hair and cancer linked
With the incidence of melanoma on a constant upswing (it has
increased 2000 percent since 1930 in the United States) scientists
are eager to learn everything they can about solar radiation and
its effect on the skin.
More time spent in the sun, the oft-mentioned depleted ozone
filter in the atmosphere and better detection are all blamed for
the general increase – but why are redheads and blonds two
to four times more likely than others to develop the disease?
A Duke University chemist may have identified one reason that
redheads develop more skin cancers. In studies with a highly precise
laser, John D. Simon found that skin pigments common to people
with red hair and black hair react differently to ultraviolet
light. Pigments from the redhead group in particular were more
likely to create free radicals – molecules that harm DNA
and might cause cancer.
Using a specialized microscope and the help of N.C. State University
physicist Robert Nemanich, Simon documented this process, when
photons of ultraviolet light are absorbed by microscopic pigment
particles, during which process electrons might be knocked loose.
Simon presented his findings Sunday at the national meeting of
the American Chemical Society in Washington, noting excitedly
that “No one has been able to observe this before!”
Though not yet a definitive cause of cancer, these findings do
fit with previous studies on human skin cells and laboratory mice
that have shown that pigment common to redheads – and fair
skin in general – reacts more readily to the invisible radiation
that leads to sunburn and wrinkles.
“There are a zillion steps to this process,” said
Lowell Goldsmith, a dermatologist who researches genetic causes
of skin disease and edits the journal Investigative Dermatology. “Maybe
it can be interfered with at many points.”
To obtain samples for the study, Simon and his team contacted
wig manufacturers for black hair, but found the much rarer red
hair more difficult and expensive to obtain. Instead, the team
financed free haircuts for redheads on Duke’s campus.
The team studied the pigments, called melanin, obtained from
the hairs. Those samples are thought to be chemically similar
to the pigments embedded in skin cells, which are very difficult
In Duke’s Free-Electron Laser Lab, they found that it took
high-energy ultraviolet light (that which is normally filtered
out by the atmosphere) to loosen electrons from the pigment isolated
from black hair. Pigment from red hair, however, also changed
after exposure to lower-energy ultraviolet light, which does penetrate
the atmosphere to reach Earth.
Simon speculates this vulnerability may be shared by all fair-skinned
people, because they and redheads tend to have ample supplies
of the same type of pigments embedded in their skin cells.
Interest in this study spreads far beyond scientists’ research
labs, to the homes and lives of ordinary people. Shannon Klappenbach
of North Raleigh is all too familiar with the dangers of the sun
on fair skin.
Herself a redhead with three fair-skinned sons (two also redheads),
Klappenbach keeps stashes of sunscreen – preferably 45 or
50 SPF – around the house, in her car and in her purse.
No one goes outside until back, front, face, arms and legs have
been fully slathered.
She’s rooting for scientists to find better ways to protect
her children. “Whatever they have,” she said, “I
would want to hear about it.”