Your Practical Guide to Lactose Intolerance

You scream for ice cream — but every time you indulge in a cone, your stomach answers back to you. The problem might be that your body can’t process lactose.

A diagnosis of lactose intolerance can be disconcerting. But it doesn’t necessarily mean you have to say goodbye to all dairy products, says gastroenterologist Christine Lee, MD. Part of dealing with the condition is knowing your triggers.

Below, Dr. Lee explains why lactose intolerance exists, how it’s diagnosed and what you can do to manage it.

Diagnosing lactose intolerance

Lactose is a carbohydrate in dairy products. Lactase is an enzyme needed to digest lactose in the small intestine.

But if your body doesn’t have enough lactase, undigested lactose can cause GI symptoms in the intestines, mainly pain and diarrhea, Dr. Lee says. The adult version of lactose intolerance can come on as you age with decrease lactase activity.

A hydrogen breath test can determine if you are lactose intolerant.

In this test, patients receive 25 grams of lactose to drink, and their breath is measured over time. If lactose passes into the colon intact, the levels of hydrogen in the breath will rise, indicating a case of lactose intolerance, Dr. Lee says.

There’s a simple method, too. Stop eating lactose-containing foods, and keep a food diary to monitor whether symptoms go away.

What foods are the culprits?

Milk, cream cheese, ice cream, sour cream, cottage cheese and certain soft cheeses are especially high in lactose.

Not all dairy is the same, though. For instance, yogurt contains bacteria that break down lactose. That doesn’t mean it’s lactose-free, though.

Be careful about eating foods that contain ingredients with lactose, too — and check food labels closely.

Know your body

The good news: Plenty of alternatives exist — almond-milk or soy-milk products, for example — and not all dairy products are off-limits.

Certain hard cheeses, such as Parmesan, are generally well tolerated. Or, if you eat too much in one sitting, even the low lactose levels can add up — and lead to symptoms.

Can lactose-free milk or supplements help?

Patients can try drinking lactose-free milk or taking supplements to help them digest lactose. Just be aware that these products have their limits.

Lactose-free milk has a sweeter taste than real milk, and many don’t like it. And with supplements, “you may not get enough lactase to digest the lactose before it hits the intestine,” Dr. Lee says.

With or without supplements, you may not have to avoid lactose completely to avoid symptoms, Dr. Lee says. Pay close attention to your diet to see what bothers you and what doesn’t — including portion sizes.

That means you may be fine eating one pancake made with milk. Just don’t have five of them.

In the end, though, if symptoms persist, know that giving up lactose is the best way to limit your symptoms.

“Once you give up those foods and have less diarrhea and gas, you’ll find that you won’t miss those foods that much,” Dr. Lee says.