There
might be a time when instead of just drinking that morning cup of
coffee you lather it on your skin as a way of preventing harmful sun
damage or skin cancer.
A
new Rutgers study strengthens the theory that caffeine guards against
certain skin cancers at the molecular level by inhibiting a protein
enzyme in the skin, known as ATR. Scientists believe that based on what
they have learned studying mice, caffeine applied directly to the skin
might help prevent damaging ultraviolet light from causing skin cancer.
Prior
research indicated that mice that were fed caffeinated water and
exposed to lamps that generated UVB radiation that damaged the DNA in
their skin cells were able to kill off a greater percentage of their
badly damaged cells and reduce the risk of cells becoming cancerous.
“Although
it is known that coffee drinking is associated with a decreased risk of
non-melanoma skin cancer, there now needs to be studies to determine
whether topical caffeine inhibits sunlight-induced skin cancer,” said
Allan Conney, director of the Susan Lehman Cullman Laboratory for Cancer
Research.
In
this newly-published study, instead of inhibiting ATR with caffeinated
water, Rutgers researchers, in collaboration with researchers from the
University of Washington, genetically modified and dimished the levels
of ATR in one group of mice. The results: the genetically modified mice
developed tumors more slowly than the unmodified mice, had 69% fewer
tumors than regular mice and developed four times fewer invasive tumors.
When caffeine was topically applied to the regular mice, they had 72%
fewer squamos cell carcinomas, a form of skin cancer.
The
study also found, however, that when both groups of mice were exposed
to chronic ultraviolet rays for an extended period of time, tumor
development occurred in both the genetically modified and regular mice.
What this seems to indicate, says Conney, is that inhibiting the ATR
enzyme works best at the pre-cancerous stage before UV-induced skin
cancers are fully developed.
According
to the National Cancer Institute, sunlight-induced skin cancer is the
most prevalent cancer in the United States with more than 1 million new
cases each year. Although multiple human epidemiologic studies link
caffeinated beverage intake with significant decreases in several
different types of cancer, including skin cancer, just how and why
coffee protects against the disease is unknown.
“Caffeine
might become a weapon in prevention because it inhibits ATR and also
acts ad as a sunscreen and directly absorbs damaging UV light,” said
Conney.
