Sunlight & Your Health

by Judie Gaillard and Donald L. Smith

Year after year, the anti-tanning establishment wages a war against the practice of tanning--whether indoors or outdoors. The scare tactics reverberate warnings of developing skin cancer as a result of too much sunlight. In fact, some in the medical arena suggest limiting exposure to ultraviolet light, while downplaying the importance UVR plays in our lives and health.

However, they fail to inform the public of the positive benefits of UVR, including curbing the risk of developing certain types of cancer. It probably is safe to say that all of our lives have been or will be touched by cancer. It is an invasive and sometimes savage threat to our overall health and well-being. However, recent studies have revealed that sensible, moderate and responsible exposure to UVR may help reduce the risk of developing certain types of cancers, including breast and prostate cancers.

Breast Cancer

The benefits of UVR outweigh the minimal and manageable risks involved, especially if you consider that maintaining optimal levels of vitamin D appears to reduce the relative risk of developing breast cancer. As we all know, exposure to UVR helps produce vitamin D in our bodies and optimal levels of vitamin D is believed to help reduce the relative risk of developing breast cancer.

Let's look at the facts. In 1998, 180,300 women were diagnosed with breast cancer and 43,900 died from it. This means for every four people diagnosed with breast cancer, one dies from the disease--making it the most lethal form of cancer for women.

Wouldn't it make sense that anything with the potential to reduce the relative risk of developing breast cancer--such as UVR--be given a high priority from a public policy and compassion point of view?

This is why a recent study conducted by Ester M. John and associates at the Northern California Cancer Center is so important. The study, titled "Vitamin D and Breast Cancer Risk: The NHANES I Epidemiologic Follow-up Study, 1971-1975 to 1992" says that casual sunlight, along with other factors, can help reduce the risk of breast cancer.

In the report the authors stated, " ... we found that high exposure to sunlight was associated with a 25 percent to 65 percent reduction in breast cancer risk among women whose longest residence was in a state of high solar radiation."

The report also says, "No reductions in risk were found for women who lived in regions of low solar radiation."

Finally, the study stated, "Our results would be particularly promising for the primary prevention of breast cancer because dietary vitamin D and casual sunlight exposure are modifiable lifestyle factors," all of which combine to provide a course of action for women wishing to reduce their relative risk of this dreaded disease. (It is important to note that men also can develop breast cancer).

However, let's review what the authors of the study said before discussing the course of action that can be taken to help reduce the relative risk of developing breast cancer.

Living in the Southern or Southwestern United States where the level of ambient sunlight is higher year-round provides residents with significant benefits. One such benefit is the maintenance of higher levels of vitamin D--the components of sunlight that induce the production of vitamin D are the ultraviolet radiation (UVB, UVA2 and UVA1) wavelengths.

When the authors speak of modifiable lifestyle factors that are particularly promising for the primary prevention of breast cancer, one answer could be moving from areas of lower solar radiation (northern latitudes) to areas of higher solar radiation (southern latitudes). Unfortunately, that approach is not very realistic; however, that same objective can be obtained by a program of sensible, moderate and responsible tanning at an indoor tanning salon.

This is easy to accomplish, relatively inexpensive and provides other benefits. For those of you interested in reducing your relative risk of breast cancer by 25 percent to 65 percent, begin a regimen of sensible, moderate and responsible exposure to UVR. This can best be accomplished by visiting an indoor tanning salon where both women and men can be assured of a controlled supply of UVR that is not seasonal or weather-dependent.

As mentioned before, there were 184,300 new cases of breast cancer diagnosed in 1998. A 25-percent reduction in that number would mean 46,075 women would not have suffered the trauma of this disease. Moreover, the mortality toll of 43,900 would have been reduced by almost 11,000 deaths.

Therefore, there is no question that a plan of action that has the potential of reducing the relative risk of breast cancer by even just 25 percent is eminently worthwhile. That course of action should include taking a vitamin supplement that provides a daily vitamin D intake of at least 200 international units in addition to routine exposure to UVR.

Non-Melanoma Skin Cancer

If you are wondering whether exposure to UVR increases your risk for skin cancer, let's examine the facts.

In 1998, only 1,200 deaths were attributed to non-melanoma skin cancer--the only form of skin cancer shown to link with repeated overexposure to UVR. On a sex-adjusted basis, there were more than 70 deaths from breast cancer for every one death from non-melanoma skin cancer.

