Allergy to cow’s milk protein:
In cow’s milk allergy, the body’s immune system overreacts to milk proteins either by producing allergy antibodies (IgE), by activation of inflammatory cells or by a combination of these. Each time you eat food containing milk proteins, the immune system reacts allergically, resulting in release of mediators such as histamine, or by a T-cell mediated inflammatory response. Histamine is released from several locations throughout the body and causes symptoms such as diarrhoea, vomiting, stomach pains or skin symptoms (urticaria, eczema).
Cow’s milk contains over 25 different proteins which can cause reactions in individuals allergic to milk. Some people are allergic to just one of them, whilst the majority are allergic to several. Milk from other mammals such as goats, horses and buffalo contain many of the same proteins, such that most individuals allergic to cow’s milk have to avoid milk from all other mammals. In exceptional cases there are individuals who can tolerate milk from mammals other than cows. You cannot be allergic to human breast milk, but if the mother uses cow milk in her diet, the cow’s milk proteins can be transferred to the child via the breast milk and sensitise - and possibly cause symptoms - in the child.
Symptoms:
The symptoms suffered by those with cow’s milk allergy vary amongst individuals. They may be mild and harmless for some, whilst for others even small quantities of milk can lead to a severe allergic reaction. Gastrointestinal symptoms are quite common, whilst itching in the mouth and throat, swollen mucous membranes and breathing difficulties are not quite as common but do occur, particularly in small children. Flare-ups of eczema and urticaria are most common in small children
Who does it affect?
Milk allergy is the most common allergy in small children, due to the fact that cow’s milk is a foodstuff which is often introduced in the infant’s diet at an early stage.
Approximately 2-5% of Norwegian children (0-3 years) have this allergy. The children rapidly develop tolerance and some are free of the allergy after six months, and the majority before the age of 3.
Some live with the allergy for the remainder of their lives. No figures are available for the incidence in young people and adults, but it is believed to be well under 1% of the population.
Diagnosis:
In order to confirm the presence of milk allergy, the doctor examines the patient’s medical history and takes blood samples for allergy antibodies and a skin prick test. In addition, in order to confirm suspected milk allergy, milk should be excluded from the diet for a period of time before reintroducing it. In children who have been without milk for a period of time due to cow’s milk allergy, a controlled provocation with cow’s milk should be undertaken in order to assess whether the allergy has disappeared.
What can replace milk?
- Drinks: Small children should have a milk substitute, especially adapted for allergy sufferers (e.g. Soya-Semp. Prosobee, Profylac, Nutramigen, Pepdite). These are available as a “blue prescription” and may be purchased from pharmacists. Young people and adults can use milk-like drinks such as rice milk, corn milk, soya milk, etc. Rice milk and corn milk are well suited for use in food preparation. It is recommended that alternatives to cordial and fizzy drinks be found as a mealtime drink and thirst quencher.
- In food preparation: Cow’s milk substitute from a pharmacist can be used in most meals. Depending on the nature of the meal, sweet apple cider, water, rice-, soya-, cocoa or corn milk can be used.
- Other dairy products: Neither cheese, margarine, butter, yoghurt, cream, ice cream nor sour cream can be used. There are, however, milk-free margarine and substitute products available for many of the most common dairy products, based on soya, sunflower and other plant-based foodstuffs.
- Nutrients: Milk is an important source of B-vitamins, calcium, proteins and energy. Use of a calcium supplement is often necessary when milk has to be excluded from the diet. The diet should be balanced such that it contains adequate quantities of energy and nutrition. Other fat and protein sources must be added to the diet of small children when milk is removed.
Where do you find milk protein?
Milk is included in many ready-made meals and industrial food products. It is therefore important that one always reads the list of ingredients when purchasing food. The following is a selection of words used in ingredient lists and which identifies that the product contains milk protein:
Crème fraiche, cream, ice cream, casein, caseinate, milk curds, whey protein, margarine, whey, whey powder, cheese, powdered cheese, sour cream, butter, yoghurt, yoghurt powder.
Where an ingredient is produced from milk this should be stated in the declaration of contents. Cocoa butter bears no relation to normal butter and is safe to use.
Other reactions to milk:
Many people will tell you that they are intolerant to milk. Other reactions to milk are called milk protein intolerance and lactose intolerance.
Milk protein intolerance is a term used when allergy cannot be confirmed by laboratory tests, but dietary trials show that the individual is in fact intolerant to milk. Small quantities of milk are tolerated, with reactions occurring after a longer latency period and which are often not as serious as in allergy.
Lactose intolerance is hypersensitivity to lactose. The gut’s ability to break down lactose is impaired due to low concentrations of the enzyme lactase, which is responsible for this breakdown. Lactose intolerance is uncomfortable but not dangerous. Many people can tolerate small quantities of milk. The diet may include yellow cheeses, lactose reduced milk, and often a small quantity of soured milk products. Full-cream milk and brown cheese must be avoided.