A Toxic Sun?

With all the warnings about the sun’s harmful effects, we might consider the sun was more of a toxin than necessary for life. Today modern culture fends off the sun as if it were toxic enemy number one. Today the sales and use of sunblock, sunglasses, and wide-brim hats are ubiquitous. Can the sun be this dangerous?

What were people doing before sun block came along? Did not most humans work primarily outside all day—in the fields growing and preparing food, washing clothes, bathing, and so on? Now as we sit indoors in front of our computers, for some reason the sun has suddenly become toxic.

Most of us have experienced the positive effects of sunlight. This is why we tend to vacation in sunny areas. A vacation to a tropical or sunny destination typically results in increased feelings of well-being and relaxation. Many also experience a decrease in allergies, headaches, joint pain and backaches. While there is certainly the element of relaxation and lowered stress during vacation, it is unmistakable: Sunlight contributes to the health of the body.

The sun benefits us in a number of ways. For humans, plants and most animals, the sun’s resonating energies deliver heat, raising core body temperature. Higher core body temperatures facilitate increased cell function and greater energy. This increases our metabolism, providing increased pathways for the body’s various detoxification and purification systems. Boosted core temperatures increase cortisol levels during the day, which are balanced by increased melatonin levels, ushering greater relaxation and deeper sleep during the night.

Sun also regulates our natural biorhythm cycles. The sun’s waveforms stimulate the body’s pineal gland, which stimulates a number of key master hormones. These in turn synchronize the master body clockworks triggered through the suprachiasmatic nuclei cells. These cells mark the passage of time for the body, regulating cellular and endocrine functions. A day without sunlight will leave these cells confused. This is illustrated by the common experience of disorientation after sleeping in late on a Saturday morning. On an extended basis, a day without a good portion of natural sunlight—even if just seen through a window screen—will leave the body’s natural rhythms in a state of disarray.

The reception of light through the pineal gland is a biological process. Iguanas for example, have a parietal (third) eye centered a little higher and between the eyes, which can read and distinguish between light and dark wavelengths. When light radiation hits this area, the clock is reset. Lizards have this same mechanism and apparently other animals and humans have derivatives of this parietal eye—perhaps playing a much greater role than we have ever figured.

A lack of natural sunlight will disrupt the body’s endocrine systems. For example, German ophthalmology Professor Dr. Fritz Hollwich published in 1979 that subjects working under white fluorescent tube lighting for a period of time will result in a production of significantly higher levels of stress hormones such as adrenocorticortropic hormone and cortisol. He also found full-spectrum or natural light results lower levels of these stress hormones. Dr. Hollwich’s research was pivotal in the decision to ban white fluorescent bulbs from German hospitals.

In another study by Dr. Hollwich (Hollwich and Dieckhues 1989), 110 cataract patients underwent metabolic testing (primarily blood) before and after surgery. Prior to surgery, the opacity of their cataracts significantly reduced the amount of light, down to about 10% of normal. Testing prior to surgery showed slowed metabolism, adrenal insufficiency and hormone imbalances. After surgery—the removal of the lens opacities—metabolism and hormone levels returned to normal. These results were confirmed with another study (Hollwich and Hartmann 1990) performed shortly thereafter on fifty cataract patients with the same results. This later study also looked at water balance, blood sugar and blood cell count—all of which improved following surgery. Dr. Hollwich describes a retino-hypothalamic pathway connecting to the endocrine-visceral system.

 Dr. Niels Finsen was awarded the 1903 Nobel Prize in medicine for revealing that sunshine was extremely therapeutic for a number of infectious diseases, including lupus vulgaris, small pox, and Pick’s disease. Dr. Finsen’s famous sunbaths and separated light colors became known as Finsen Light Therapy. In the early 1900s, two Swiss physicians Dr. Bernhard and Dr. Rollier found that the sun in thin atmospheres such as the Swiss Alps provided an effective therapeutic protocol for surgical tuberculosis and lung tuberculosis. Sunlight has since been shown effective as a part of treatment for various other conditions.

