Red wine is a potent source of antidiabetic compounds – but they might not get past your gut. The finding is sure to enliven the ongoing debate over the drink's health benefits. Alois Jungbauer and colleagues at the University of Natural Resources and Life Sciences in Vienna, Austria, tested 10 reds and two whites to find out how strongly the wines bound to a protein called PPAR-gamma, which is targeted by the antidiabetic drug rosiglitazone. (This drug is marketed under the brand name Avandia and, while still available in the US, has been withdrawn in Europe because of fears over side effects.)