Test Could Identify Antioxidant Properties of Fruits and Vegetables
January 02, 2008
Antioxidants are a wide range of compounds that interfere with the damage done to cells by free radicals -- charged particles that are produced by radiation and chemicals. Fruits and vegetables are loaded with antioxidants, which range from chemicals such as the resveratrol found in red wine, to the anthocyanins that make strawberries red and blueberries blue and vitamins A, C and E. Prunes, renowned for their more immediate health effects, may also be the best defense against cancer and heart disease.
Spinach, on the other hand, may be the "brain food" needed to avoid memory loss and Alzheimer's disease. Working on behalf of the U.S. Department of Agriculture, the Tufts team has come up with a test to identify the antioxidant properties of fruits and vegetables, and they have ranked some in order of their levels of antioxidants. The test showed prunes, popular for relieving constipation, have far more antioxidants than anything else, followed by raisins, blueberries and blackberries. Kale comes next, then strawberries and spinach.
There's a definite synergistic action between a lot of these compounds. I've stayed away from isolating any one compound. The mixture is going to have more of a benefit than any one component. The test, known as oxygen radical absorbance capacity or ORAC, measures the ability of the blood, or any other substance such as food, to subdue free radicals. It is impossible to separate out each antioxidant in food. The test looks at the ability of a food overall to scavenge up the free radicals.
Women given 10 ounces of fresh, raw spinach saw their ORAC score go up even more than when they took 1,250 milligrams of vitamin C. An eight-ounce serving of strawberries was less effective than the vitamin C but had a stronger impact than 9.6 ounces -- about three glasses -- of red wine. In rats, a daily serving of spinach prevented the memory loss and slowdown in learning capacity usually seen as the animals age. Rats given spinach or vitamin E from the age of six months were less likely to forget where things were as they got older than rats given nothing extra, or rats that got strawberries.
Dr. Mercola's Comment:
It will be interesting to see if this assay gains widespread acceptance. I would also caution those who may have carbohydrate excess that it the macronutrient composition of the food is overall more important than a few of these antioxidants. Controlling insulin levels is FAR MORE important than making sure one has antioxidants from fruits. Fruits certainly have some very beneficial properties but if you are eating to many grains and then have fruits on top of them, or worse yet fruit juice, your overall health will decline, not improve.