What You Should Know About Milk Allergy vs. Lactose Intolerance

What You Should Know About Milk Allergy vs. Lactose Intolerance

Most of us have dairy all the time. While we can agree that it tastes good, consuming it can lead to negative health effects.

Some of us can enjoy dairy products without any problems. For others, it causes digestive discomfort, but nothing too serious. A friend of mine refuses to stop eating pizza – even though he knows he’ll be uncomfortable after. A small percentage of us are even severely allergic.

You’ve probably heard terms like “milk allergy” and “lactose intolerance” before. People have a habit of using them interchangeably. So there’s plenty of confusion on the topic.

It’s time to get to the bottom of this. There are actually significant differences between a milk allergy and lactose intolerance. Once you understand the tell-tale signs of each condition, you can see if any of the symptoms sound familiar and take action to improve your quality of life.

Let’s get started!

Dairy Allergies

People often get confused and treat dairy allergies and lactose intolerance like they’re the same things. But they are actually quite different.

The key difference between the two: those who are allergic trigger a response from their immune system after consuming dairy. Lactose intolerance, on the other hand, has to do with the enzyme lactase. More on that in just a bit.

Some people use the term “milk allergy” while others use “dairy allergy.” In this case, the terms are actually referring to the same thing. It’s more practical to use dairy allergy because if you just tell someone that you have a milk allergy, they might assume you could have other dairy products – yogurt, cheese, etc. – without any issues.

How does it work?

It comes down to a case of mistaken identity. Your body recognizes the milk proteins as harmful invaders, which triggers an inflammatory response within the immune system. This overreaction (the immune system triggering when it shouldn’t) leads to unpleasant – or even dangerous – symptoms.

Dairy allergies usually appear very early in life. They affect about 2.5 percent of children younger than three. While this can cause problems for breastfeeding infants, between 60 and 80 percent of children with dairy allergies grow out of them by the time they are teenagers. Dairy allergies are very rare among adults.

Dairy Allergy Symptoms

Now that you understand how dairy allergies work, let’s turn to the symptoms.

There’s actually a huge variation here – everything from mild to life-threatening. The severity depends on the individual. Some people are much more allergic than others.


Here are some of the most common dairy allergy symptoms:

  • Anaphylaxis (a severe, life-threatening allergic reaction – this is very rare)
  • Breathing problems
  • Diarrhea
  • Dizziness
  • Hives
  • Itching
  • Rashes
  • Stomach pain and nausea
  • Swelling
  • Swelling of the lips and/or throat
  • Wheezing

There’s quite a variety of symptoms. We can’t predict exactly when to expect them. Some people with dairy allergies see red flags within minutes of consuming a dairy product. But for others, it takes up to several days for symptoms to appear.

Now that you have a better idea of how dairy allergies operate, let’s discuss the different milk proteins that can trigger the allergic response.

Casein Allergy

Casein is a protein found in cow milk and other dairy products.

This protein is one of the top offenders for people with dairy allergies. The pieces start to fit together once you realize it has a similar structure to gluten, the wheat protein that causes digestive nightmares and a leaky gut for millions.

How does it happen?

A casein allergy occurs when your immune system mistaken identifies the protein as a harmful invader. This causes your body to respond like it would when faced with a virus or dangerous bacteria. Production of IgE antibodies (immunoglobulin) ramps up as the body attempts to protect itself.

It doesn’t stop there. The antibodies react with the casein, triggering the release of chemicals like histamine. That leads to symptoms like:

  • Swelling (lips, mouth, face, tongue, throat)
  • Skin reactions (hives, rashes, itchy skin)
  • Nasal congestion (coughing, itchy eyes, runny nose, sneezing, breathing problems)

Not all casein is created equal. Casein is actually made up of smaller building blocks called “beta-caseins.” These beta-caseins vary depending on the breed of cow providing the milk. Older breeds (like Jerseys, Asian and African cows) produce A2 beta-casein. More research needs to be done, but for now it seems A2 is a much healthier choice. One study noted that people who drank milk with high levels of A2 have a “lower incidence of cardiovascular disease and type 1 diabetes” than A1 groups.

Newer breeds (like Holsteins and Friesians), on the other hand, produce A1 beta-casein. A Chinese study tracked the effects on people who drank A2 milk versus a group that drank an A1/A2 mix and found the mixed group had worse digestion, higher markers of inflammation, and more lactose intolerance than the A2 group. Another comparison study found A1 milk drinkers experienced greater abdominal pain.

Depending on where you live, it can be hard – if not impossible – to get dairy products made from A2 cows. Figuring out which breeds provided the milk can be difficult without a connection to a local dairy farmer.

Whey Allergy

Whey is another protein found in milk.

