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Can You Become Lactose Intolerant Over Time?

Answering this and any other questions you may have about lactose intolerance.

Lactose intolerance is a mystery for many people.

If you’re a dairy lover, you might fear suddenly being unable to tolerate your favorite foods.

Could that pizza that once made you happy, ruin your day, one day?

What if you can’t eat ice cream anymore?

Can you become lactose intolerant over time?

If these are things that concern you, stay tuned.

We’re here to demystify what lactose-intolerance is and explain how it develops.

By the end of this, you’ll be able to identify its symptoms, know who is most affected by it, and learn how to navigate eating if you have it.

What is lactose intolerance, and can it develop over time?

Most people vaguely know that lactose intolerance dairy products will blow your stomach up.

While this is true, people often don’t know what happens in a lactose-intolerant person’s body if they drink milk.

Essentially, lactose-intolerant people can’t process the lactose (sugars) in milk. People can’t process lactose because they don’t have enough lactase, an enzyme that breaks lactose down.

If your body can’t process the lactose, your bloodstream can’t absorb the broken-down sugars through the intestinal lining. 

These sugars continue to the colon, where they mix-and-mingle with bacteria and wreak havoc.

There are three main types of lactose intolerance:


Primary lactose intolerance is the most prevalent form. People start life with enough lactase, but they rapidly stop producing the enzyme as adults. 

You fall in love with all the yummy dairy products as a child and have to mourn the loss of your favorite treats in your adult life. 


Secondary lactose-intolerance happens when an illness, surgery, or injury affects your small intestine’s lactase production.

Chron’s disease, bacterial overgrowth, intestinal infections, and celiac disease can cause secondary lactose intolerance. 

Over time, treatment can help improve your lactase levels and your symptoms to help you eat your favorite dairy treats again.

So secondary lactose-intolerance will make you lactose-intolerant but with treatment and time it’ll gone away.

Congenital or developmental 

Some people are born with insufficient lactase. It is a rare occurrence that happens when both the mother and father have a disorder called autosomal recessive.

Another instance where lactose-intolerance can occur at birth is with premature babies. It doesn’t happen every time, but it does increase the baby’s chances. 

So can you become lactose intolerant over time?

Yes, most people do! It is rare for people to be born with lactose intolerance. However, many adults produce less lactase over time, resulting in being lactose intolerant as an adult.

What are the symptoms if I’m lactose intolerant?

If you’re reading this and questioning if you have lactose intolerance, there are some telltale sights that you might have it. Your body will often tell you loud and clear if it doesn’t like the dairy you are eating.

Here are some indicators that might mean you’re lactose intolerant:

Stomach pain and bloating

One of the most common symptoms of lactose-intolerance is stomach pain and bloating.

Remember how lactose gets friendly with bacteria in the colon?

Well, this causes fermentation, which leads to the release of methane and carbon dioxide.

There’s an increase in water and gas, which leads to pain and bloating.


A less desirable symptom of lactose-intolerance is diarrhea.

The fermented, undigested lactose creates short-chain fatty acids, increasing your gut’s water levels.

More water in the gut has to go somewhere.

When it comes out, it is more watery than usual, which is why you might have diarrhea after drinking milk.

Increased gas

All that fermentation really does something to your body.

When your gut turns lactose into gases and acids, it makes you flatulent.

Flatulent is just a fancy word for gassy.

Fun fact, gases from lactose fermentation are odorless. It’s actually the breakdown of protein that makes gas silent but deadly.


Many lactose-intolerant people get diarrhea, but some have the opposite happen to them.

Similar to the other symptoms, this symptom happens when your colon has increased methane production.

The increase in methane can slow down movement in your gut.

Researchers are still figuring out why this phenomenon happens sometimes.


Most symptoms revolve around what happens in your gut. However, some people with lactose-intolerance have other symptoms.

These include:

  • Fatigue
  • Brain fog
  • Headaches
  • Muscle and joint pain
  • Ulcers in the mouth
  • Eczema
  • Difficulty urinating

It is unclear whether lactose-intolerance causes these or if it is related to other underlying issues.

Milk allergy or lactose intolerance?

If you have different symptoms while drinking dairy, you may have milk allergies.

Milk allergies are not lactose intolerance.

Symptoms often include:

  • Anaphylaxis
  • Asthma
  • Rash and eczema
  • Vomiting, stomach pain, and diarrhea

While lactose intolerance can feel pretty terrible, it isn’t deadly. However, milk allergies can be severe and life-threatening.

Who is most affected by lactose intolerance? 

Who does lactose-intolerance affect the most?

The answer is, quite a few people.

According to Medline Plus, lactose-intolerance affects 65% of all humans.

That’s A LOT of people!

Adulthood lactose intolerance is most common among East Asians, with 70-100% of these communities affected.

However, it is also common in individuals of West African, Jewish, Greek, Arab, and Italian descent.

It is the least common in cultures where unfermented dairy is typical, for example, in Northern Europe.

What should I do if I’m lactose-intolerant?

Foods to avoid

If you’re lactose-intolerant, avoid milk, right?

Well, it’s not always that simple.

Some of the more apparent foods to avoid are milk, yogurt, and sour cream.

However, you’ll find out pretty quickly that A LOT of foods have dairy products in them.

Not all of them are suitable for lactose-intolerant people.

Foods that often have hidden lactose in them are:

  • Cake and cookie mixes
  • Salad dressing
  • Creamers
  • Processed meat
  • Soups
  • Alcoholic beverages

Some lactose is a part of foods that has noticeably creamy flavors. However, food processing companies sometimes use it as a bulking agent and for flavoring. Super sneaky!

Foods that are okay to eat

Okay, so anything dairy-related is off-the-table?

Not necessarily.

You’ll be surprised that many foods seem like they would be a no-no but are fine.

Keep in mind that if you have a dairy allergy, you’ll need to avoid these items.

Dairy that has an insignificant amount of lactose include:

  • Some hard aged cheeses – think parmesan, swiss, etc.
  • Butter
  • Lactaid milk and milk products
  • Yogurt with live cultures or probiotics

There are also plenty of dairy-free alternatives, including plant-based milk, cheese, yogurt, and ice cream.

You can also take lactose supplements to help you digest unfriendly dairy.

While lactose-intolerance limits your choices, you can still enjoy many foods!

Bottom line

Lactose-intolerance is an irritating condition caused by a shortage of lactase enzymes in your intestines.

It can wreak havoc in your gut, causing uncomfortable symptoms.

Some people are born with it, and others develop it in adulthood.

While frustrating, a lactose-intolerant person can still enjoy their favorite foods with supplements, dairy-free alternatives, and lactose-free dairy.

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