Antioxidants and Free Radicals By Dr. Cathy Sabota, Horticulture Specialist

The Alabama Cooperative Extension System at Alabama A&M University held its 2006 Urban-Rural Interface Conference in April that focused on functional foods. Here is some information on antioxidants and free radicals that was presented at that event.

The presentation by Dr. Ronald Prior of the Arkansas Children's Hospital Research Center provided significant information on what we should be eating and why.

Free radicals are a part of life and are described as the chemical reaction of ions or atoms in the body that destroys cells. We consume 6 to 11 pounds of oxygen every day, of which 2.8 percent is not completely reduced and forms free radicals. As much as five pounds of peroxide may be produced in our body every year. If excessive free radicals remain in the body without the consumption of enough antioxidants, then oxidative stress may occur. Oxidative stress can contribute to aging, cancer, Parkinson's disease, radioactive damage, arthritis, diabetes, frostbite, inflammation, and infection.

To reduce the risk of oxidative stress, it is important to include sufficient high-antioxidant foods in our diets. ORAC, short for Oxygen Radical Absorbance Capacity, is a test tube analysis that measures the total antioxidant power of foods and other chemical substances (McBride, 1999). The average antioxidant level of vegetables is 1.37 ORAC per serving with artichokes having the highest level at about 8 ORAC per serving. Avocados, potatoes, broccoli, raab, peas, and asparagus score above the 1.37 ORAC average for vegetables. Fruits average 3.56 ORAC per serving with wild blueberries at more than 13 ORAC. Cultivated blueberries and cranberries score about 9 ORAC per serving, while blackberries, raspberries, strawberries, cherries, black plums, and apples score above the 3.56 ORAC fruit average per serving (Prior, 2006).

If you prefer to drink your antioxidants, the most potent fruit juices are blueberry, plum, red grape, and cranberry. However, when consuming juices, be aware of the sugar content and consume with caution. If you prefer to chew your antioxidants, granola, toasted oatmeal squares, and oat bran provide 1.0 ORAC or more antioxidants per serving. Pecans, walnuts, hazelnuts, and pistachios contain more than 2.0 ORAC per serving.

The average intake of antioxidants per day in the United States from 2.5 servings of fruits and vegetable is 4.6 to 5.5 ORAC. The estimated ORAC intake from 9 high-ORAC value servings of cereal, fruits, and vegetables per day is 20.7 ORAC. Depending on energy output, smoking, drugs, and other factors, you should consume between 4.4 and 13.3 ORAC of antioxidants per day. The more active you are the higher the requirement, as is true of smoking or other health conditions.

If you would like more information on Dr. Prior's presentation or to purchase a copy of the conference video, please contact Dr. Cathy Sabota at Catherine.sabota@email.aamu.edu or call 256.372.4257.

References
McBride, Judy. (February 8, 1999). High-orac foods may slow aging. News and Events. United States Department of Agriculture.

Prior, Ronald. (2006). Antioxidants, free radicals and health: Translating the science into dietary recommendations. [videotape] (Available from Alabama Cooperative Extension System, Alabama A&M University, Normal, AL 35762).

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