To Your Health
Is mangosteen really a more powerful antioxidant than blueberries?
A. Mangosteen, an exotic tropical fruit, not to be confused with the familiar mango that we can find in our supermarkets, is used in Asian medicine to treat diarrhea and some other maladies. It has recently been touted as the most potent available food source of antioxidants according to the USDA test of antioxidant power known as ORAC, short for oxygen radical absorbance capacity. Compared to blueberries with an ORAC value of 2,400 units per 100 grams, marketers of mangosteen juice claim that it has 17,000 units per 100 grams.
Studies at Tufts University suggest that consuming fruits and vegetables with a high ORAC value may help slow the aging process. A large number of fruits and vegetables qualify as "high ORAC value" foods with scores that average 900, and blueberries are near the top of the list. Prunes and raisins actually have higher scores but only because they are dried. Plums and grapes have ORAC scores about one-third that of blueberries.
The ORAC value reflects the strength and duration of a food's antioxidant protection ability as a single number. The ORAC number is important because free radical damage accelerates the aging process and increases the risk of certain types of cancer, coronary heart disease, and many other health problems.
A major drawback of the ORAC test is that many chemicals behave entirely differently in our bodies compared to their behavior in a test tube. A high ORAC number (in a test tube) does not guarantee that your body can absorb and utilize the antioxidants that produce the high ORAC score.
Also, it is not yet known whether the use of such a high-ORAC food as mangosteen has health advantages. In a study comparing nine common fruits (pear, apple, orange, grape, peach, plum, kiwi, melon, and watermelon), with the exception of pears, all these fruits suppressed the generation of free radicals in the blood of study subjects for about 90 minutes (see Journal of Medicinal Foods, spring 2005, pp. 41-46). These results suggest that fruit juices reduce damage from oxidative stress as expected but that the effect is relatively short-lived. This is quite reasonable, since the body actually uses free radicals to defend against invading bacteria. If that defense were suppressed for an extended period of time, the body would be more vulnerable to life-threatening infections.
Antioxidant activity in the body is tightly controlled, and Dr. Ronald Prior of the U.S. Department of Agriculture Research Service estimates that the ideal intake is 3,000 to 5,000 ORAC units per day, and higher amounts may have no added benefits. This translates to one-to-three servings per meal of high ORAC fruits and vegetables, an amount any of us could manage.
Entrepreneurs are always on the lookout for natural medicines, especially cancer cures. Mangosteen has recently joined a long list of natural compounds that may have anti-cancer activity. An extract of mangosteen rind inhibits the reproduction of cultured breast cancer cells and increases the rate of apoptosis or "cell suicide." It is a very long way from an observation such as this to a "cancer cure," but experiments such as this certainly increase the sales of mangosteen.