Lack of Ultraviolet-B Radiation is a Major Cause of Many Types of Cancer

William B. Grant, Ph.D.12 Sir Francis Wyatt Place, Newport News, VA, 23606-3660 U.S.A.,1-757-599-9811 (voice), 1-757-870-8434 (cell), [email protected]

Embargoed until 4:00 p.m. EST (2100 hours GMT) March 14, 2002

During the past two decades, ultraviolet-B (UV-B) radiation from the sun has been blamed for a significant increase in melanoma and other skin cancer. However, during the same period, there have been many articles in reputable journals indicating that sunlight actually affords protection against many other types of cancer. Using powerful statistical techniques developed for environmental research, a new study has been done to quantitatively determine how many additional cancer deaths are caused each year in the U.S. by lack of sufficient UV-B radiation, so that its total effects on cancer rates can be assessed more accurately.

The study, which was published in the March 15th issue of Cancer, used the cancer mortality data reported for 500 areas in the U.S. for 1970-1994. These data were recently posted by the National Institutes of Health and the National Cancer Institute on the Internet (http://cancer.gov/atlasplus/type.html). The data show that the mortality rates for white-Americans for bladder, breast, colon, corpus uteri, esophageal, ovarian, rectal, and stomach cancer were about twice as high in New England as they were in the southern states. Similar north-south patterns were also found for African-Americans.

More detailed analyses showed that the cancer rates for the various regions of the United States were inversely related to the amount of UV-B to which the population was exposed, even when corrected for most other known factors. For the year 2002, it can be conservatively expected that lack of sufficient UV-B radiation exposure in many parts of the country will lead to approximately 85,000 additional cases from about a dozen types of cancers out of 1,285,000 projected cases and 30,000 additional deaths out of 555,000 projected deaths compared to what would occur if the entire country could obtain the same UV-B exposure as is found in the southern part of the country. It is also estimated that 35,000 of the 204,000 breast cancer cases and 7,000 of the 40,000 breast cancer deaths in the U.S. are related to insufficient UV-B radiation, as well as about 25% of the breast cancer rates in Europe. By way of comparison, the total number of additional deaths that might occur from melanoma and other skin cancer in the U.S. due to that same increased level of UV-B exposure would be about 3,000.

The ideal case would, therefore, be to find some way of obtaining the beneficial effects of UV-B exposure without suffering the increased incidence of skin cancer. This may well be possible, since the most likely reason for the protective role of UV-B is to initiate the production of the D-vitamin 25(OH)D3, a vitamin well known to reduce the risk of cancer. However, it has not yet been shown that vitamin D3 supplements would act as a direct substitute for increased exposure to UV-B radiation and, if so, what amounts are required. Thus, further studies into the relationship between this inexpensive vitamin, regional UV-B radiation doses, lifestyle and other personal factors, and the rates of different types of cancers should be extremely worthwhile, having the potential to prevent many cases of cancer and save many lives now lost to cancer annually in the United States.

William B. Grant, Ph.D., is a scientist who does independent research on the dietary and environmental links to chronic diseases. He may be reached at the contact points given above for further information.

Grant WB. An estimate of premature cancer mortality in the United States due to inadequate doses of solar ultraviolet-B radiation, a source of vitamin D, Cancer, 94(6), 1867-1875, March 15, 2002.

See, also: Grant WB. An ecologic study of dietary and solar UV-B links to breast cancer mortality rates. Cancer, 94, 272-281, Jan. 1, 2002.

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