Bad news cheeseheads. Lactose intolerance can strike in your 20s, 30s, and beyond.

How can you develop lactose intolerance?

Lactose intolerance (aka lactose malabsorption) can develop at any age. It can be triggered by a variety of things like:

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We have all the dietary deets plus some top tips on how to ditch the dairy.

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Lactose intolerance is when your body can’t break down lactose, a natural sugar found in dairy products. It usually happens when your small intestine stops making enough lactase, an enzyme that helps you digest lactose.

If you’re lactose intolerant, enjoying a glass of milk or your fave dairy goodies can cause symptoms like:

When it comes to lactose intolerance, age is nothin’ but a number. It can crop up at any time.

There are four main types of lactose intolerance:

  • primary
  • congenital
  • developmental
  • secondary


Lactase levels are usually highest when you’re a bébé and decrease as you age. In fact, about 75 percent of adults don’t produce enough lactase.

If your lactase levels are too low, you can develop primary lactose intolerance. It’s the most common type of the condition and is caused by an inherited gene.


Congenital lactose intolerance is a rare condition that affects infants. It’s inherited and both parents need to carry the gene to pass it on.


Babies born prematurely may experience developmental lactose intolerance. It happens when the baby’s body can’t produce enough lactase because the small intestines aren’t fully developed. It tends to be temporary.


Secondary lactose intolerance can develop when there’s an issue with the small intestine. It can be caused by an infection, illness, or intestinal surgery.

Risk factors for lactose intolerance

  • Premature birth. Premature babies may produce less lactase because their intestines haven’t fully developed.
  • Ethnicity. Those of African, Asian, Hispanic, and Native American descent have a higher risk of developing a lactose intolerance.
  • Aging. Your natural lactase levels get lower as your get older.
  • Some cancer treatments. Intestinal complications from chemotherapy and radiation therapy for stomach cancer can increase the chances of developing lactose intolerance.
  • Certain conditions. Health conditions that affect the small intestine can cause lactose intolerance.
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Certain conditions can increase your risk of secondary lactose intolerance. This includes:

There’s also a chance a medication you take could be increasing your sensitivity to dairy. Antibiotics and chemotherapy treatments are common culprits.

If dairy’s giving you grief, it’s time to talk with your doc. They can give you a test to see what’s going on.

  • Hydrogen breath test. During this test, you’ll start by drinking a lactose-filled fluid. Then your doc will measure the hydrogen in your breath. High levels of hydrogen can be a sign that you’re not absorbing enough lactose.
  • Lactose tolerance test. Your doc will give you a blood test 2 hours after you drink a high-lactose drink. If your glucose levels don’t rise, it can be a sign you’re not digesting lactose properly.

If you have a mild intolerance, you might still be able to tolerate small amounts of lactose without issue.

But what if any amount of lactose doesn’t agree with you? The most obvious way to treat lactose intolerance is to avoid foods with lactose. You can also take lactase supplements (like Lactaid) before drinking or eating dairy. These may help you enjoy your fave foods without the GI side effects.

Probiotics may also help, but certain strains would need to be chosen.

If lactase supplements aren’t your jam, here’s how you can still get your dairy fix:

  • Milk: milk products labeled “lactose-free” (like the Lactaid brand) or nondairy milks like almond, coconut, oat, or soy milk
  • Dairy-free cheese: vegan cheese, nutritional yeast
  • Low-lactose cheeses: Colby, cheddar, Monterey jack, Swiss, and Parmesan cheeses
  • Yogurt: soy, almond, coconut, or cashew-based yogurts (plus, dairy yogurts with live active cultures are often OK because the cultures use up the lactose)
  • Ice cream: lactose-free dairy ice cream or dairy-free options like almond or coconut milk-based ice creams and sorbets

Can you still get the same nutrients going dairy-free?

Cow’s milk dairy products are great sources of calcium and other essential nutrients like protein, vitamin D, vitamin A, and several B vitamins (including B12).

Drinking lactose-free dairy milk already has the lactose broken down and provides the same nutrition as regular cow’s milk. Generally speaking, soy milk is the closest nondairy nutritional equivalent to cow’s milk.

Most nondairy milks have less protein compared to cow’s milk (about 1 to 2 grams compared to 8 grams), and they aren’t typically fortified with vitamin D or calcium.

If you’re not down with dairy, your doc might suggest dietary supplements or changes to your diet to help you keep your levels on fleek. But just taking a calcium supplement won’t replace all these essential nutrients you’d get from moo juice.

Other nondairy options like leafy greens, seafood, almonds, and calcium-fortified orange juice are all great sources of calcium.

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Lactose intolerance can develop at any age. It can be triggered by a health condition, like celiac disease or an intestinal infection. But it can also be heredity or a symptom of aging.

The good news is that there are ways to manage your lactose intolerance. Taking a lactase supplement can often do the trick and let you enjoy dairy without symptoms. Others may need to cut dairy out of their diet or eat low lactose or lactose-free dairy products.