I’m Lactose-Intolerant. Can I Eat Dairy Anyway?

Q: I recently learned that I’m lactose-intolerant. Do I really need to avoid all dairy, or are some products safe to eat?

Some 30 to 50 million people in the United States have lactose intolerance. This means their bodies can’t adequately break down lactose, the sugar present in milk.

The result can be uncomfortable gas, bloating, nausea, diarrhea and abdominal pain, symptoms that typically occur within about 30 to 60 minutes of eating a lactose-rich food, said Beth Ferrell Jenks, a dietitian and assistant professor of nutrition at the University of North Carolina at Chapel Hill.

The good news: While individual tolerances to dairy foods can vary, certain lower-lactose dairy products, like hard cheeses and yogurts, can help keep lactose intolerance symptoms at bay.

How to Eat With Lactose Intolerance

Trouble with lactose intolerance tends to begin in adulthood, when our bodies gradually makes less lactase, an enzyme that breaks down lactose.

Some people might not notice this change in their digestion, said Dr. Suneeta Krishnareddy, a gastroenterologist at Columbia University Irving Medical Center in New York City. But others may have symptoms so severe that they experience nausea and vomiting after eating certain foods, said Dr. Nitin K. Ahuja, a gastroenterologist at Penn Medicine in Philadelphia.

Understanding your triggers involves some trial and error. You might start by eliminating all dairy from your diet, and then gradually reintroduce small amounts of certain foods and drinks containing lactose to see how you feel afterward.

Here are the dairy products most, and least, likely to exacerbate your symptoms.

The Worst Offenders

Dairy milk: Skim, 1 percent, 2 percent and whole milk all contain between 12 and 12.5 grams of lactose per cup. That’s around the maximum amount of lactose people with an intolerance can consume per day without having symptoms, said Ella Haddad, a dietitian and professor emeritus of nutrition at Loma Linda University in California. So try to limit yourself to one glass of milk per day, or less if you’re consuming other types of dairy.

Unaged (or fresh) cheese: Cheese generally contains less lactose than milk, but some varieties have more than others. Cheeses that haven’t been aged — meaning they haven’t been left to ripen for weeks, months or years — typically contain more lactose than aged cheeses, Ms. Jenks said. This is because during the aging process, bacteria break lactose down, converting it into lactic acid.

Unaged cheeses tend to be soft and moist and often come in a tub. A half-cup serving of cottage cheese with 2 percent milk fat contains about four grams of lactose. Two tablespoons of fat-free cream cheese has nearly two grams. While unaged cheeses are probably more tolerable than dairy milk, Ms. Jenks recommended limiting them when you have the choice.

Ice cream: Many ice creams, which are mainly made from milk and cream, are rich in lactose and therefore should be limited. But some versions contain more lactose than others. If an ice cream contains more milk than cream (you can tell by checking if milk is listed before cream on the ingredients list), it is probably rich in lactose and therefore harder to digest, Dr. Haddad said. This is because milk contains more lactose than cream.

OK in Moderation

Hard cheese: Varieties like Parmesan, Cheddar and Swiss have been aged and therefore contain very little lactose and are often easier to digest than softer, unaged varieties, Dr. Krishnareddy said. Harder cheeses tend to taste sharper and include an outer rind. A one-and-a-half-ounce serving of Parmesan or Cheddar, for instance, contains less than one-tenth of a gram of lactose.

Other fermented dairy products: Fermented dairy foods like yogurt, kefir and sour cream contain bacteria that help break down lactose, Dr. Krishnareddy said. This lessens the load on your small intestine, making those foods easier to digest.

Butter: This kitchen staple is made from milk, cream or both by separating the fat from the rest of the liquid, leaving most of the lactose behind, Dr. Haddad said. One pat of butter and one tablespoon of cream each contain about half a gram of lactose or less.

What Else Can Help

Many supermarkets carry lactose-free dairy products like milk, cheese, yogurt and ice cream. They are regular dairy products made from milk but with the lactase enzyme mixed in. This makes them more tolerable if you’re lactose-intolerant, Ms. Jenks said.

Dairy-free products like milk made from almonds, soy or oats; cheese made from nuts; and ice cream made from soy or coconuts are also lactose-free.

Over-the-counter lactase enzyme supplements, which can be swallowed or chewed, can help reduce your indigestion symptoms when taken with a meal. They contain the lactase enzyme so your body doesn’t have to make it itself, Dr. Krishnareddy said.

While many people can tell if they’re lactose-intolerant on their own, Dr. Ahuja said that it’s usually a good idea to see a doctor for a proper diagnosis. Other conditions, like food allergies or inflammatory bowel disease, can cause similar symptoms.