| Dr. Jai Maharaj 2005-05-21, 5:52 pm |
| Scientists Say Sunshine May Prevent Cancer
By Marilynn Marchione
The Associated Press
My Way News
Saturday, May 21, 2005
Scientists are excited about a vitamin again. But unlike
fads that sizzled and fizzled, the evidence this time is
strong and keeps growing. If it bears out, it will
challenge one of medicine's most fundamental beliefs:
that people need to coat themselves with sunscreen
whenever they're in the sun. Doing that may actually
contribute to far more cancer deaths than it prevents,
some researchers think.
The vitamin is D, nicknamed the "sunshine vitamin"
because the skin makes it from ultraviolet rays.
Sunscreen blocks its production, but dermatologists and
health agencies have long preached that such lotions are
needed to prevent skin cancer. Now some scientists are
questioning that advice. The reason is that vitamin D
increasingly seems important for preventing and even
treating many types of cancer.
In the last three months alone, four separate studies
found it helped protect against lymphoma and cancers of
the prostate, lung and, ironically, the skin. The
strongest evidence is for colon cancer.
Many people aren't getting enough vitamin D. It's hard to
do from food and fortified milk alone, and supplements
are problematic.
So the thinking is this: Even if too much sun leads to
skin cancer, which is rarely deadly, too little sun may
be worse.
No one is suggesting that people fry on a beach. But many
scientists believe that "safe sun" - 15 minutes or so a
few times a week without sunscreen - is not only possible
but helpful to health.
One is Dr. Edward Giovannucci, a Harvard University
professor of medicine and nutrition who laid out his case
in a keynote lecture at a recent American Association for
Cancer Research meeting in Anaheim, Calif.
His research suggests that vitamin D might help prevent
30 deaths for each one caused by skin cancer.
"I would challenge anyone to find an area or nutrient or
any factor that has such consistent anti-cancer benefits
as vitamin D," Giovannucci told the cancer scientists.
"The data are really quite remarkable."
The talk so impressed the American Cancer Society's chief
epidemiologist, Dr. Michael Thun, that the society is
reviewing its sun protection guidelines. "There is now
intriguing evidence that vitamin D may have a role in the
prevention as well as treatment of certain cancers," Thun
said.
Even some dermatologists may be coming around. "I find
the evidence to be mounting and increasingly compelling,"
said Dr. Allan Halpern, dermatology chief at Memorial
Sloan-Kettering Cancer Center in New York, who advises
several cancer groups.
The dilemma, he said, is a lack of consensus on how much
vitamin D is needed or the best way to get it.
No source is ideal. Even if sunshine were to be
recommended, the amount needed would depend on the
season, time of day, where a person lives, skin color and
other factors. Thun and others worry that folks might
overdo it.
"People tend to go overboard with even a hint of
encouragement to get more sun exposure," Thun said,
adding that he'd prefer people get more of the nutrient
from food or pills.
But this is difficult. Vitamin D occurs naturally in
salmon, tuna and other oily fish, and is routinely added
to milk. However, diet accounts for very little of the
vitamin D circulating in blood, Giovannucci said.
Supplements contain the nutrient, but most use an old
form - D-2 - that is far less potent than the more
desirable D-3. Multivitamins typically contain only small
amounts of D-2 and include vitamin A, which offsets many
of D's benefits.
As a result, pills might not raise vitamin D levels much
at all.
Government advisers can't even agree on an RDA, or
recommended daily allowance for vitamin D. Instead, they
say "adequate intake" is 200 international units a day up
to age 50, 400 IUs for ages 50 to 70, and 600 IUs for
people over 70.
Many scientists think adults need 1,000 IUs a day.
Giovannucci's research suggests 1,500 IUs might be needed
to significantly curb cancer.
How vitamin D may do this is still under study, but there
are lots of reasons to think it can:
o Several studies observing large groups of people
found that those with higher vitamin D levels also had
lower rates of cancer. For some of these studies, doctors
had blood samples to measure vitamin D, making the
findings particularly strong. Even so, these studies
aren't the gold standard of medical research - a
comparison over many years of a large group of people who
were given the vitamin with a large group who didn't take
it. In the past, the best research has deflated health
claims involving other nutrients, including vitamin E and
beta carotene.
o Lab and animal studies show that vitamin D stifles
abnormal cell growth, helps cells die when they are
supposed to, and curbs formation of blood vessels that
feed tumors.
o Cancer is more common in the elderly, and the skin
makes less vitamin D as people age.
o Blacks have higher rates of cancer than whites and
more pigment in their skin, which prevents them from
making much vitamin D.
o Vitamin D gets trapped in fat, so obese people have
lower blood levels of D. They also have higher rates of
cancer.
o Diabetics, too, are prone to cancer, and their
damaged kidneys have trouble converting vitamin D into a
form the body can use.
o People in the northeastern United States and
northerly regions of the globe like Scandinavia have
higher cancer rates than those who get more sunshine
year-round.
