Question:
I am still using the tanning bed every other day. People are beginning to admonish me on the possibility of skin cancer. (I've gone into this with the attitude, I just can't worry about everything, but I am curious: WHAT ABOUT SKIN CANCER?
Answer:
There certainly is a risk of skin cancer with exposure to UVR. However I
suggest that some of those offering you advice are well intended yet perhaps
ill informed. I suggest that the prevalence of skin cancers from UVR is due
largely from inappropriate exposure times and frequencies and susceptible
skin characteristics. If you have an modest tolerance to UVR and observe
moderate exposure durations you should be OK. Bear in mind you could also
take D3 supplements in order to attain an therapeutic immunosuppressor
benefit.
The following is an excerpt from Grant's yet to be published book entitled
An estimation of excess cancer mortality in the United States due to
inadequate doses of solar ultraviolet-B radiation and/or vitamin D.
As a check on the approach used in this work to determine the excess
mortality due to insufficient solar UV-B radiation is to do the same
analysis on melanoma and other skin cancer. The results, given in Tables
2-3 based on those living in rural areas for July 1992 , show that the
mortality rate for melanoma for the regression value for no solar UV-B is
approximately half the average mortality rate, while for other skin cancer
it is less than 10% of the average for males, but 40% of the average for
females. The mortality rates are generally in the southwest U.S., which has
a larger fraction of Hispanics among the white population, which may affect
the results since they have darker skin pigmentation. These results are in
general agreement with the literature that basal cell carcinoma (BCC) and
squamous cell carcinoma are fairly directly related to solar UV exposure up
to certain levels, moderated to some extent by genetics and skin
pigmentation, and, perhaps, diet, while melanoma is less well related to
solar UV exposure. Melanoma seems to be more related to intermittent sun
exposure than continuous sun exposure. However, the epidemiology of BCC and
melanoma are complicated by several factors including the existence of
subgroups of these diseases which do not appear to be caused by sun
exposure.
However, the results in Tables 2-3 indicate that 12% of the melanoma deaths
occurred due to too much solar UV-B, while 31% of the males and 8% of the
females died from other skin cancer for the same reason. The finding that
such a low fraction of the deaths are attributed to solar UV-B exposure in
this analysis suggests that either: (1) the usual estimates that about 2/3
of melanoma and most of other skin cancer mortality is due to excess UV-B
radiation is too high; or (2) or that this approach is subject to a number
of confounding factors that cannot be modeled, such as genetics, life style,
dietary factors, migration, etc. The latter is more likely. Thus, the
estimates of excess mortality due to insufficient UV-B and/or vitamin D are
likely to be underestimates.
Grant also attributes many cancers to inadequate vitamin D3.
Results: The present study confirms previous results that UV radiation
reduces the risk for 9 types of cancer (breast, colon, kidney, myeloid
leukemia, ovary, pancreas, prostate, and rectum and non-Hodgkin's lymphoma)
and extends the results to cancer of the bladder, esophagus, gallbladder,
other billiary tract, and stomach.
