Monday, May 28, 2012

How Super Is This Fruit? Part 2

A few weeks ago, I posted an article about the flaws inherent in the 'superfoods' craze - what defines a food as being super, who gets to decide that, and whether it's all just marketing anyway - and this week I'm following up with an article from the Wall Street Journal on a related topic, ORAC value. For those unfamiliar with the ORAC value, ORAC stands for Oxygen Radical Absorbance Capacity, and the ORAC value is used as a measure of how potent of an antioxidant a given substance is. The measure is often used in marketing supplements and superfoods as a way to make the product stand out. Unfortunately, the ORAC measure has significant limitations. The ORAC test only measures a plant's ability to absorb one kind of oxygen radical (oxygen radicals are unstable, disease-causing compounts quenched by antioxidants), which leads to some skewing of results towards certain types of antioxidants but not others. Additionally, a substance's ability to perform in a lab test doesn't necessarily translate to it's ability to prevent disease - many compounds that are excellent antioxidants are too large to be absorbed by the body, while others might perform well in the lab, but struggle to find an effective place within the body's complicated biochemistry. To be sure, antioxidants are important, but we don't need lab values to tell us what to eat - thousands of year of human history have produced antioxidant rich, health-promoting diets in countries all over the world, and it's just a matter of paying attention to those traditional diets.