What Is Lactose Intolerance?
Lactose intolerance is caused by low levels of lactase, an enzyme that helps you digest lactose in dairy foods, says Laura Acosta, a registered dietitian at the University of Florida in Gainesville.
“Some people are able to tolerate lactose throughout their lives, but others become more lactose intolerant as they age,” usually caused by your genes, she says. “Some people stop producing lactase, or produce less of it, as they reach adulthood and beyond.”
Who’s More Likely to Get It?
Lactose intolerance is more common among people of Southeast Asian, East Asian, West African, Native American, Hispanic, or Italian ancestry because they’re more likely to carry the gene mutation that causes the condition, says Vijaya Surampudi, MD, assistant professor of medicine at the University of California, Los Angeles.
“We have the highest amounts of lactase when we are young because as babies, we feed on milk. But we often make less and less lactase as we age,” she says. “About 65% of people may experience lactose intolerance at some point in their lives.”
There’s a wide range of lactose intolerance, with some people having no tolerance for dairy, while others can manage to digest foods like hard cheeses or yogurt, she says.
It’s fairly common to notice the signs of lactose intolerance appear as you get older, says Christine Lee, MD, a gastroenterologist at Cleveland Clinic in Ohio.
“This enzyme production can decrease over time in some people, so most people can experience some degree of lactose intolerance as they get older,” Lee says. You can also become lactose intolerant if you have an illness, infection, or take a medication that affects the bowels or intestines.
These conditions can also cause you to develop lactose intolerance later in life:
What Can Trigger Symptoms?
Foods. Any dairy foods or drinks can have lactose, so read food labels carefully. These foods or ingredients may trigger symptoms:
Look for milk in ingredients lists in baked goods, chocolate candies, sauces, instant mashed potatoes, pancakes, or milk-based meal replacement or protein shakes. Even non-dairy coffee creamer or whipped toppings may contain some lactose.
Medications. Some medications like birth control pills or antacid tablets also contain lactose, but these may only cause symptoms in people with severe lactose intolerance. Check the labels of your prescription or OTC medications to see if they contain lactose. Ask your doctor or pharmacist if it’s OK for you to take them.
Can You Still Eat Dairy?
You may not have to give up all the dairy foods you enjoy if you develop lactose intolerance.
Some people with lactose intolerance may be able to eat or drink small amounts of dairy or switch to skim milk and have fewer symptoms. Some people can eat yogurt because it contains live bacteria cultures that help you produce the lactase enzyme to break down lactose.
“Cheese actually has very little lactose. In general, the harder the cheese, the less lactose it has. So many people with lactose intolerance can still tolerate cheese like Parmesan and Swiss in small amounts. This depends on an individual’s sensitivity,” Acosta says.
Talk to your doctor to identify what’s causing your lactose intolerance so you can make the right changes to your diet, Lee says.
“If it’s due to decreased production of lactase, then you can choose to take lactase tablets or drops, enzymes sold in most grocery stores without a prescription, or buy lactose-free milk products,” she says. Supplements are taken before a meal with dairy to help you digest the lactose.
If your lactose intolerance is due to a bowel disease or other health conditions, treat that illness first, she adds. “Always play it safe and discuss your symptoms with your physician.” Unexplained weight loss, bleeding, anemia, nausea, or vomiting may be signs of a more serious medical condition, not just lactose intolerance, she says.
Make Sure You Get Your Calcium
“There are many calcium-rich foods people can eat if they’re avoiding lactose,” says Allie Wergin, a registered dietitian/nutritionist with Mayo Clinic Health System. “These include lactose-free dairy products like Lactaid or Dairy Ease milks, where the lactose is predigested or hydrolyzed. This means the milk protein has already been broken down and is easier to digest.”
Other foods that are good sources of calcium, according to Wergin:
- Calcium-fortified cereals and fruit juices
- Tofu prepared using calcium sulfate
- Canned salmon or sardines with bones
- Plant-based soy, almond, oat, or rice milks
- Leafy green vegetables like spinach, kale, bok choy, or collard greens
- Beans like garbanzo, kidney, or navy
“We recommend that you get calcium through your diet. There are different calcium supplements, including calcium carbonate, which is best absorbed if you take it with food, and calcium citrate, which you can take with or without food,” Surampudi says. Only take a calcium supplement if your doctor says you need one, she says.