jokolungo
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salam
ko baca lah kat sini. boleh faham kan..
http:
//skeptoid.com/episodes/4086
aku kopipes skit
Dr. Stephen Barrett sums it up quite aptly in an article about antioxidants (which also lists this and many other clinical trials if you want to see for yourself):
"There is widespread scientific agreement that eating adequate amounts of fruits and vegetables can help lower the incidence of cardiovascular disease and certain cancers. With respect to antioxidants and other phytochemicals, the key question is whether supplementation has been proven to do more good than harm. So far, the answer is no, which is why the FDA will not permit any of these substances to be labeled or marketed with claims that they can prevent disease."
So now let's move on to our final question: Do these superfruit juices really contain significant amounts of antioxidants? They better, because they base their entire marketing campaign around this claim specifically.
Choice, the publication of the Australian Consumers Association, undertook a major study to answer this question in 2007. They bought virtually every superfruit juice that's commercially available. In their labs, they tested all of them for their total antioxidant capacity using the oxygen radical absorbance capacity assay test, laying out their methodology in detail — which you'll notice the promoters of these products never do.
As a baseline, Choice measured the total antioxidant capacity, or TAC, of a common apple — a Red Delicious Apple, to be precise — and got a reading of 5900. This number was then compared to the TAC measured from a daily serving of each superfruit juice.
* The first type of superfruit juice tested was goji, a berry from Asia also known as the wolfberry. Servings of four different goji-based superfruit juices were found to have TAC measurements ranging from 570 to 2,025 for a product that is a 100% purée of the berry, in other words, from 10% to 34% the TAC of a common apple.
* Next, they tested two brands of mangosteen superfruit juices. Mangosteen is claimed to have double the antioxidant capacity of goji. The results? Two two juices came in at 1,020 and 1,710, or 17% and 29% of the TAC of a common apple.
* Next, they tested two brands of noni superfruit juices. Noni comes from Polynesia, and is frequently used in Hawaiian traditional medicine. The two brands measured 540 and 525, each about 9% the TAC of a common apple. In other words, a $7 cup of noni juice contains as much antioxidants as a thin 5¢ slice of apple.
* Finally, Choice put açai to the test. The açai is a small purple berry from the Amazon, and Oprah calls it the "#1 food for anti-aging." Açai is the headliner ingredient in MonaVie, but since they do not disclose their formula, the percentage is unknown. Choice tested a similar product from RioLife containing 14% açai pulp. It measured almost as well as the best goji juice, with a TAC of 1,800, or about 31% as much as a common apple.
Choice also added several more common fruits to the mix. A single navel orange was found to have a TAC of 2,540. A cup of strawberries has 5,938. A cup of raspberries has a TAC of 6,058. And the overall winner was a cup of cultivated blueberries, with a total antioxidant capacity of 9,019.
But how can this be? Choice magazine found that the marketing literature says that goji berries have ten times, and açai berries six times, the antioxidant capacity of blueberries. Well, this might well be true. The difference is due to the fact that you're drinking a juice made from the fruit, you're not eating the whole fruit itself. For example, the mangosteen fruit has a huge amount of antioxidants and other nutrients. However, it's all contained within the inedible rind. The edible pulp of the fruit has only a negligible amount of either. This is how it's possible for the marketing claim to be, well, accurate if misleading; but the product itself to be devoid of the claimed benefits.
Superfruit juices may be good sources of antioxidants compared to, say, spaghetti or a cheeseburger; but if you want antioxidants, you'll get far more of them for about 1/100th the price by simply eating common fruit from the supermarket
