I'm often asked about Açaí, the latest miracle fruit that is supposed to cure whatever ails you. If this is a miracle, it's one that must be enjoyed by the company that makes MonaVie brand Açaí, which sells for about $40 a bottle. I had heard about Açaí and was not overly impressed. But then I got an e-mail from a MonaVie enthusiast who was so convinced of its benefits that he sent me the research.

Here's one of the studies. It looks formidable but its conclusions are simple. In translation: MonaVie contains antioxidants. The antioxidants in MonaVie act like antioxidants in the test tube and in the body, and they work better than potato starch, which has no antioxidants. Why am I not surprised? This is a study sponsored by the manufacturer.

You can read about this study and the rest of fuss over this juice in the March 12 New York Times. It's in the Style Section (where else?). The bottom line: all juices have antioxidants and most are a lot cheaper than MonaVie.

As for weight-loss claims: This month's Nutrition Action Healthletter explains how to analyze Internet advertising, using Açaí as an example of truth-bending.