
Antioxidant Power of Natural Product
Supplements Highly VariableBy Judy McBride August 9, 1999Chances 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 Boston, Mass. 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: http://www.americanutra.com 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 contact: Ronald L. Prior, phone (617) 556-3311, or Guohua
Cao, phone (617) 556-3141, USDA Human
Nutrition Research Center on Aging at Tufts, Boston, Mass., fax (617)
556-3299, [email protected],
[email protected]. U.S. Department of Agriculture | |