Vitamin
Mania: The Truth about Antioxidants
By Christopher
Wanjek
LiveScience's Bad Medicine Columnist
Studies
showing the negative or null effects of vitamins
supplements are so common that it is surprising
doctors still find these studies to be surprising.
Vitamins are not as simple as A-B-C.
The latest bit of confusion appears in the April
27 issue of the New England Journal of Medicine.
Doctors in Australia provided nearly 1,900 pregnant
women with either supplements of vitamins C and
E or a placebo to see whether the vitamins would
lower the risk of developing high blood pressure
during pregnancy. It didn't work.
Surprisingly, the doctors said, the vitamin group
had a slightly higher rate of high blood pressure
compared to the placebo group.
We love our vitamins
The levels of vitamins C and E were greater than
those found in an ordinary multivitamin tablet-1,000
milligrams of C and 400 IU of E, or roughly 10 and
20 times the recommended daily allowance. In an
editorial accompanying the study, doctors said that
supplements at these levels should not be prescribed
routinely.
But we love our vitamins.
Americans spend about $2 billion a year on vitamins
C and E, along with beta carotene (a precursor of
vitamin A) and selenium, according to Nutrition
Business Journal. These are the most popular antioxidants,
a class of chemicals said to cure just about everything.
The trouble is, science can't seem to support the
bad movie script created by the vitamin supplement
industry.
No simple movie plot...
Here's the plot, a battle between good and evil:
Rogue chemicals called free radicals roam about
the body like brazen street punks, smashing cellular
walls and roughing up innocent DNA molecules, causing
cancers and the diseases of middle- and old-age.
Their flagrant disregard for the law would continue
unchecked if it weren't for swashbuckling antioxidants
swooping in on the wings of vitamin supplements,
disarming the free radicals of their menacing electrons
and converting them into respectable molecular citizens.
But the body, it seems, is not governed by a Hollywood
"B" script. Free radicals are as good
as they are bad, and too many antioxidants may do
the body harm.
It is true that antioxidants serve as sort of a
rust protector for the body, stopping a process
called oxidation. Important molecules in the body,
such as those that form artery walls, become oxidized
when they lose an electron. Once oxidized, they
become unstable and easily break apart.
The culprit, without a doubt, is the free radical.
Free to destroy
Free radicals are highly reactive molecules or single
atoms with unpaired electrons looking for a mate.
So they steal an electron from the first thing they
encounter, perhaps a cell wall or DNA. As free-radical
damage mounts, cells can no longer perform properly.
Disease sets in. An excess of free radicals has
been cited in cardiovascular disease, Alzheimer's
disease, Parkinson's disease and cancer.
Aging itself has been defined as a gradual accumulation
of free-radical damage.
Yet free radicals are necessary for life. The body's
ability to turn air and food into chemical energy
depends on a chain reaction of free radicals. Free
radicals are also a crucial part of the immune system,
floating through the veins and attacking foreign
invaders.
Hydrogen peroxide is a prime example of a free radical.
Your blood actually contains trace amounts of hydrogen
peroxide, an internal germ fighter. In fact, you
could not fight bacteria without free radicals.
Good luck
How antioxidants work is an utter mystery, which
explains the contradicting results of very large
and well-conducted studies in the past decade showing,
for example, that vitamin E slowed the progress
of coronary artery disease but increased the risk
of a heart attack.
One thing that studies do reveal is that a diet
rich in antioxidants, as opposed to supplements,
is associated with lower rates of cancer and circulatory
disease. Richard Veech of the National Institute
on Alcohol Abuse and Alcoholism, whom I interviewed
a few years ago, sums it up best, I think:
"People don't want to exercise," he said.
"They don't want to eat healthy food. They
don't want to stop drinking; they don't want to
stop smoking; they don't want to stop having dangerous
sex. They want to take a pill. Well, good luck."
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