Everything you need to know about lactose intolerance

Lactose intolerance typically develops later in childhood and can be easily managed.

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Savouring a sticky ice cream cone on a sunny summer afternoon is one of the greatest joys of childhood. But for some kids, indulging in the sweet treat is soon followed by a tummy ache, which might mean that they’re lactose intolerant. The condition typically develops after age three but doesn’t necessarily mean that your kid has to ditch dairy. Here’s what you need to know about lactose intolerance.

What is lactose intolerance?

Lactose intolerance occurs when you’re unable to properly digest lactose (the sugar in milk) due to a lack of lactase (the enzyme that breaks it down). Normally, lactose is broken down by lactase in the small intestine and absorbed. If this doesn’t happen, lactose goes into the large intestine, where bacteria break it down into gases and fatty acids, causing symptoms such as cramps and gas.

Lactose intolerance vs milk allergy

Lactose intolerance is completely different from a cow’s milk allergy, which occurs when your immune system mistakenly identifies a protein in milk as dangerous and mounts an attack, releasing chemicals that cause a reaction.

Toddler boy drinking a glass of milk Are milk alternatives actually unhealthy for kids?“Parents often get confused or think lactose intolerance and cow’s milk allergies are the same thing,” says Kevan Jacobson, head of gastroenterology at BC Children’s Hospital in Vancouver. “Lactose intolerance is an issue with lactose digestion, whereas a milk allergy is a sensitivity to the protein.”

If you’re allergic to milk, being exposed to even a small amount can cause a potentially life-threatening reaction that may involve the skin and respiratory, cardiovascular and gastrointestinal systems. In contrast, lactose intolerance only affects the gastrointestinal system, and many people can still tolerate small amounts of lactose.

Children typically develop a milk allergy in the first six months of life, and the majority outgrow it by age three, while lactose intolerance develops after age three and gets worse with age.

What are the different types of lactose intolerance?

Of the four types of lactose intolerance, primary lactose intolerance is the most common. It is genetic and shows up at different ages, depending on ethnicity. Everybody’s lactase activity naturally decreases over time. But for those with primary lactose intolerance, it drops to the point where they’re unable to digest certain levels of lactose, so they develop symptoms when they eat or drink foods with lactose.

Secondary lactose intolerance is a temporary condition that results from an injury to the small intestine due to an infection. This is why your mom may have told you to avoid drinking milk after a stomach bug.

There are also two types of lactose intolerance that affect babies. Congenital lactose intolerance is rare and occurs when infants are born with little or no lactase and show significant symptoms, such as severe diarrhea, which can lead to dehydration and weight loss. Developmental lactose intolerance occurs in preterm babies, typically born at 34 weeks or earlier. It quickly resolves as the digestive system matures.

How common is primary lactose intolerance?

The likelihood of your child developing lactose intolerance depends on their ethnicity. For example, lactose intolerance occurs in about 25 percent of people of European descent; 50 to 80 percent of Hispanic people, Black people, Ashkenazi Jews and those from south India; and almost 100 percent of Asian and Indigenous peoples in North America. In a 2013 survey of adults in Canada, 16 percent self-reported lactose intolerance.

When does primary lactose intolerance develop?

Children develop primary lactose intolerance at different ages, depending on their level of lactase. “Ethnic groups who are predisposed to lower enzyme activity have an accelerated decline in their levels of lactase,” explains Jacobson. “For most people with a higher risk, primary lactose intolerance tends to manifest in the first decade of life. For those with a lower risk, it’s variable, but it’s later on in life.” For example, Jacobson says that Hispanic, Asian and Black children often become lactose intolerant before their fifth birthday, whereas children of Western European descent typically do not develop symptoms until after age five and even into their teens.

What are the symptoms of lactose intolerance?

The symptoms of lactose intolerance typically set in 15 minutes to two hours after consuming dairy and range in severity, depending on the child’s level of lactase, how much lactose has been consumed and what other foods have been consumed with the lactose. Milk has more lactose than fermented dairy products, such as yogurt and cheese. Foods that are high in fat slow the emptying of the stomach, delaying the entry of lactose into the small intestine, which allows more time for the enzymes to digest properly. As a result, a kid who can’t tolerate a glass of milk may be able to eat a cheeseburger with fries.

