Ultraviolet rays are not the
big, bad enemies we've been told to believe they are:
that's the message of a controversial new book that's
drawn widespread criticism from the North American dermatologists
over its implications for public safety.
From the quill of Dr Michael Holick,
a professor of medicine, physiology and biophysics at
Boston University, The UV Advantage challenges
twenty years of conventional wisdom about sun safety,
arguing "the drawbacks of sun exposure pale in comparison
with the health benefits." At the heart of his message
is the idea that North Americans have been scared into
hibernation by an overzealous cosmetics industry and
dermatologists who've joined forces to create an "anti-sunshine
hysteria that is detrimental to our health because it
converts people into sun-phobes by convincing them that
no amount of sun exposure is safe."
The result, Dr Holick says, has
been a veritable epidemic of vitamin D deficiency. And
indeed his own 1997 study of a random group of people
living in Boston, MA, showed 42% were deficient. The
good doctor blames this on our avoidance of the sun
and its ultraviolet rays that help our bodies manufacture
the vitamin. Increased sun exposure would result in
185,000 fewer cases of internal cancers (breast, ovaries,
colon, prostate, stomach and others) and 30,000 deaths
in the US along, he declares.
D
IS FOR DOUBTERS
Not surprisingly, Dr Holick's assertions have triggered
a round of stinging rebukes from dermatologists who
maintain his vitamin D talk is a load of hooey and that
we'd all do well to harbour a healthy fear and respect
for the sun.
"We know that ultraviolet radiation
is a known carcinogen and the main cause of melanoma
cancer; that incidents of skin cancer are rising every
year; and that someone dies of skin cancer every hour,"
says Dr Jason Rivers, a dermatologist and professor
of dermatology at the University of British Columbia.
A report issued in May by the Canadian Dermatology Association
concluded that there will be 30% more new cases of skin
cancer this year than there were 10 years ago ? and
that these cases would be largely preventable by taking
simple sun safety measures.
This trend is far more worrisome
to Dr Rivers than the health effects of vitamin D deficiency
which, he says, have so far been largely unproven and
underscores a carelessness in Dr Holick's message.
"The fear is that people at greater
risk will read his book and assume they should get out
in the sun or they won't get vitamin D and they'll get
cancer," says Dr Rivers. "To say that people will get
breast cancer because of low vitamin D levels is naive
and is bordering on a lack of knowledge of tumour biology.
And to come out with a blanket statement that vitamin
D reduces cancer is somewhat irresponsible."
SUNNY
MONEY
Dr Holick's findings have also come under question because
of his connection to the US tanning salon industry.
Over the next three years, as Dr Holick himself acknowledges,
he will receive $150,000 in research grants from the
Indoor Tanning Association (ITA). His assertions got
him kicked out of Boston University's Dermatology Department,
but he still heads the school's vitamin D laboratory.
At press time Dr Holick was featured on the front page
of the ITA's website, www.indoor-tanning.org.
"You can't ignore where his funding
is coming from ? he's not completely impartial," says
Dr Cheryl Rosen. Dr Rosen, who is head of dermatology
at Toronto Western Hospital, chair of the Ontario Sun
Safety Working Group and chair of the Canadian Strategy
for Cancer Control's national sun safety committee,
points out that those concerned about their vitamin
D levels can obviously find it in safer sources, namely
in food and vitamin supplements. She also counters Dr
Holick's claims of scaremongering by the dermatology
profession, noting the message has always been, and
continues to be, one of moderation.
"We are telling people to be judicious
in their sun exposure," Dr Rosen says. "We have to be
careful while out in the sun, and that means protecting
yourself as best you can with clothes, shades, a hat
and sunscreen, and avoiding peak hours of sunshine."
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