Whether you have a reaction to dairy products–and how dramatic that action may be–depends on how often you eat foods made from milk. Guzzle yogurt and milk shakes around the clock, and you’ll probably get upset stomach. Go easy and have just a few bites of cheese, and you should be completely in the clear. “Research indicates that people who are lactose intolerant can consume half a cup of milk without a problem,” says a nutritionist. “If you watch your quantities and make sure you eat dairy products along with other foods, this should make them easier to digest.”
When your body doesn’t produce sufficient amounts of lactase, the enzyme that breaks down a milk sugar called lactose; this gives you “lactose intolerance”–bloating and stomach upset that can take all the fun out of ice cream. Lactose intolerance afflicts 70 percent of the world’s population, including 50 million Americans. It is especially prevalent among people of African, Asian, Jewish and Hispanic descent, and tends to develop later in life, after your body has weaned itself of the milk you needed as a baby. Lactose intolerance is not to be confused with an allergy to milk–a more severe reaction that fires up your immune system, clogs up your windpipe, and makes hives erupt on your skin.
If reducing your consumption of milk products doesn’t help, there are other tricks you can try. Buy Lactaid, a special type of milk for people who are lactose intolerant. Instead of drinking milk, reach for yogurt or cheese, which may be easier to digest because the bacteria in yogurt and the heat used in cheese production both break down lactose to some degree. Experts also recommend steering clear of milk if your stomach is already upset. “The environment of the intestine makes a big difference,” explains one health expert. “The enzymes that break down lactose are right on the surface cells of the intestine, so if you have any diarrhea, they are among the first enzymes to get lost and flushed away. “If you have tummy trouble, avoid milk at all costs: It’s the last thing that will do your body good.