> In recent years we have seen that the results of similar “observational” studies were disproved when subjected to a “randomized controlled trial”—the standard bearer of scientific proof. A good example of this is female hormone replacement. For decades it was believed that female hormone replacement was beneficial. But a randomized controlled trial, called the Women’s Health Initiative, demonstrated that the exact opposite was true. The study was stopped in 2002 because women taking the study pills of estrogen plus progestin were developing heart disease and breast cancer at increased rates compared to those taking the placebo or inactive pills."
http://www.kevinmd.com/blog/2011/01/red-wine-good-heart-brai...