People have used the terms “allergy” and “intolerance” interchangeably for a long time. Today we’re breaking down the answer to a common question: is being lactose intolerant the same as having a dairy allergy?
The short answer: no.
The long answer? Still no, because food allergies, intolerances, and preferences have a biological difference and therefore result in different types of reactions in different people. Simply put, a dairy allergy (sometimes called a milk allergy) causes an immune system reaction, whereas an intolerance does not.Milk (and dairy in general) is one of the eight major allergens that currently have specific labeling requirements under the United States’ Food Allergen Labeling and Consumer Protection Act of 2004 – and with good reason. A dairy allergy is one of the most common allergies, particularly in young children.
According to WebMD, as many as 2 in every 100 children under 4 years old are allergic to milk. On top of that, Akash Goel, MD, an assistant professor of medicine in the gastroenterology and hepatology division at Weill Cornell, says approximately 60-70% of the general population is lactose intolerant (and that number is actually over 80% in some parts of the world).
| Lactose Intolerance | Dairy Allergy |
| Occurs when someone is missing the enzyme lactase that helps digest lactose, a sugar found in milk and dairy products. | Occurs when someone has an abnormal immune system response to milk, often cow’s milk, and related dairy products. |
| Causes digestive reactions that include, but are not limited to, bloating, gas, stomach cramps, nausea, vomiting, and diarrhea. | Causes immune reactions that include, but are not limited to: hives, wheezing, itching/tingling/swelling around the lips or mouth, stomach upset, vomiting, or anaphylaxis (a potentially life-threatening reaction that impairs breathing and can cause shock). |
| Onset of symptoms can occur 30 minutes to 2 hours after consuming milk or dairy products. | Onset of symptoms can occur immediately (within minutes to hours of exposure) or with a delayed response of 48 hours up to even a week after ingestion. |
| Most commonly found in adults and children over the age of 5. |
Most commonly found in young babies and children under 5 years old. |
| People who are lactose intolerant can reduce symptoms by taking lactase enzyme supplements before eating dairy and buying lactose-free milk products. | People with a milk allergy should avoid dairy products at all costs. Repeated exposure will not necessarily reduce symptoms. |
**Table sources: Cleveland Clinic, ACAAI, Nestle Health, and AllergyRI**
While being lactose intolerant and having a milk allergy are not the same thing, the physical reactions to both are deeply unpleasant. Foodservice workers can protect themselves and the customers who dine with them by ensuring they understand where dairy shows up in their kitchens and by following best practices for preventing cross contact.
