Editor's note: To see Offit's interview with Dr. Sanjay Gupta, check out "Sanjay Gupta, M.D." Saturday at 4:30 p.m. and Sunday at 7:30 a.m.
(CNN) -- Dr. Paul Offit doesn't take any vitamins.
In fact, while you might
think that vitamins are great in any quantity, Offit urges you to take a
step back and think before swallowing the equivalent of eight
cantaloupes in a single dose.
"I think that alternative
medicine is often given a free pass," he told CNN chief medical
correspondent Dr. Sanjay Gupta. "I think we should hold alternative
medicine to the same standard that we hold conventional medicine. It
lives under this sort of untouchable halo. I think we should be a little
more skeptical."
Offit, chief of the
division of infectious diseases at the Children's Hospital of
Philadelphia, is no stranger to controversy -- previously he has taken
on the anti-vaccine movement. His book "Do You Believe in Magic? The
Sense and Nonsense of Alternative Medicine," came out Tuesday.
Vitamins and supplements, representing about a $27 billion industry,
are necessary to convert food into energy, but it's possible to take
them in excess, Offit said. For instance, it's not uncommon to hear of
someone taking 1,000 milligrams of vitamin C, but that's about the same
amount in 14 oranges.
"Vitamins live under this
notion that you can't possibly hurt yourself," he said. "But you can,
by challenging Mother Nature and taking these vitamins and concentrating
them to these exceptionally large quantities that you would never
normally eat."
You may have heard the
term "antioxidant" as a buzzword that applies to some vitamins.
Antioxidants combat free radicals -- molecules produced when your body
breaks down food, or by environmental exposures like tobacco smoke and
radiation, according to the National Institutes of Health. Free radicals damage cell membranes and DNA.
Doctors recommend a
healthy intake of fruits and vegetables containing antioxidants to
prevent this from happening and apparently decreasing the risk of
conditions such as cancer and heart disease.
However, oxidation is
necessary for life, and preventing too much of this process can be a bad
thing because cells that need to be destroyed, such as cancer cells,
won't be.
There have been several important studies showing the harmful effects of vitamins.
As Offit wrote in an op-ed the New York Times, a 1994 New England Journal of Medicine study on
29,000 Finnish smokers found beta carotene was associated with lung and
heart disease death. Beta carotene and vitamin A in combination were
shown in another New England Journal of Medicine study to be linked to a 46% greater risk of death from lung cancer than placebo.
A 2012 Cochrane review of multiple randomized clinical trials showed an increase in risk of death may be linked to beta carotene and vitamin E, as well as higher doses of vitamin A.
The likely explanation,
Offit said, is that supplemental antioxidant vitamins, taken in large
quantities, cause unnatural behavior in the body, counteracting
oxidation too much and leaving the immune system weaker in its defenses
against invaders.
In response to Offit's op-ed, the nonprofit Consumer Healthcare Products Association
countered that there is research underscoring the benefits of
multivitamins, and that these supplements are prominent in the health
care regime of many consumers.
"Consumers should always
use caution when considering 'megadoses' of any supplements, carefully
research these choices, and consult a healthcare professional with
questions," the CHPA said. "While Dr. Offit shares his own hypothesis on
supplemental antioxidants in this piece, it has yet to be
substantiated. Until that time, we look forward to future research that
would provide guidance for public health."
The Council for Responsible Nutrition,
a trade association representing the dietary supplement industry,
reacted strongly to Offit's book, saying he "weaves together a series of
tired old arguments."
"Dr. Offit's credentials
as a respected medical physician are well-established, making his
dismissal of the value of dietary supplements all the more unfortunate,"
council president Steve Mister said in a statement.
"With more than 150
million Americans taking dietary supplements each year, it would be a
shame if consumers reading this book mistake the opinion of one doctor
for the opinion of the medical community as a whole. It is important for
consumers to have an open dialogue with their health care practitioners
about their dietary supplement regimens, and hopefully this book won't
deter them from doing so."
The abundance of strong
studies on the harmful effects of megavitamins suggests to Offit that
these supplements are worse than Vioxx. That was an anti-inflammatory
drug that its manufacturer, Merck, voluntarily withdrew from the market
in 2004 after evidence emerged of its harm to the heart in some people.
"I think if vitamins
were a regulated industry, you could argue that megavitamins would have a
black box warning on them," he told CNN.
Because the industry is
not regulated, no one knows if alternative remedies are actually the
same, or have a standard concentration, from batch to batch. No safety
or efficacy data is available, either, the way there is with
pharmaceuticals regulated by the U.S. Food and Drug Administration.
"I think people have the
misconception that these products -- dietary supplements and vitamins
-- are made by elves and old hippies that have meadows and flowers," he
said.
The 1994 Dietary
Supplement Health and Education Act had the effect of defeating the
FDA's attempt to regulate the supplements industry, so consumers don't
know what they are buying, Offit said.
"We are the victims of enormous marketing campaign regarding some of these vitamins and supplements," he said.
Despite the widespread
popularity of vitamins and supplements, doctors shouldn't encourage
patients to take these substances just because they want them, he said.
"I think the message is this: That patients are not customers, and we're
not waiters."
By: Elizabeth Landau
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