ORAC- Oxygen Radical Absorption Capacity

ORAC- Oxygen Radical Absorption Capacity

Written By: Peter Kopko

A new method of measuring the antioxidant capacities of different foods was developed by scientists at the NIH . This method measures the oxidative degradation of a molecule that has been made to fluoresce after it has been mixed with free radical generators. In more simple terms, a food substance like a carrot has a special molecule added to it that has been engineered to glow. The amount of time and intensity that the molecule will glow is determined by how much and how fast it is damaged by adding a free radical. This is known as the decay curve , florescent intensity vs. time. The only thing that will slow down the destruction of the glowing molecule is if it is protected from the oxidative damage of the free radical by naturally occurring antioxidants in the food substance.

The longer the fluorescent molecule glows the more antioxidant present in the food substance. Correlation between the high antioxidant capacity of fruits and vegetables, and the positive impact of diets high in fruits and vegetables, is believed to play an important role in the free-radical theory of aging.

Quite an ingenious method. And what did they find? That certain spices, herbs, legumes and berries rated very highly.

Here is a partial list from the Department of Agriculture:

USDA data on foods with high levels of antioxidant phytochemicals