Antioxidant Power of Natural Product Supplements Highly Variable
ARS News Service
Agricultural Research Service, USDA
Judy McBride, (301) 504-1628, email@example.com
August 9, 1999
Chances are you'll get more protection from eating fresh fruits and
vegetables than from taking natural product supplements claiming to be
potent antioxidants. That's according to analyses of 46 commercial
preparations by researchers with the Agricultural Research Service, the
chief scientific agency of the U.S. Department of Agriculture.
The total antioxidant capacity of 40 berry-based supplements ranged from 16
to 3985 ORAC units--a 249-fold difference. The supplements tested included
bilberry, cranberry, chokeberry and elderberry extracts. Six other
antioxidant products with grape seed or pine bark extracts or pycnogenol®
ranged from 16 to 8392 ORAC units--a 525-fold difference.
ORAC--short for oxygen radical absorbance capacity--measures the ability of
a chemical or biological sample to disarm oxygen free radicals, which can
precipitate a cascade of oxidative damage in body cells. Theory holds that
such damage is behind heart disease, cancer and other diseases of aging. So
antioxidant supplements are gaining popularity.
The results remind consumers that there are no industry standards for the
antioxidant capacity of natural product supplements and thus little
assurance of a high quality product, according to ARS chemists Ron Prior and
Guohua Cao at the USDA Human Nutrition Research Center on Aging at Tufts in
Prior and Cao report their findings in the summer issue of the Journal of
the American Nutraceutical Association. An abstract of the article will
appear on the Web at:
The researchers point out that a single serving of fresh or freshly cooked
fruits or vegetables supplies an average of 300 to 400 ORAC units. Many
fruits and vegetables--such as berries, plums, oranges, leafy greens and
beets--provide much higher antioxidant levels. By contrast 28 of the 40
berry extracts tested and one of the six other products wouldn't provide 300
ORAC units in a day's suggested intake.
Scientific contacts: Ronald L. Prior, phone (617) 556-3311, or Guohua Cao,
phone (617) 556-3141, USDA Human Nutrition Research Center on Aging at Tufts
University, Boston, Mass., fax (617) 556-3299, firstname.lastname@example.org,
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