Milk Protein Allergy vs Lactose Intolerance

For More Information
Please Contact Us

Milk Protein Allergy vs Lactose Intolerance

A lot of people have stomach issues after eating milk or dairy products and assume they are lactose intolerant or allergic to milk. But, you might be unaware that there is a pretty big difference between lactose intolerance and a milk allergy.

Lactose is the naturally occurring sugar in milk. Carbohydrates, including sugars, are broken down by enzymes in the small intestine so that the nutrients can be absorbed into the blood stream. The enzyme that breaks down lactose is called lactase. At birth, humans produce abundant amounts of lactase to break down the lactose in breast milk. Over the years, lactase production often decreases causing many older children and adults to become lactose intolerant. If you do not have enough of the enzyme lactase to break down lactose, the intact sugar is carried throughout the GI tract which can cause abdominal pain, gas, and distention. With lactose intolerance, often milk can be tolerated in small amounts and is usually better tolerated in more processed forms such as cheese, yogurt, or butter.

On the other hand, food allergies are caused by an immune response to the protein in foods. Where lactase deficiency is extremely rare in infants, a milk protein allergy is more common. Symptoms of a milk protein allergy in infants may include vomiting, blood in stool, fussiness, and poor growth. Breastfeeding mothers may have to remove dairy from their diet to prevent the infant from ingesting the milk protein. In some cases, even small amounts of accidental ingestion of milk products by the mother can cause the infant to react; so, often, formulas that have the milk proteins broken down to the elemental form are used. Up to 80% of children with a milk protein allergy outgrow it by early childhood however sometimes the allergy persists into adolescence or adulthood. People with a true milk protein allergy should avoid all forms of milk.


For more information or help managing your diet, schedule an appointment with Madden Wilson, RDN, our registered dietitian.