During pasteurization, milk is heated to high temperatures (>161°F) then rapidly cooled to kill harmful bacteria, including salmonella, E.coli 0157:H7 and listeria. While raw-milk enthusiasts claim heating milk destroys its natural enzymes and beneficial bacteria, studies show that the nutritional differences between pasteurized and raw milk are slight. What’s more, public health experts warn that drinking raw milk is like playing Russian roulette. In fact, the Centers for Disease Control and Prevention reported that raw milk accounted for 1,007 illnesses and two deaths between 1998 and 2005. And when USDA scientists collected raw milk samples from 861 farms in 21 states, nearly a quarter of them contained bacteria linked to human illness, including 5 percent that tested positive for Listeria—a bacterium that results in a foodborne illness, listeriosis, and has a 30 percent mortality rate.