Pesticide and Environmental Update
Mexican Oregano Tops for Antioxidant Protection
Herbs Can Spice Up Your Antioxidant Protection
Rosalie Bliss
Ounce for ounce, many herbs used to flavor our foods have more
antioxidant power than berries, fruits and vegetables, according to a recent Agricultural Research Service study. Previous studies of animals and
of human blood have shown that foods that score
high in antioxidant capacity may protect cells and their components from
oxidative damage. The thesis that oxidative damage
culminates in many of the maladies of aging is well accepted in the health community.
Herbs are known to be good sources of antioxidants, but their potency can
vary depending on species and growing conditions. So researchers at the ARS Fruit Laboratory in Beltsville, Md., evaluated a variety of fresh
culinary and medicinal herbs grown under the same
environmental conditions at the same location, the
ARS National Arboretum in Washington, D.C. ARS plant physiologist Shiow Wang
and visiting scientist Wei Zheng from the Institute of Environmental Science in Zhejing, China, put 27 culinary herbs and 12 medicinal herbs to the antioxidant test. Known as ORAC for
short, the test measures the ability of a sample
to disarm oxidizing compounds, which our bodies naturally generate as a
byproduct of metabolism.
Three different types of oregano- Mexican,
Italian and Greek mountain--scored highest in antioxidant activity. Their
activity was stronger than that of vitamin E and comparable to the food
preservative BHA against fat oxidation, the
researchers reported in the November 2001 issue of the Journal of
Agricultural and Food Chemistry.
Several other culinary herbs--among them rose geranium, sweet bay, dill,
purple amaranth and winter savory--also showed strong antioxidant activity. But it was about one-half to one-third as potent as that of the
oreganos. The medicinal herbs generally scored lower in antioxidant
activity, suggestingthat their health benefits
mostly stem from other functions in the body.
According to Wang, antioxidant activity of these herbs may vary considerably, depending on where they are grown. But their rankings would
tend to hold up in other environments because of characteristic compounds
in each species. The oreganos, for instance, had high levels of the potent antioxidant rosmarinic acid.
The highest scorer in this study, Mexican oregano (Poliomintha longiflora), is used in traditional Mexican and Southwest recipes. Its flavor is a bit stronger than Italian oregano (Origanum x majoricum), used to season
meats, egg dishes, soups and vegetables. Greek mountain oregano (Origanum
vulgare ssp.hirtum), had the third highest score.
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