What are ORAC Values?
Are ORAC values a better way to measure the total antioxidant capacity of foods or just another marketing ploy? Learn what these numbers mean for your health.
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If you spend a lot of time reading about nutrition (which I do), it starts to feel as if we're all in some sort of contest to see who can eat the most antioxidants. Those who are interested in (dare I say, obsessed with?) antioxidant nutrition will often talk about a food's ORAC value. As in, "Wild blueberries have an ORAC value of 9,621, while regular blueberries only have an ORAC of 4,669!" What on earth are these people talking about?
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ORAC stands for Oxygen Radical Absorbance Capacity. It's a lab test that attempts to quantify the "total antioxidant capacity" (TAC) of a food by placing a sample of the food in a test tube, along with certain molecules that generate free radical activity and certain other molecules that are vulnerable to oxidation . After a while, they measure how well the sample protected the vulnerable molecules from oxidation by the free radicals. The less free radical damage there is, the higher the antioxidant capacity of the test substance. There are actually a handful of different tests designed to measure total antioxidant capacity in this way, but the ORAC is probably the best known and most popular.
The nice thing about this method is that it measures the antioxidant activity of a food rather than the levels of specific nutrients, such as vitamin C or E. After all, there are thousands of unique antioxidant compounds in plants, most of which we haven’t even discovered yet. There’s no way we could measure them all individually. This approach would also capture any synergistic effects between the various nutrients—ways in which nutrients are more effective in combination than they are individually.
Where to Find ORAC Values
The lab that developed one of these tests has measured the ORAC values in hundreds of foods and spices and published those values in a database, which you can find online. Some of the results might surprise you. For example, who would have thought that whole grain bread has a higher antioxidant capacity than bean sprouts? Or that kidney beans pack four times the antioxidant punch of broccoli?
Some of the results are a bit misleading. For example, you’ll find spices like cinnamon and cloves with 6-digit ORAC values. However, all of the ORAC scores refer to 100-gram servings. Once you convert these into the amounts you’d typically consume in a meal, cinnamon and cloves are comparable to the antioxidant activity of small apple or pear.
Once this database was published, it was inevitable that people (as well as marketers) would start competing to see who could rack up the highest score.
See also: Superfruits