ORAC – Oxygen Radical Absorbance CapacityORAC, an acronym for oxygen radical absorbance capacity, is the measurement of a compounds' power to neutralize free radicals. The higher the value, the stronger the compounds' capacity and the greater its' ability to prevent free radical damage at the cellular level. It was developed at the National Institute on Aging in Baltimore, Maryland. A wide variety of foods have been tested using this methodology, with certain berries and legumes rated very highly. Correlation between the high antioxidant capacity of fruits and vegetables, and the positive impact of diets high in fruits and vegetables, plays an important role in the free-radical theory of aging. Method The assay measures the oxidative degradation of fluorescein after being mixed with peroxyl radical. The reaction alone is compared to the reaction in the presence of a standard antioxidant (trolox, a vitamin E analogue) and the antioxidant sample being tested. The fluorescent intensity of the fluorescein decreases as it gets oxidized, and measurements of this intensity are taken every minute for 35 minutes after the addition of the oxidant. The oxidative decay of fluorescein is less rapid in the presence of antioxidants. A graph of the decay curve (fluorescein intensity vs. time) is generated and the area under the curve is calculated. Different concentrations of trolox are used to make a standard curve, and test samples are compared to this. Final results for test samples are published as “trolox equivalents” or TE. One benefit of using the ORAC method to test a substance’s antioxidant capacity is that it takes into account samples with and without lag phases of their antioxidant capacities. This is especially beneficial when measuring foods and supplements that contain complex ingredients with various slow and fast acting antioxidants, as well as ingredients with combined effects that cannot be pre-calculated. Comparisons of ORAC values When comparing ORAC data, care must be taken to ensure that the units and food being compared are similar. Some evaluations will compare ORAC units per grams dry weight, others will evaluate ORAC units' wet weight and still others will look at ORAC units/serving. Under each evaluation, different foods can appear to have higher values. Although a raisin has no more antioxidant potential than the grape from which it was dried, raisins will appear to have a much higher value per gram wet weight than grapes due to their reduced water content. Likewise, watermelons large water content can make it appear as though they are very low in antioxidants. To say then that chocolate has “more antioxidant” potential than blueberries is tenuous at best. While ounce per ounce chocolate may have a higher value, on the comparison of dry weight, we see blueberries have a higher value. Additionally, considering the value per calorie could be of some utility, as understanding just how much antioxidizing potential one could incorporate from a product into one’s diet would determine the real utility of the product. Recently, a number of health food companies have capitalized on the ORAC rating, with dozens selling concentrated supplements that they claim to be “the number one ORAC product”. Most of these values have never been published in the scientific literature so are difficult to evaluate. It is not known whether such values are accurate or how absorbable and functional these concentrated antioxidants are in the human body. The Antioxidant Power of Vemma™
††Comparisons based on independent lab tests conducted in April 2006 (Lot #018614), May 2006 (Lot #FJ41315203A), June 2006 (Lot #00438326, #T0a and #5060982). The product and company names are registered trademarks of their respective companies. Return from ORAC Value to All-Day-Energy
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