Cow’s milk can be allergic

Dr Nandan Joshi

Food is our biggest ally in the quest for good health. Its effect on health and wellbeing is proverbial but it becomes a downside when an individual develops allergy towards a food. The onset of food allergies is surging as people experience adverse reaction(s) after consuming certain food items like peanuts, finned fish, shellfish, milk, egg, wheat, soy and seeds. Some children are especially allergic to foods like milk, egg, wheat, and soy. One common food allergy which children in the age group of zero to three years can be affected with is cow’s milk protein allergy (CMPA).

CMPA explained

Cow milk allergy is an adverse response by the body’s immune system to a protein present in cow’s milk or milk products.  In India, cow milk is quite popular, as it is perceived to be lighter than buffalo milk that has more fat content than cow milk. Because of this reason, people think it is more easily digestible than buffalo milk.

Hence, it is perceived safe for newborn babies and is introduced either as part of mother’s diet when she is breastfeeding the baby or as a complementary food when it is initiated. Globally, around 2 to 3 per cent of the babies are affected by this allergy. It manifests itself as an overreaction of our immune system. Our body’s immune system mistakes the common proteins present in this milk as “dangerous”. The immune system initiates response mechanism to counterbalance the “dangerous protein”. The body’s misplaced response is the cause of the symptoms felt by a individual when he or she consumes milk. If a baby is allergic to cow milk protein then it is very likely that the baby will react to buffalo, goat or sheep milk as well.

Mistaken for lactose intolerance

The symptoms of cow milk allergy and lactose intolerance are quite similar and it is easy to mistake one for another. However, these two are very different conditions. Lactose intolerance is the body’s inability to digest a sugar present in the milk called lactose. Lactose intolerant people can’t process lactose because of lack of an enzyme, lactase. The immune system is not involved so there is no allergy symptom triggered by the body. 

Lactose intolerance symptoms include bloating, abdominal pain, flatulence, or diarrhoea as these are the initial markers for lactose intolerance. The skin or the respiratory tract is not impacted by it.

The main difference between cow milk allergy and lactose intolerance is that in cow milk allergy, our immune system overreacts to one or more proteins in cow’s milk while in lactose intolerance our body cannot digest lactose which is the sugar component present in milk. 

Impact on newborns

The burden of cow milk protein allergy is long term as it influences the baby during her/his first 1,000 days, which is a critical window for the overall growth and development of a baby.  The first 1,000 days is the term coined to denote the period of rapid growth and development of the baby, both in the womb as well as after birth. It is the time when there is expansion in growth and fast-tracked development of the brain, digestive and immune system. It is crucial to that every child has access to best nutrition during the first 1,000 days to ensure her/her long term health.  The symptoms experienced by a baby due to CMPA like diarrhoea and vomiting for a long period, coupled with delayed diagnosis, lead to loss of weight among babies. Sometimes they present with failure to thrive.

Management of allergy

Eliminating cow’s milk and milk products from the baby’s diet, who is on complementary feeding, and eliminating the same from the mother’s diet for babies who are on exclusive breastfeeding is the first step in management of CMPA. However, elimination of cow’s milk needs to be compensated by giving right nutrition at this point otherwise the babies do end up losing weight and fall below their growth curve. There is availability of extensively hydrolysed and amino acid formulas in the Indian market which have proteins which are easier for babies to digest who are allergic to cow’s milk.

Symptoms

CMPA typically affects these systems — skin, digestive and respiratory. Skin symptoms include rashes, hives or puffiness near the areas of lips, mouth or eyes. Digestive symptoms can be vomiting, pain in abdomen, diarrhoea, colic pain, constipation and blood in stool. Symptoms of respiratory system being affected are wheezing, chronic coughing and runny nose. Diagnosis can be difficult since the symptoms don’t follow straightaway all the time. The body may or may not respond immediately to the protein present in the cow’s milk. In certain situations, allergic reactions are delayed making the diagnosis difficult. An immediate reaction could be vomiting, wheezing or a skin rash which can present within 2 hours of ingestion of food. And delayed reaction could be diarrhoea or constipation or colic which may take few days to present.

— The writer is head, nutrition science & medical affairs, Danone India