Common symptoms include abdominal pain, diarrhea, gas and bloating. Children sometimes vomit and, in rare cases, may get constipated.

How do you diagnose lactose intolerance?

If you think your child is lactose intolerant, you should take them to the doctor and explain their symptoms. The doctor may make a diagnosis based on symptoms and the likelihood that your child is lactose intolerant, factoring in their age and ethnicity.

A a pH stool test may be done to confirm a diagnosis in infants and may be used to investigate further in the case of older children. The fatty acids produced due to lactose intolerance are very acidic, but Jacobson says that the test is not highly accurate.

A better test is the hydrogen breath test, in which a child drinks a liquid that contains lactose and breathes into a container and their breath is captured and tested for hydrogen, which is produced when bacteria act on the lactose in the large intestine. The breath test can’t be done on children younger than five because they can’t breathe reliably into the container.

You can also determine if your child is lactose intolerant by eliminating dairy from their diet or giving them synthetically produced lactase in tablet or drop form and seeing if their symptoms go away. If you’re worried about giving your child lactase before you even know if they’re lactose intolerant, Jacobson assures parents that it’s not dangerous. “There’s no real downside to taking the enzyme,” he says.

Is there a cure for lactose intolerance?

There is no known cure for lactose intolerance, nor is there a way to make your body produce more of the lactase enzyme to break it down. The good news is it can managed through diet and supplements.

How do you treat lactose intolerance?

If your child is lactose intolerant, they can avoid dairy, take lactase or do both. Lactase only needs to be taken before consuming lactose, so your child could avoid dairy most of the time and take lactase before a birthday party with cheese pizza and ice cream cake.

“We usually suggest the enzyme,” says Jacobson. “If you eliminate dairy, you have to be sure that the child has adequate calories, calcium and vitamin D—that’s very important.” Jacobson recommends that parents who opt to eliminate dairy see a dietitian to ensure that their child is getting the nutrition they need.

What foods should your child avoid if they’re lactose intolerant?

If you opt for your child to avoid lactose rather than take lactase, they may need to steer clear of a number of kid favourites, including milk, yogurt, ice cream and cheese. Fortunately, there are many cow’s milk alternatives on the market today, such as lactose-free cow’s milk, goat’s milk (which has less lactose than cow’s milk) and soy and nut milks. However, Jacobson cautions that some of these products lack nutrients, so it’s important to check the labels or speak with a dietitian. For example, goat’s milk is naturally deficient in folic acid, as well as vitamin D, B12 and iron, though some products have been fortified with one or a combination of these nutrients.

Breastmilk and cow’s milk formulas both contain lactose. Children with developmental lactose intolerance can typically consume breastmilk or cow’s milk formula, but those with congenital lactose intolerance must be fed lactose-free formula. Infants with secondary lactose intolerance can continue to consume breastmilk or cow’s milk formula.

Some people with lactose intolerance can handle some lactose, but the amount decreases over time as their lactase levels drop. Fermented dairy products, such as yogurt and certain cheeses, contain less lactose than milk, so some lactose-intolerant individuals may be able to eat these products without experiencing symptoms. Trial and error is the only way to determine if your child can tolerate certain dairy products.

Dairy is an ingredient in many foods, and baking or processing milk products doesn’t break down the lactose. Dairy can be found in baked goods, snack foods, salad dressings and frozen meals. Often, the amount of dairy is negligible and unlikely to cause symptoms, but it’s always worthwhile to read the labels and contact the company if you’re concerned.

“If you’re lactose intolerant, it shouldn’t have a significant impact on your life as long as you take the necessary steps,” says Jacobson. “You just require some dietary changes. It’s easily manageable.”

Read more:
How to know if your kid has a food allergy or food intolerance
Your guide to life after a food allergy diagnosis

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