If you’re into weightlifting, you’ve probably already heard of it. It’s often processed into powder form and used in shakes and protein drinks.

Most people can tolerate whey just fine, but for some, it triggers an allergic response.

The process is similar to what happens to people allergic to casein. The body mistakenly identities whey as a foreign invader, triggering an inflammatory response within the immune system.

Whey allergy symptoms are similar to casein allergy symptoms as well. It’s possible for you to be allergic to either – or even both – of these types of milk proteins.

Some people might think they’re allergic to whey, but in reality, they’re just experiencing adverse reactions to lactose. In that case, the only way to know for sure is to see your doctor for a test.

Lactose Intolerance

Unlike dairy allergies, lactose intolerance doesn’t involve the immune system.

It’s actually a digestion issue affecting people who are missing an enzyme called lactase. That enzyme breaks down the sugars (lactose) from dairy products within the intestines. Without it, we deal with digestive issues almost every time after eating dairy.

Unlike dairy allergies, lactose intolerance usually develops when we’re older. Lactase activity within the intestines peaks when we are newborns because we’ve evolved to rely on breast milk.

But something strange happens to many of us with age: we lose that enzyme. This can happen at any stage of life. So you could be a regular milk drinker for decades, then develop an intolerance seemingly out of the blue.


Lactose intolerance is much more common than milk allergies. It’s the norm; not the exception. Believe it or not, but the National Institute of Health estimates that about 65 percent of the global population “has a reduced ability to digest lactose after infancy.”

There’s actually a significant genetic component. Up to 90 percent of people of East Asian descent are lactose intolerant. So are 75 to 80 percent of Africans and African Americans. Contrast this with between just five and 15 percent among people of British ancestry.

Most people become lactose intolerant after age four when many of us lose our ability to make lactase. This makes some sense from an evolutionary perspective because by then we’ve moved past the need to rely on breast milk.

Lactose intolerance can be very uncomfortable, but it isn’t as serious as dairy allergies. Symptoms range from mild to moderate. It usually takes between 30 minutes and two hours for symptoms to appear.

Typical lactose intolerance symptoms include:

  • Bloating
  • Cramps
  • Diarrhea
  • Gas
  • Nausea

There isn’t a cure for lactose intolerance at this time. The easiest way to mitigate symptoms is to just cut back (or eliminate) dairy products from your diet.

The Key Differences Between Dairy Allergy and Lactose Intolerance

We just covered a good bit of information. So here’s a quick rundown of the key differences between dairy allergies and lactose intolerance:

Dairy Allergy

  • Typically develops at a very young age
  • Something you can grow out of
  • Wide range of symptoms and severity (which in very rare cases can be life-threatening)
  • Much less common than lactose intolerance
  • Triggered by dairy proteins
  • Affects the immune system (which reacts as if dairy is a dangerous invader)

Lactose Intolerance

  • Usually develops later in life
  • Can appear at any time
  • Mild to moderate symptoms (almost always indigestion)
  • Affects the majority of the global population
  • More common in certain ethnicities and geographic regions

Moving Forward

If you suspect you may be lactose intolerance or have a dairy allergy, the best thing to do is visit a doctor and get yourself tested. Doctors usually do this through either a blood or skin prick test.

A lot of people don’t realize they’re sensitive to dairy because they’ve had it for as long as they can remember. So what feels like “normal” to them might be less than ideal health.

You can get to the bottom of this by trying an elimination diet. Avoid all dairy products for at least 30 days. Use a journal to track what you eat each day and how you feel. Then you can reintroduce dairy gradually and watch for any differences.

Consuming dairy products isn’t really an option for people who are allergic. But some people who are lactose intolerant enjoy dairy so much they’re willing to put up with discomfort after eating it.

There’s a better way.

Camel Milk: A Viable Alternative

Instead of suffering every time you have dairy products, you could opt for a delicious alternative: camel milk.

Enjoyed throughout the Arab world for thousands of years, camel milk allows you to experience a dairy-like taste without triggering digestive trouble or an allergic episode.

Remember how not all casein proteins are created equal? Beta-casein A1 is the culprit for inflammation and indigestion. Most dairy milk contains a mixture of A1 and A2. But camel milk contains exclusively A2 beta-casein, which has been vindicated as safe for both your digestive and immune systems.

Camel milk also lacks beta-lactoglobulin, the major whey protein found in cow and sheep milk. It contains much less lactose than cow milk, making it a safe alternative for those with lactose intolerance, as a comparison study pointed out.

Knowing the difference between dairy allergies and lactose intolerance is important, but it isn’t enough. The real value is in finding the best way to enjoy the foods you like without compromising your health!

Have you struggled with lactose intolerance or a dairy allergy? If so, what have you tried to address it? Would you consider camel milk as an alternative? Leave a comment below and let us know!