Milk Protein Intolerance

Cow's milk protein intolerance

Cow's milk protein intolerance (CMPI) is less common, affecting 2-3% of the population in developed countries. It generally occurs in infancy and usually develops following the introduction of cow's milk based infant formula into the diet. Symptoms of cow's milk protein intolerance are vomiting, diarrhoea and abdominal pain as well as eczema and sometimes breathing problems. CMPI is actually an allergic reaction to the protein found in milk. The immune response involves IgE antibodies and the reaction happens fast. Once a diagnosis has been made the infant is given an appropriate cow's milk free formula. Prognosis is good. 50% of infants grow out of the condition by 1 year of age, 75% by 2 years of age and 90% by 3 years of age. Less than 1% of infants maintain a life- long allergy to milk (Wyllie, 1996).

Other cow’s milk reactions

Some people appear to have different reactions to milk which may take longer to develop and may be IgG mediated immune* reactions rather than the typical IgE mediated allergic* reactions. These reactions can have wide ranging symptoms which can take days to appear rather than being instantaneous. Symptoms can be varied – abdominal discomfort and pain, bloating, diarrhoea, constipation, eczema, asthma and more controversially migraine, ADHD and rheumatoid arthritis.

Symptoms of sinus congestion and excess mucus production are sometimes attributed to a reaction to dairy foods. Anecdotally some people get relief from excluding dairy products from the diet, although there is little scientific evidence to support this.

A milk free/casein free diet (often in association with a gluten-free diet) is sometimes used to treat Autism Spectrum disorder. Some studies have shown improvements in autistic behaviour by excluding cow’s milk from the diet (Knivsberg et al 2002).

* IgE or Immunoglobulin E is a class of antibodies which are part of our immune system. The antibodies are produced by white blood cells in the body to fight infections from bacteria and viruses. IgE is the least common antibody in the blood but is responsible for triggering most allergic reactions. Allergic reactions to foods occur because the body mistakenly reacts to food protein (for example cow’s milk protein or soya protein) treating it as a hostile invader or allergen. The reaction causes the release of inflammatory substances in the body, like histamine, which result in allergic reaction symptoms like diarrhoea, wheezing and itchy red skin.

* IgG or Immunoglobulin G is another type of antibody which attacks bacteria and viruses in the body. It is the most common antibody in the body but appears to have a more minor role than IgE in allergic reactions.