If you're lactose intolerant or get an upset stomach after a glass of milk, you may want to try dairy products from a different kind of cow. Increasing research suggests Holstein cows, commonly used by American dairy farms, produce a milk protein called A1 that may be more difficult to digest. Some who have studied A1, like Dr. Richard Deth of Northeastern University, have even found a link between A1 and autism – and that's not all. "Studies from others have indicated a link between A1 milk and autoimmune diseases such as type-1 diabetes and cardiovascular disease," says Deth.

A1 is less prevalent in Jersey cows, Guernseys, and the Normande, all which primarily produce a milk protein called A2 that studies show is more digestible and does not increase the risk of certain diseases. Want to try A2 milk? You can wait for the New Zealand-based dairy brand A2C to bring its popular A2-based milk to the U.S. later this year. Or look for milk from small dairy farms that advertise they use Jerseys, Guernseys, or Normandes on their product or website.