Lactose Intolerance: Are there long-term effects?

Lactose intolerance is present in about 70% of the world’s population. And yet, some information about lactose intolerance is misunderstood and confused with other gut disorders. I want to clarify things today. This post goes into more detail about concerns about long-term effects of lactose intolerance and what can be done to limit risks of lactose intolerance. I’ll also cover a few tips for people with lactose intolerance who still hope to enjoy some dairy foods.

What is lactose intolerance? Can kids be lactose intolerant?

Lactose intolerance is when a person cannot completely digest a food that has lactose. Lactose is in most dairy products. It’s the main carbohydrate in milk. It is extremely rare for kids under age 3 to be lactose intolerant. They usually still have plenty of the enzyme called lactase that helps break down the lactose. Even then, many other kids who grow up to be lactose intolerant don’t have many symptoms until they’re closer to adolescence. This varies a lot depending on ethnicity.

Short-term symptoms of lactose intolerance

If someone is lactose intolerant and eats too much dairy, they may have symptoms like stomach pain, bloating, passing gas, diarrhea, nausea, and general discomfort. This threshold of “too much” dairy varies from person to person. Some lactose intolerant people can handle more dairy than others. They may find that they can comfortably eat different amounts in different situations (more on that later). 

How does lactose cause bloating and other symptoms?

Here is a quick example of one way lactose intolerance leads to some of these symptoms. Ideally, the lactose in food gets to the small intestine. The enzyme lactase hangs out in the small intestine and breaks down the lactose. Then, it’s absorbed, in the broken-down forms. If there’s not enough lactase, it can’t all be broken down and absorbed. Guess who loves the regular intact lactose that’s left behind? Some gut bacteria! Our guts are full of bacteria, also called the gut microbiome. So, the bacteria digest the lactose and release gasses. Enough gas? That leads to some of the classic discomfort and bloating.

But, do these unpleasant symptoms cause damage to the intestines?

A common “treatment” for lactose intolerance includes simply avoiding foods that cause symptoms. However, sometimes people ask what happens if you’re lactose intolerant and keep eating dairy products? Are there long term effects of lactose intolerance? 

Fortunately, lactose intolerance does not usually cause long-term damage to the gut or intestines. If the lactose isn’t broken down, it can be uncomfortable, but not dangerous.

This is strikingly different than other gut disorders that are partially treated with diet. So, although someone with lactose intolerance could keep eating dairy without physical damage to their body, the same is not true for people with milk allergy. Lactose intolerance is different from cow’s milk allergy, celiac disease, milk sensitivity, inflammatory bowel disease, and other gut disorders. Please see your or your child’s physician for specific guidance!

One long-term risk of lactose intolerance, especially in kids.

However, this is not to say that lactose intolerance is harmless, aside from a few uncomfortable symptoms. Because a limited diet is one way we treat this, then anyone who limits dairy also risks missing out on some key nutrients from dairy. I speak specifically of calcium and vitamin D. This is especially important when we think about kids and bone health (as this study showed).

So, yes, there are long term risks of lactose intolerance, but they actually come from not eating dairy rather than eating dairy despite all the symptoms. 

So what’s a parent to do if their child is miserable everytime they drink cow’s milk or eat cheese?

There’s a lot parents can do for their lactose-intolerant kids. First, they need to make sure their kids get enough calcium and vitamin D. Second, there might be a few ways they can still enjoy some dairy without too much discomfort.

Good news. We have many ways to get calcium and vitamin D. 

As a reminder, goals for calcium are 1300mg for teens and kids over age nine. Nondairy foods that have calcium include: spinach, beans, some fish (like sardines), and nuts. Many foods are fortified, like some cereals. Check labels, especially on plant-based drinks like almond “milk.”

We aim for about 600 IU vitamin D daily for kids over age 1 year. Vitamin D supplements are reasonable for many kids.

Dairy options for some people with lactose intolerance.

Many families seem to figure out what little tweaks to their diet allow their kids to enjoy some dairy products. I’ll share a few here. Please keep in mind they do not apply to everyone.

First, we need to remember that it’s not exactly dairy that causes tummy troubles, but lactose. Different dairy products have different amounts of lactose. Again, the lactose is broken down by lactase in the intestines. Most people with lactose intolerance have some lactase, just not enough to handle an unlimited amount of dairy.  So with that in mind, here are a few options that work for some people with lactose intolerance:

Aged cheese

Aged cheese has less lactose than fresh cheeses. Remember that the cheese-making process includes bacteria. The bacteria may help break down the lactose. So, the longer a cheese ages, the less lactose it may have. So, many lactose intolerant people can enjoy larger quantities of aged cheeses. One example is parmesan. For references, some of the higher-lactose cheeses are mozzarella or brie.

Plain yogurt

Plain yogurt has (good) bacteria in it that naturally have lactase activity. So, they help break down some of the lactose before it even reaches the gut.

Accompanying foods

If someone eats solid foods when they drink milk, everything passes through the gastrointestinal (GI) system a little more slowly. Think about eating a big solid meal as opposed to drinking something. Your stomach feels full a little longer with the food, right? Well, people with lactose intolerance can use this to their advantage. If everything (including the lactose-containing food) passes more slowly, it spends more time in the small intestine. So, the lactase in the small intestine has more time to do it’s job of breaking down lactose. More broken-down lactose means fewer symptoms. So, if a child needs to drink some milk, they’ll probably be more comfortable if they have some food with it. 

Dairy products modified for those with lactose intolerance

Finally, there are dairy products on the market for people with lactose intolerance. Many stores have reduced-lactose milk. And, there are supplements containing lactase (the enzyme that breaks down lactose). Some people find relief if they take the lactase with dairy products.

Summary: Long-term effects of lactose intolerance are related to nutrition overall, not just the intestines.

Although lactose intolerance does not cause long-term damage to the intestines, people with lactose intolerance still need to be thoughtful when choosing their diet. Again, lactose intolerance is not the same as milk allergy.

Maya M. Mahmood, D.O., F.A.A.P. is a board-certified pediatrician and mom. She is passionate about parents having evidence-based information to help their families be healthier. Subscribe to the newsletter or follow on social media @mayapeds.

Photo by Eiliv-Sonas Aceron on Unsplash