Furthermore, the concept of sensible, moderate and responsible exposure to UVR advocated by the indoor tanning industry means that overexposure--defined as a dose of UVR that will cause sunburn--is avoided, thereby reducing the minimal and manageable risks involved.

That being stated, the possible reduction of the relative risk of developing breast cancer by 25 percent to 65 percent is a powerful reason to support the notion that sensible, moderate and responsible exposure to UVR far outweigh the minimal and manageable risks involved.

Prostate Cancer

Prostatic cancer is the second most common cause of death from cancer in men of all ages and the most common cause of death from cancer in men over age 75. The good news is that prostatic cancer rarely is found in men younger than age 40. In 1998, 184,500 men were diagnosed with prostate cancer and 39,200 died. This means that for every 4.7 men diagnosed, one died from prostatic cancer.

A recent study by Hanchette and Schwartz of the University of North Carolina published in the journal Cancer contained important information for all men. The study, titled "Geographic patterns of prostate cancer mortality--evidence for a positive effect of UVR", supports the hypothesis that UVR may protect against clinical prostate cancer.

Viewed with other recent data, including those demonstrating a differentiating effect of vitamin D on human prostate cancer cells, these findings suggest that vitamin D may have an important role in the natural history of prostate cancer.

In their article, Hanchette and Schwartz stated a number of important findings. For instance, they stated that "because the major source of vitamin D is casual exposure to UVR, the authors examined the geographic distributions of UVR and prostate cancer mortality in 3,073 counties of the contiguous United States."

The study found that "the geographic distributions of UVR and prostate cancer mortality are correlated inversely. Prostate cancer mortality exhibits a significant north-south trend, with lower rates in the south."

The study's data also showed there was a 20-percent to 40-percent lower incidence rate of prostate cancer among men in southern latitudes, while men with skintype 6 skin (African Americans) had a much higher incidence rate in all areas than did skintype 1-4 men (Caucasian).

So what can residents of northern and eastern states, as well as African American men, do to reduce their relative risk of developing prostate cancer? Are they doomed to have a higher risk of developing this disease because they live in the wrong part of the country and/or have darker skin color?

Since there is no such thing as artificial UVR, it is possible that routine, year-round sensible, moderate and responsible exposure to UVR in an indoor tanning bed may bring about a significant reduction in the relative risk of developing prostate cancer while also developing a cosmetic tan.

To substantiate this is an article published in European Urology by D.M. Peehl. The article, titled "Vitamin D and Prostate Cancer Risk," substantiated the premise set forth by Hanchette and Schwartz. Dr. Peehl stated that evidence from diverse areas of study--epidemiologic, molecular, genetic, cellular, animal models and clinical trials--suggests that vitamin D may be an effective preventive agent against prostate cancer.

What does this mean? Is the possibility of a 20-percent reduction of the relative risk of developing prostate cancer important? As mentioned previously, there were 184,500 new cases of prostate cancer diagnosed in 1998. A 20-percent reduction would mean that 36,900 men would not suffer the trauma of this disease. In addition, the mortality toll of 39,200 would have been reduced by approximately 8,000 deaths.

Again, it is not necessary to fear developing non-melanoma skin cancer by tanning indoors. As stated, in 1998, only 1,200 deaths were attributed to non-melanoma skin cancer--the only form of skin cancer shown to have a link with repeated overexposure to UVR.

Therefore, on a sex-adjusted basis, there are more than 65 deaths from prostate cancer for every one from non-melanoma skin cancer. Sensible, moderate and responsible exposure to UVR, advocated by the indoor tanning industry, means that overexposure is avoided--so the minimal and manageable risks of non-melanoma cancer are reduced.

It is known that prostate cancer is a progressive, multi-step disease and that by age 30, approximately 20 percent of all men have microscopic cancer. And since the incidence steadily increases, by the time a man is age 90 he is more likely to have prostate cancer than not.

Why then, despite the high incidence of microscopic cancer, do only 8 percent of the men in the United States develop clinically significant prostate cancer? Is it possible that vitamin D is one of the most important and effective preventive agents against prostate cancer? If so, anything that can help a man maintain year-round optimal levels of vitamin D should be considered--and routine indoor tanning is the ideal way to accomplish this objective.

Furthermore, the evidence supporting the fact that African American men have a higher incidence and mortality rate of prostate cancer is alarming. Remember, skintype 6 individuals have four times more tolerance to UVR than do skintype 2A individuals and, therefore, require higher levels of exposure to stimulate the equivalent production of vitamin D.