BY: ALEX A. AVERY AND DENNIS T. AVERY
CHURCHVILLE, VA—Way back in 1946, the esteemed British medical journal the Lancet
declared in an editorial that organic fanatics were making health and
nutrition claims way beyond what the science supported. Oh how little
has changed since then.
The media is once again pronouncing organic food superior based on
science fad and the findings of a single study taken well beyond what
the evidence shows.
The latest salvo in this debate is a simple study of processing
tomatoes (the kind used to make paste and sauces) grown over the past
decade by a group of California researchers. The researchers, led by
Dr. Alyson Mitchell, report that irrigated processing tomatoes grown
using organic methods contained roughly twice as much of two flavonoid
antioxidants, quercetin and kaempferol.
These are the two most abundant “flavonoids” in our diet “linked” to
reduction in some forms of cancer and lower blood pressure, which
reduces the risk of heart disease and stroke. Link means “far from
provent” in science, but the media thrives on rumor. Hence, the river
of newspaper ink spilled in the past month on how organic vegetables
and fruits “really are better for you” because they are “full of
antioxidants.”
Whether the findings have any bearing on your health or on flavonoid
levels in organic tomato paste at your local market are both completely
unknown.
For example, the organic tomatoes used twice as much irrigation
water as the conventional ones – in a state that is already desperately
short of fresh water. They were also provided one-third more nitrogen
and 3-fold more phosphorus each year than the conventional tomatoes via
cow manure fertilizer. Yet California only has enough animal manure to
support about 10 percent of its current produce production. Unless the
organic tomato paste you buy is grown specifically under these
conditions with the same tomato variety, who knows what the flavonoid
levels will be.
If you really want to be sure to get “more” flavonoids, Unilever
Research and the University of Exeter have developed a GM line of
tomatoes that produce as much as 78-fold more flavonoids without
special growing requirements. Now that’s a difference!
But even that may not mean much. While there is evidence that eating
some fruits and vegetables is healthful, consuming lots, or more
flavonoids or antioxidants has yet to show any health benefits
whatsoever.
In a new follow-up study of more than 3,000 breast cancer survivors
followed for over 7 years published in the July issue of the Journal of the American Medical Association,
women who ate up to 12 servings of fruits and vegetables each day had
exactly the same recurrence and new cancer rate as women who ate only
five a day. This lack of change in cancer incidence despite a doubling
of consumption in antioxidants is a fly in the organic sauce. Perhaps
they are suggesting we can get the benefits of 5 servings of fruits and
vegetables by eating only two servings of organic – which would be good
considering organics cost twice as much.
All of this assumes that flavonoids and antioxidants truly have
anti-cancer benefits, and no studies have yet actually shown that. In
fact, it was not long ago that beta-carotene, another vegetable
antioxidant, was thought to protect against cancer. Then a clinical
trial was started to see if it really did. The study was halted early
after it was discovered that those consuming more beta-carotene had
increased cancer risk.
At this point, the entire “antioxidant” theory of cancer prevention
is faring poorly. Just this month the U.S. Food and Drug Administration
told tomato product manufacturers that they can no longer proclaim on
food labels that lycopene, another high-profile tomato “antioxidant,”
might reduce the risk of prostate or other cancers. The agency reviewed
81 studies supposedly supporting this claim and found “no credible
evidence supporting a relationship between lycopene consumption, either
as a food ingredient, a component of food, or as a dietary supplement,
and any of the cancers evaluated in the studies.”
What about the claim that antioxidants lower blood pressure, and,
thus, the risk of heart disease and stroke? Scores of media reports
treat this claim as if it was irrefutable. Yet here, too, the science
is far less clear than the media portrays.
Studies have shown that in people with high blood pressure, a diet
rich in fruits and vegetables lowers blood pressure slightly (3-4 mm of
Hg). Just precisely what in that diet is responsible for this slight
drop has been the big question, with many assuming a role for
flavonoids and other antioxidants. But new research published last
December in the New England Journal of Medicine indicates it
could be the nitrates, not the antioxidants, which lower blood
pressure. Daily nitrate supplements equal to the amount found in a
quarter pound of spinach lowered blood pressure in study subjects by an
amount equal to the drop seen in the dietary studies. If it is nitrates
that lower blood pressure, not the “antioxidants”, conventional
vegetables are the healthier option. Studies repeatedly show that
regular, non-organic vegetables have between 10-50 percent more
nitrates than organic ones.
So if you’re worried about protecting yourself from cancer and high
blood pressure, the science says you’d be best off eating a balanced
diet that includes a variety of fruits and vegetables and forgetting
the organic hype and high prices.
ALEX A. AVERY is the Director of Research at the Hudson Institute’s Center for Global Food Issues and the author of The Truth About Organic Foods. Dennis T. Avery is a senior fellow at Hudson. Readers may contact them at The Center for Global Food Issues (www.cgfi.org) Post Office Box 202, Churchville, VA 24421.
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