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8 Things No One Ever Tells You About Being Lactose Intolerant

Like the fact that even if you’re not lactose intolerant now, there’s a good chance you will be some day.

Even though you likely guzzled milk like crazy when you were a kid, you may have noticed that, as you’ve gotten older, dairy doesn’t always agree with your stomach. For some, that discomfort grows, leading to gas, bloating, stomach cramping, and even diarrhea, which may herald the arrival of lactose intolerance.

“If you have lactose intolerance, you can’t digest lactose—the main sugar in milk and other dairy products,” Keri Gans, registered dietitian and author of The Small Change Diet, says. “With lactose intolerance, your small intestine doesn’t make enough lactase—the enzyme that digests lactose.”

If you’re like a lot of people, that’s about where your knowledge of lactose intolerance stops. Here are some things you may not know about this common digestion problem.


1. Most of us are heading for lactose intolerance.

Bad news if you’re an ice cream lover: Research shows that about 75 percent of the world’s population loses the ability to break down lactose at some point, meaning that many naturally become lactose intolerance over time. In the U.S., the condition affects around 30 million adults to some degree by age 20, according to the National Institutes of Health (NIH).

2. Babies can be lactose intolerant, too.

In some cases, infants are born lactose intolerant. This happens when babies have a mutation of the LCT gene, which normally delivers instructions for making that key enzyme, according to the NIH. That, in turn, causes the baby’s small intestine to produce little or no lactase from birth, making dairy problematic. According to the National Institute of Diabetes and Digestive and Kidney Disease (NIDDKD), children can inherent genes that cause congenital lactose intolerance from their parents. But don’t fret: The condition in babies is extremely rare since nearly all infants have the enzyme that breaks down lactose.

3. Some ethnicities are more likely to develop it than others.

Lactose intolerance is most common among people of East Asian ancestry, affecting more than 90 percent of adults in some communities, according to the NIH. The condition is also common in people who are of Jewish, Arab, West African, Greek and Italian descent. On the flip side, people with ancestors from Northern Europe, who often consume a lot of unfermented milk in their diet, have only a 5 percent rate of the disorder.

4. Lactose intolerance doesn’t affect everyone the same way.

People can be lactose intolerant and yet have wildly different reactions to consuming dairy products, according to Gans. Small amounts of lactose can cause major symptoms in some, such as diarrhea and abdominal pain, while others may only have a mild reaction, such as gas. It’s not clear why symptoms vary so much in different people, but it may have something to do with an individual’s gut bacteria.

5. Symptoms tend to kick in shortly after downing dairy.

According to the NIH, bloating, gas, cramping, or diarrhea often crop up 30 minutes to two hours after consuming dairy in people who are lactose intolerant. And the more milk products you consume, the worse you feel.

6. You may still be able to eat certain types of cheese and yogurt.

Just because you’re lactose intolerant doesn’t mean you have to automatically say sayonara to all forms of dairy. While some people aren’t able to digest much at all, others may find that they have no trouble with yogurt, which contains fermented milk, or aged hard cheeses, such as Parmesan and cheddar. “Aged cheeses have trace amounts of lactose,” explains Gans, which makes it easier to digest for some. “It really is trial and error for many. Also, lots of people do better with lactose if they consume it with other foods and not strictly on its own.”

According to the NIDDKD, research suggests that adults and teens who normally have trouble absorbing lactose are able to eat or drink at least 12 grams of it in one sitting with little to no problems. To put that in perspective, 1.5 oz of low-fat hard cheese contains less than 1 gram of lactose, while 1 cup of low-fat milk has about 11 to 13 grams of lactose.

7. But cutting down on dairy means you might be lacking in vitamin D and calcium.

Dialing down on dairy can mean your bone-bolstering calcium and vitamin D levels also take a nosedive. If you have trouble consuming milk products including yogurt, talk to your doctor about taking calcium and vitamin D supplements and up your intake of calcium-rich foods such as lactose-free milk, spinach, sardines, pinto beans, and broccoli.

8. You may be able to build up your tolerance a bit.

While it sounds like a risky—not to mention un-fun—experiment for anyone with moderate to severe symptoms of lactose intolerance, some experts say that consuming small amounts of milk, such as a quarter cup on a full stomach two or three times a day, can help recondition your digestive system to break down dairy without discomfort.

But according to the Mayo Clinic, there currently isn’t a way to boost your body’s production of lactase. “If your small intestine doesn’t make enough [of the digestive enzyme], it isn’t all of a sudden going to work,” Gans says. “But one should really experiment and find out what works for them instead of automatically eliminating all dairy.”