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Milk Alergy vs. lactose Intolerance

Milk allergy is often confused with lactose intolerance because people can have the same kinds of things happening to them (like stomach pains or bloating, for example) with both conditions. But they're not related:

Milk allergy

This is like most food allergy reactions. It usually happens within minutes to hours after eating foods that contain milk proteins.

Although it's not common, milk allergies can cause a severe reaction called  anaphylaxis. Anaphylaxis may begin with some of the same symptoms as a less severe reaction, but then quickly worsen. A person might have trouble breathing, feel lightheaded, or pass out. If it's not treated, anaphylaxis can be life threatening.

Allergies to milk (casein allergy, lactalbumine allergy, cow’s milk allergy) are not be confused with lactose intolerance! They are not food intolerances, but true allergies to certain ingredients in milk!

Milk allergies and lactose intolerance are not the same thing. A milk allergy is caused by a malfunctioning immune system. The immune system identifies milk proteins as harmful "invaders" and releases antibodies called immunoglobulin E (IgE) antibodies into your bloodstream. These antibodies then release histamine, which causes milk allergy symptoms.

What Happens With a Milk Allergy?

Food allergies involve the body's immune system, which normally fights infection. When someone is allergic to a particular food, the immune system overreacts to proteins in that food.

People who are allergic to cow's milk react to one or more of the proteins in it. Curd, the substance that forms chunks in sour milk, contains 80% of milk's proteins, including several called caseins (pronounced: kay-seenz). Whey (pronounced: way), the watery part of milk, holds the other 20%. A person may be allergic to proteins in either or both parts of milk.

Every time the person eats these proteins, the body thinks they are harmful invaders. The immune system responds by kicking into high gear to fend off the "invader." This causes an allergic reaction, in which chemicals like histamine are released in the body.

Symptoms of a Milk Allergy.

The release of these chemicals can cause someone to have the following problems:

  • wheezing

  • trouble breathing

  • coughing

  • hoarseness

  • throat tightness

  • stomach ache

  • vomiting

  • diarrhea

  • itchy, watery, or swollen eyes

  • hives

  • red spots

  • swelling

  • a drop in blood pressure

Milk allergy is like most food allergy reactions. It usually happens within minutes to hours after eating foods that contain milk proteins.

Lactose intolerance

Lactose intolerance occurs when the body cannot easily digest lactose, a type of natural sugar found in milk and dairy products.

Lactose is present in almost all dairy products and is normally digested in the small intestine with the help of an enzyme called lactase which splits the disaccharide into two monosaccharides (simple sugars).

What Happens With Lactose Intolerance?

Without this enzyme, or enough of this enzyme, the body does not break down all the lactose into smaller parts for digestion and absorption and as a consequence reaches the large intestine. Here there are bacteria that process the lactase and this leads to the production of various gases. When lactose moves through the large intestine (colon) without being properly digested, it can cause uncomfortable symptoms such as gas, belly pain, and bloating.

Symptoms of lactose intolerance include:

People with lactose intolerance may feel uncomfortable 30 minutes to 2 hours after consuming milk and milk products. Symptoms range from mild to severe, based on the amount of lactose consumed and the amount a person can tolerate.



Bloated stomach (abdomen)

Abdominal pain


Cold sweat

There are people , however, who can experience these symptoms for other reasons than food intolerance. For this reason it is absolutely essential to have a test done by a medical professional, if a person believes they may be suffering from food intolerance

This information has been sourced , in part rom the following sites: How Stuff Works  Kids Health  Food Allergy Solutions   Net Doctor UK  Dietitians of Canada  Food Intolerence Network  Web MD National Digestive Diseases Information Clearinghouse