The fading allure of vitamins
05/14/2007
By: Judy Foreman
My love affair with vitamins and
supplements is over: With a few exceptions -- stay
tuned -- I'm tossing them out.
Things started going south for
this romance 13 years ago when a Finnish study of
29,000 male smokers showed a higher rate of lung
cancer in men who took beta-carotene and vitamin E
and, more shockingly, found that those who took
beta-carotene had an 8 percent higher risk of death
from all causes. Two years later, an American study
reported similar findings for beta-carotene.
I've never been a smoker, but a
red flag is a red flag. Out went the beta-carotene.
Then came the bad news on vitamin
E, for which I had had high hopes as a general
disease-preventer. A 2004 analysis by Dr. Edgar R.
Miller, of Johns Hopkins University, found an
increase in deaths from all causes in people taking
more than 400 International Units a day of vitamin
E. In 2005, the Women's Health Study of nearly
40,000 healthy women showed 600 international units
of vitamin E taken every other day provided no
overall benefit for heart disease or cancer.
Out went the vitamin E.
Along the way, I tossed my
echinacea, which I once swore by for preventing or
shortening the duration of colds. (Never
underestimate the placebo effect!) Though proponents
still contend the studies are flawed, I now believe
the debunkers -- among them the researchers who
published a major study in 2005 in the New England
Journal of Medicine showing that echinacea has no
effect on colds.
Did I mention vitamin C? Oh, how I
wanted to believe this famous antioxidant would keep
me from getting cancer and all those colds! But
despite numerous studies, "we haven't been able to
show a benefit," Miller said.
The latest disillusionment came in
February with a Danish study published in the
Journal of the American Medical Association. When
the researchers pooled the data from 47 reasonably
unbiased studies involving 180,938 people, they
found a 7 percent increased risk of death from all
causes in those taking beta-carotene, a 16 percent
increased risk of death in those taking vitamin A,
and a 4 percent increased risk of death in those
taking vitamin E.
Jeffrey Blumberg , a nutritionist
and director of the antioxidants laboratory at Tufts
University, among others, said that this study was
based on flawed methodology, including the fact that
the researchers left out of their analysis a number
of studies that might have tipped the results in a
different direction. But, to me, that's clearly not
a strong endorsement of vitamins.
(An important caveat here: If I
were at risk of developing advanced age-related
macular degeneration, a leading cause of vision
loss, I would talk with my doctor about taking
vitamin C, E, beta-carotene, and zinc. A National
Eye Institute study published in 2001 showed that
this combination can slow progression of the
disease. On the other hand, a study in March in the
Archives of Ophthalmology showed no benefit to beta
carotene pills alone.)
Multivitamins? Somehow, I can't
part with mine yet, mostly because, try as I might,
I still don't eat enough fruits and veggies. But my
faith is slipping. A state-of-the-science conference
sponsored by the National Institutes of Health
synthesized data from a number of randomized,
controlled trials, the gold standard of clinical
research. In a paper published in 2006 in the Annals
of Internal Medicine, the scientists concluded,
disappointingly, that the "evidence is insufficient
to prove the presence or absence of benefits from
use of multivitamin or mineral supplements to
prevent cancer and chronic disease." (For more, go
to
consensus.nih.gov.)
Adding to the speed at which the
scales have been falling from my eyes is the latest
news from
ConsumerLab.com, a private company that tests
vitamins, both for manufacturers and consumers.
ConsumerLab reported in January
that 52 percent of the multivitamins it examined
were contaminated with lead, didn't disintegrate
properly, or had more or less of certain ingredients
than indicated on the label. While Centrum Silver
passed, a multivitamin called AARP Maturity flunked
because it failed to disintegrate properly. (An AARP
spokesperson said it believes "the validity of the
ConsumerLab study is in serious question" and is
therefore still "evaluating whether or not to
continue to make the product available.")
A children's product called Yummi
Bears Multivitamin and Mineral flunked, too, because
it contained too much vitamin A, which can be toxic.
(A spokeswoman for the company said other,
independent tests show Yummi Bears products meet all
label claims and that there is no basis for concern
about vitamin A levels in the product.) Vitamin
Shoppe Multivitamins for Women flunked because it
had too much lead; a company spokesman said last
week that the company has removed the product from
stores.
So, what's left in my dietary
supplement drawer?
Not much. Omega-3 fish oils,
vitamin D, and calcium. Omega-3's are still on my
"good" list because considerable research suggests
they lower the risk of cardiovascular disease and
abnormal heart rhythms. In ConsumerLab testing,
omega-3 fish oils, thankfully, were found to be free
of mercury, PCBs, and other potential contaminants.
Vitamin D is still on my list because it helps
protect against certain cancers and with absorption
of calcium. Calcium is still there because it seems
to help protect against bone loss, although recent
research has raised some questions, so this might be
next to go.
For me, the most pressing question
now is how to have the most fun with the handful of
twenties I'm not spending on supplements!
Judy Foreman’s column runs every other week. Past
columns are available on
www.myhealthsense.com.
Listen to her live
call-in webcast radio show every Wednesday night
from 8:30 to 9:30 EST on
http://www.healthtalk.com.
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