Just out in New Scientist: If you're frying or grilling a steak, you'd do well to marinate it in beer for a few hours beforehand. That's because cooking food increases levels of cancer-causing compounds called heterocyclic amines (HAs). Fried and grilled meat are particularly high in these compounds, because fiery temperatures convert the sugars and amino acids in muscle tissue into HAs.
Beer contains more water-retaining sugars than wine and Ferreira says that may hinder the transport of water-soluble molecules to the steak's surface, where high heat converts them into HAs. Tasters also preferred the smell, taste and appearance of beer-marinated steak.
Bear in mind that this effect applies only when the meat to be cooked is immersed in beer for a period of several hours; the reverse is not true: immersing yourself in beer for a period of several hours prior to grilling will not only have no effect upon the production of HAs, but is likely to increase the risks associated with grilling.