level is 100 nanograms per milliliter and greater than 150 nanograms per milliliter causes intoxication. For a reference point, the average American’s level of 25-vitamin D during winter is 15 to 18 nanograms per milliliter.[12]

Part of the difficulty surrounding the role of sunlight and health is that is very difficult to give exact recommendations.  The appropriate amount of sun exposure for an individual is affected by skin color, age and the light source. If you are exposing your skin to ultraviolet light by spending time in the great outdoors, the amount of ultraviolet light your skin is exposed to is affected by your elevation, your latitude, the time of the year, the time of day, how much of your body is covered by clothing, sunscreen (if you are using sunscreen), and oil (if are using oil). The amount of UVA and UVB varies between artificial light sources.

All of these factors make it difficult to tell the public exactly how much sunlight is too much sunlight. This is the reason that the UV index was created. The UV Index assigns a value to the amount of ultraviolet light in all of the geographies around the world, and uses that index to inform the public concerning the steps that they should take to protect themselves against obtaining too much sunlight exposure.

See website for UV index info: SunWise

Since the focus of the UV Index is focused on preventing overexposure and is not at all concerned about underexposure, the recommendations are conservative in two ways that are worth considering. Number one, the UV Index is based on the UV levels at 12:00PM, the greatest UV levels of the day. Number two, the UV Index is based on light skinned people. Therefore, if you have darker skin and/or are exposing your skin to sunlight at a different time of day than noon, the UV Index represented may be overly conservative.

The UV Index deliberately does not list times until sunburn. I had to poke around on the internet for a while to find burn times related to UV Index. This is a table that I found[13]:

The goal is to get regular moderate exposure to ultraviolet light without overexposing your skin. UVA and UVB are the two wavelengths of light that affect your skin. Outdoor sunlight contains approximately 95% UVA and 5% UVB. UVB is the shorter wavelength of light. This shorter wavelength does not pass through regular glass and is what is blocked by sunscreen. It is both the wavelength that causes skin to burn and the wavelength that caused your skin to create vitamin D. Overexposure to UVB light causes your skin to burn. Overexposure to UVA does not. Sunscreen until recently only blocked UVB radiation, because UVA does not cause skin to burn. Sunscreen that only blocks UVB may have contributed to increases in skin cancer because sunscreen allowed people to spend more time in the sun without protection from UVA.  Thankfully, “broad spectrum” sunscreen have now been developed that block both UVA and UVB.

It is your life. You have to make your own decisions concerning your strategies to create the best life possible for yourself. Sensible sunlight exposure is not a practice that everyone in the medical community agrees with, but ultimately it your decision. The consequence and/or benefits of your choices are yours to live with. I hope that this blog has helped you see a new perspective and may help you in your journey towards excellent health.


~ by happydeviant on February 15, 2011.

One Response to “Sunbathing is a Key Element of Obtaining Excellent Health”

  1. I have loved your tan for years and look forward to applying small amounts on sun screen on you this summer. Just one more great post to get the word out you rock……………..

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