Does the Sun Cause Skin Cancer |
Does the sun cause cancer? That is the question. Unfortunately,
there is no clear answer.
The medical profession, and the media, have done
a good job of convincing the public to stay out of
the sun to prevent cancer. But, is there any evidence
for this claim? Surprisingly, evidence is lacking.
Furthermore, there is evidence to the contrary.
Considering a large number of people that are exposed
to the sun on a daily basis, for an extended period
of time, we would expect to see a pandemic of skin
cancer. This obviously is not happening. Athletes
and construction workers would be good examples. Yet,
there has not been an abnormally high level of cancer
occurrence in these groups. An increase of cancer
has been reported in migrant farm workers, primarily
on the back of the neck. Although, this increased
of cancer has not been attributed to the sun, but
rather exposure to herbicides and pesticides.
Sun exposure actually has beneficial effects on the
immune system, such as activation of macrophages.
In addition, sunlight reacts with cholesterol in the
skin to form of vitamin D, which has been shown to
have strong antitumor affects. The production of active
vitamin D decreases with age though. This could help
partially explain the increased risk of cancer with
age.
Ironically, it may be the sunscreens being used in
an attempt to protect the skin that may be increasing
the risk of cancer. Sunscreens often contain chemicals
that are known carcinogens.