Why do they drink milk in the winners circle at the Indy 500?

The ONLY race where milk is drunk afterwards is the Indianapolis 500. It is a tradition that started with the first 500. If you watch European Formula racing, you will see them take a sip or two of champagne, NASCAR drivers do Soft Drinks, Gatorade, water, or even beer. According to the IRL, the milk tradition at the Indy 500 was started in 1936 when the winner, who drank buttermilk on hot days, was photographed drinking buttermilk in Victory Lane. The head of the local dairy saw the picture and talked the track into continuing it. It's a nice tradition.