About ninety percent of humans in modern society now work indoors. One hundred years ago, this statistic was reversed. At least ninety percent if not more, of humans lived and worked outside or in locations where natural light was directly present. While there are many warnings present in the medical literature to stay away from the sun as though a toxin, The National Institute of Mental Health in Bethesda, Maryland included the following statement in a 1988 report (Skwerer et al.) on seasonal affective disorder: “Along with food, air and water, sunlight is the most important survival factor in human life.”

While millions of people have been diagnosed with Seasonal Affective Disorder (or SAD) over the past few years, some estimate a good 25 million Americans are afflicted with some form of the disorder—at least the milder yet more pervasive “winter blues” version of SAD. According to Norman Rosenthal, M.D., who led the above study and most noted for many others on seasonal affective disorder, the necessity of sunlight to mental health, about 6% have SAD in the U.S. and 14% have winter blues. For some, a move from the southern latitudes to the northern latitudes precipitates the disorder. For others, there seems no connection except with other ailments, such as depression.

As the fall and winter descend upon us, sunlight hours decrease and melatonin levels increase. This is part of our natural biological cycles. However, some of us are more sensitive to melatonin for some reason. SAD and ‘winter blues’ can become a problem in these more sensitive folks. It seems that women are also more likely to come down with the disorder.  

A number of diseases are attributable to lower levels of sunlight. Hypertension, atherosclerosis, early dementia, Alzheimer’s, multiple sclerosis, psoriasis, fibromyalgia, depression, arthritis, and low back pain are but a few of the issues which have been linked to a lack of, or ameliorated by sun exposure. A lack of natural sunlight depresses the immune system, weakens eyesight, lowers endocrine activity—lowering and/or disrupting hormone secretion—lowers concentration, increases stress and contributes to depression. In addition, sunlight has been shown to decrease symptoms and duration of several cancers, especially as they relate to melatonin levels. Studies have also shown that natural sunlight decreases hyperactivity in children.

In the converse, an increasing amount of research is indicating that a lack of sunshine during the day combined with the lack of complete darkness during the night—as our environment has become increasingly lit up at night—reduces melatonin availability. This reduction in melatonin has been linked with various types of cancers, including breast cancer, prostate cancer, colorectal cancer and endometrial cancer (Reiter et al. 2007). 

In a study done by the Heschong Mahone Group (1999), students learning within environments with the most natural sunlight tested better and exhibited faster rates of learning. Another study supporting this was conducted earlier by Anderson et al. (1991).

Energy conversion from the sun is not limited to plants. From the sun’s ultraviolet B rays, our bodies synthesize vitamin D₃. By far the most important of the D₃ is produced when ultraviolet-B in wavelengths of 270-290 nanometers enters our epidermis. Here a derivative of cholesterol called 7-dehydrocholesterol undergoes a conrotatory electrocyclic reaction to produce a pre-vitamin D. This later molecule undergoes hydroxylation in the liver and kidneys to convert to the final D₃ structure, 1,25 dihydroxyvitamin D (some refer to this as 25-OHD). The conrotary reaction illustrates another synchronous circular reaction as atoms and their bonds rotate around the ring.

In the environment of the 7-dehydrocholesterol molecule within the epidermis, melanin—the element which makes the skin turn brown—provides a filtering mechanism for the rays. The greater the melanin level, the fewer ultraviolet-B rays reach the 7-dehydrocholesterol molecules, and thus the less vitamin D₃ is produced.

Vitamin D is most known to regulate calcium levels and absorption. Without proper vitamin D₃ production, calcium will be absorbed into our bones and teeth. Vitamin D is also critically important for healthy immune function, nervous function, cardiovascular health, mood regulation, pain regulation, insulin/blood sugar balance, as well as numerous endocrine and digestive functions. Vitamin D is a necessary component for good health, and its most natural form (D₃) comes from natural sun exposure (Lehmann 2005).

Because vitamin D₂ will also convert to 1,25 dihydroxyvitamin D; until recently it was assumed D₂ and D₃ were functioned identically within the body. This assumption has since been proven to be incorrect. In a study done at the Creighton University and the Medical University of South Carolina (Laura et al. 2004), twenty healthy males were measured following supplementation of D₂ and D₃. While both converted to 1,25 dihydroxyvitamin D, D₂ converted at far less levels and fell off much earlier. The study’s authors concluded that D₂ has only about one-third the potency of D_3.