During short winter days, the sun's rays come in at too
oblique an angle to spur the skin
to make vitamin D. That is why nutrition experts think
vitamin D-3 supplements may be especially helpful during
winter, and for dark-skinned people all the time.
But too much of the pill variety can cause a dangerous
buildup of calcium in the body. The government says 2,000
IUs is the upper daily limit for anyone over a year old.
On the other hand, D from sunshine has no such limit.
It's almost impossible to overdose when getting it this
way. However, it is possible to get skin cancer. And this
is where the dermatology establishment and Dr. Michael
Holick part company.
Thirty years ago, Holick helped make the landmark
discovery of how vitamin D works. Until last year, he was
chief of endocrinology, nutrition and diabetes and a
professor of dermatology at Boston University. Then he
published a book, "The UV Advantage," urging people to
get enough sunlight to make vitamin D.
"I am advocating common sense," not prolonged sunbathing
or tanning salons, Holick said.
Skin cancer is rarely fatal, he notes. The most deadly
form, melanoma, accounts for only 7,770 of the 570,280
cancer deaths expected to occur in the United States this
year.
More than 1 million milder forms of skin cancer will
occur, and these are the ones tied to chronic or
prolonged suntanning.
Repeated sunburns - especially in childhood and among
redheads and very fair-skinned people - have been linked
to melanoma, but there is no credible scientific evidence
that moderate sun exposure causes it, Holick contends.
"The problem has been that the American Academy of
Dermatology has been unchallenged for 20 years," he says.
"They have brainwashed the public at every level."
The head of Holick's department, Dr. Barbara Gilchrest,
called his book an embarrassment and stripped him of his
dermatology professorship, although he kept his other
posts.
She also faulted his industry ties. Holick said the
school has received $150,000 in grants from the Indoor
Tanning Association for his research, far less than the
consulting deals and grants that other scientists
routinely take from drug companies.
In fact, industry has spent money attacking him. One such
statement from the Sun Safety Alliance, funded in part by
Coppertone and drug store chains, declared that "sunning
to prevent vitamin D deficiency is like smoking to combat
anxiety."
Earlier this month, the dermatology academy launched a
"Don't Seek the Sun" campaign calling any advice to get
sun "irresponsible." It quoted Dr. Vincent DeLeo, a
Columbia university dermatologist, as saying: "Under no
circumstances should anyone be misled into thinking that
natural sunlight or tanning beds are better sources of
vitamin D than foods or nutritional supplements."
That opinion is hardly unanimous, though, even among
dermatologists.
"The statement that 'no sun exposure is good' I don't
think is correct anymore," said Dr. Henry Lim, chairman
of dermatology at Henry Ford Health System in Detroit and
an academy vice president.
Some wonder if vitamin D may turn out to be like another
vitamin, folate. High intake of it was once thought to be
important mostly for pregnant women, to prevent birth
defects. However, since food makers began adding extra
folate to flour in 1998, heart disease, stroke, blood
pressure, colon cancer and osteoporosis have all fallen,
suggesting the general public may have been folate-
deficient after all.
With vitamin D, "some people believe that it is a partial
deficiency that increases the cancer risk," said Hector
DeLuca, a university of Wisconsin-Madison biochemist who
did landmark studies on the nutrient.
About a dozen major studies are under way to test vitamin
D's ability to ward off cancer, said Dr. Peter Greenwald,
chief of cancer prevention for the National Cancer
Institute. Several others are testing its potential to
treat the disease. Two recent studies reported
encouraging signs in prostate and lung cancer.
As for sunshine, experts recommend moderation until more
evidence is in hand.
"The skin can handle it, just like the liver can handle
alcohol," said Dr. James Leyden,
professor emeritus of dermatology at the university of
Pennsylvania, who has consulted for sunscreen makers.
"I like to have wine with dinner, but I don't think I
should drink four bottles a day."
http://apnews.myway.com/article/20050521/D8A7PB5O0.html
- - - - - - -
This makes me wonder what else they have been wrong
about.
Posted on 5/21/2005 1:47:58 PM PDT by wagglebee
- - - - - - - - - - - - - - - - - - - - - - - - - - - -
End of forwarded message
Jai Maharaj
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The terrorist mission of Jesus stated in the Christian bible:
"Think not that I am come to send peace on earth: I came not so send
peace, but a sword.
"For I am come to set a man at variance against his father, and the
daughter against her mother, and the daughter in law against her mother in
law.
"And a man's foes shall be they of his own household.
- Matthew 10:34-36.
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