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TechnoratiRecent claims about the Acai Berry Diet, “super-antioxidant foods” and ORAC values have led to confusion about the benefits, sources and role of antioxidants.
Why are antioxidants so important? Where do we get them? And what exactly is an ORAC? Here are the basics to help clear up the confusion.
Antioxidants
Antioxidants are substances or nutrients in our foods which can prevent or slow the oxidative damage to our body. When our body cells use oxygen, they naturally produce by-products called free radicals which can cause damage. Free radicals may also be further produced by improper diet, strenuous exercise, tobacco, alcohol, stress and polluted air.
Many chronic and degenerative diseases, such as cancer, heart disease, macular degeneration, diabetes, Alzheimer’s disease and Parkinson’s, are thought to be caused, in part, by oxidative stress from free radicals. Oxidative stress has also been linked to the process of aging.
The only way to combat free radicals is to neutralize them with antioxidants. Antioxidants act as "free radical scavengers" which prevent and repair damage done by these free radicals. Antioxidants may also enhance immune defense, lowering the risk of infection.
Though nature provides the body with some antioxidants, there is always a need to constantly replenish our antioxidant supply each day.
Sources of Antioxidants
Foods such as fruits, nuts, and vegetables have long been considered to be excellent sources of antioxidants. Common antioxidants found in food are phytochemicals (such flavonoids/polyphenols), lycopene and lutein.
A number of minerals and vitamins have a role as dietary antioxidants in addition to their other biological functions. These include vitamin A and carotenoids, vitamin C, vitamin E (including tocopherols and tocotrienols), and selenium. There are also vitamin-like antioxidant sources such as CoQ10 and glutathione.
ORAC values
ORAC stands for Oxygen Radical Absorbance Capacity, and rates foods according to their antioxidant content. The higher the ORAC score, the greater the food's antioxidant capacity. ORAC tests are often used to compare the antioxidant activities of different foods (fruits, vegetables, juices, wines, etc
Such comparisons can be valuable, but they do carry limitations. First, ORAC analyses are not extremely precise. When one food is tested multiple times in a given laboratory, ORAC rating score can vary 10-15% from one sample to the next. Second, different laboratories conduct ORAC testing in different ways, and often produce very different results. Third, different orange juices, for example, that were manufactured and diluted in different ways, and stored under different conditions, can actually have very different antioxidant activities, such that it is difficult to assign a meaningful ORAC score to orange juice in general. And lastly, product comparisons may not be for equal amounts; some are based on servings, others on wet weight, still others on dry weight. This can, for instance, lead to raisins having a much higher ORAC value than the grapes from which they came.
Foods that consistently score high on the ORAC ratings are spices (cinnamon, turmeric, oregano, cloves), berries (wild blueberries, tart cherries, elderberries, chokeberries, cranberries), legumes (red, pinto and kidney beans), grains (sorghum, rice bran, flax), chocolate (cocoa powder, baking chocolate), nuts (pecans, walnuts, hazelnuts, pistachios). Common fruits such as apples, apricots, plums, cherries, pears, as well as greens such as artichoke hearts, broccoli, asparagus and cabbage, also are near the top of the list. Green tea and dark juices have high ORAC values as well. Continue »