In a Boston University study published in 2008, forty-five nursing home patients took a multivitamin containing 400 IV of vitamin D₂. During the study period, their 25-OHD levels registered deficient from a range of 49% to 78% in measurements over an eight-month period.

In 1998 (Thomas et al.) a study of 290 medical ward patients at the Massachusetts General Hospital in Boston showed 57% were vitamin D deficient (164) and 65 of those (22%) were severely deficient. 46% were deficient despite taking the recommended dosage of supplemental vitamin D. The elderly and those in pain are most often vitamin D deficient. One study (Al Faraj and Al Mutairi 2003) found 83% of 360 low-back pain patients had vitamin D deficiency and another (Plotnikoff and Quigley 2004) showed that 93% of 150 nonspecific pain patients had vitamin D deficiency. In the latter study nearly all of those patients declared pain relief after three months of vitamin D supplementation, and in the former study, of the 360 low-back pain patients, 95% showed clinical improvement after treatment with supplemental vitamin D₃.

Clinical studies have also indicated a 20-30% increase in breast cancer incidence and a 10-20% increased fatality rate for breast cancer among vitamin D-deficient women (Nielsen 2007). Chronic kidney disease is also more prevalent among those deficient in vitamin D (Khan 2007). Vitamin D deficiency was linked to tuberculosis by Sita-Lumsden et al. in 2007. Vitamin D has also shown to protect against macular degeneration by Parekh in 2007. Cognition and mood related disorders are also linked with vitamin D deficiency (Berk 2007). Vitamin D deficiency was linked to a higher incidence of osteoporosis by Barone (2007). Fetal diabetes, pre-eclampsia and fetal neurological disorders were connected to vitamin D deficiency by Perez-Lopez in 2007. Serum vitamin D was also connected with higher insulin sensitivity by Kamycheva et al. in 2007.

Vitamin D, when taken together with calcium, was linked to greater glucose metabolism by Pittas et al. in 2007. In a Creighton University study (Lappe et al. 2007) of 1179 postmenopausal women, cancer rates among those supplementing with calcium and vitamin D₃ had an almost 60% lower cancer rate than the control subjects. A number of cancers are apparently prevented or ameliorated by vitamin D.

The active and most therapeutic version of vitamin D is 1,25-dihydroxyvitamin D₃, most effectively produced through the conversion of sunlight. It is also thought that the availability of 1,25-dihydroxyvitamin D in the tissues and bloodstream is raised—and possibly somewhat regulated—by the levels of isoflavones in the body. Isoflavones are nutrients available in various plant foods, with higher levels in grains and beans (Wietrzyk 2007).

In the Boston University 2008 press release noted above, tanning beds produced therapeutic levels of 1,25-dihydroxyvitamin D_3. While this information might be considered useful for extreme therapeutic cases of deficiency, other studies have reported higher incidence of melanoma among tanning bed users. In one study of 551 persons, those who used tanning beds more than 20 minutes per session had significantly higher rates of malignant melanoma (Ting et al. 2007).  

Conservative sunlight exposure provides sufficient vitamin D. Just twenty minutes of sunlight on the arms, hands and face will produce about 400 IU of vitamin D on the average skin type. A day of summer sun in a bathing suit until the skin is pink will produce as much as 20,000 IU. A day in the tropics could easily result in 100,000 IU/day. Although the RDA is 200-700 IU (700 for elderly adults), many nutritionists believe that 1,000 to 5,000 IU per day is optimal. Note that an SPF-8 sunscreen will block about 95% of vitamin D synthesis.

Not many foods contain vitamin D. It is found in various dairy products such as cheese, butter, and cream, and in some fish and oysters, but the sun or supplements are the most reliable sources.

The human body requires sunlight levels above 2500 lux before it can stimulate any significant levels of endogenous vitamin D. Indoor lighting simply does not supply enough of the correct waveforms to stimulate significant conversion of vitamin D. Indoor light ranges from 60 lux at low lamp level to 200 lux in average indoor lighting. The brightest indoor lighting might produce about 1000 lux. Levels of over 1000 lux typically require some sort of daylight.

 

Copyright 2008 Casey Adams