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  • From: "Kevin Ancell" <kancell AT goodearthgardens.com>
  • To: "Market Farming" <market-farming AT lists.ibiblio.org>
  • Subject: [Market-farming] Are organic foods really better for us?
  • Date: Wed, 5 Mar 2003 19:03:46 -0800

Sustainable fruit shows marked rise in antioxidants
05/03/03 - Are organic foods really better for us? The debate continues this
week with new findings from food scientists in the US that suggest fruits
and vegetables grown organically have higher levels of antioxidants than
conventionally grown foods thanks to the plants' natural defence system.

Science remains undecided on whether organic foods are of greater benefit to
our bodies than conventional foods. But following her research on the amount
of antioxidants found in corn, strawberries and a type of blackberry called
a marionberry, Alyson Mitchell, a food scientist at the University of
California in the US, claims that the results weigh heavily in organic's
favour.
Her research suggests that pesticides and herbicides actually thwart the
production of phenolics - chemicals that act as a plant's natural defence
and are also beneficial to our health. Fertilisers, however, seem to boost
the levels of anti-cancer compounds.

Flavonoids are phenolic compounds that have potent antioxidant activity.
Many are produced in plants in response to environmental stressors, such as
insects or competing plants.

"If an aphid is nibbling on a leaf, the plant produces phenolics to defend
itself," said Mitchell. "Bitter or harsh phenolics guard the plant against
these pests."
The need for these natural safeguards decreases with the use of herbicides
and pesticides in conventional agriculture. This decrease is reflected in
the total amount of antioxidants the plants produce.

"This helps explain why the level of antioxidants is so much higher in
organically grown food," added Dr. Mitchell.

"By synthetically protecting the produce from these pests, we decrease their
need to produce antioxidants. It suggests that maybe we are doing something
to our food inadvertently."

Mitchell's investigation involved the total antioxidants found in foods
grown organically (using no herbicides, pesticides or fertilizers) to foods
grown sustainably (in this study fertilizers but no herbicides or pesticides
were used) and conventionally (using synthetic chemicals to protect the
plants and increase yield).
The results showed a significant increase in antioxidants in organic and
sustainably grown foods versus conventionally grown foods. The levels of
antioxidants in sustainably grown corn were 58.5 per cent higher than
conventionally grown corn. Organically and sustainably grown marionberries
had approximately 50 per cent more antioxidants than conventionally grown
berries. Sustainably and organically grown strawberries showed about 19 per
cent more antioxidants than conventionally grown strawberries.

Of particular interest is the finding that antioxidant levels were highest
overall in sustainably grown produce, indicating that a combination of
organic and conventional practices yields the highest levels of
antioxidants.

"This may reflect the balance between adequate nutrition in the form of
fertilisers and external pest pressures because of the lack of pesticides
and herbicides," explained Mitchell.

Full findings appear in the 26 February print edition of the Journal of
Agricultural and Food Chemistry.



  • [Market-farming] Are organic foods really better for us?, Kevin Ancell, 03/05/2003

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