Cow’s milk contains over 25 different molecules, which have the
potential to elicit an allergic reaction. No wonder milk is repeatedly
ranked among the top eight offenders for food allergies!
In fact, many doctors, scientists, and health specialists recommend going dairy free as an initial test when a food allergy is suspected.
Milk allergy is caused when the immune system (IS) reacts against one or more of the proteins found in milk. This happens due to the lack of the IS to learn to recognize milk proteins as being harmless. Hence every time milk is ingested in a subject, the IS is falsely alerted that a harmful body has entered the body and tries to eliminate it as if it were a bacteria, or a virus or a harmful chemical. The IS through specialised cells releases granules containing toxins, and it is these toxins that make persons with milk allergy to suffer the symptoms associated with food allergy, see Figure 1 below. Milk allergy is often muddled with Lactose Intolerance (LI). Although their symptoms sometimes are confused with each other's they are two different conditions. While the former is a reaction by the IS, LI is caused by inadequate amount of lactase enzyme to break down lactose. Read about Lactose Intolerance and also how to differentiate the symptoms of both to avoid confusion.
What causes an allergy?
The cause of an allergy is the inappropriate or exaggerated reactions of the IS to a variety of substances. The function of the immune system is to recognize foreign proteins (antigens) on the surfaces of micro organisms and to form antibodies (also known as immunoglobulins). When the IS next encounters the same antigens, the antibodies interact with them, leading to destruction of the micro organisms. In allergies, a similar immune response occurs, except that the immune system forms antibodies against harmless substances - because these allergens, as they are called, are misidentified as potential harmful proteins. The inappropriate or exaggerated reactions seen in allergies are termed hypersensitivity reactions. See a list of products and allergens that cause allergic reaction. Food preservatives and colourings (E colours, e.g. E120) may also be a great factor that may cause severe allergies. See also full review onFood Allergy.
There are many protein allergens in cow's milk that cause allergic reactions. Casein and whey are the two main components. The curd that forms when milk is left to sour, is called casein. The watery part which is left after the curd is removed, is called whey.
Figure 1: Free IgE antibodies (green) cleave to food antigens (red stars) e.g. milk proteins. This cleavage forces the IgE ab to coat the mast cell signalling a danger. The mast cell releases granules of chemical toxins. These granules burst and release these potent chemicals which bring on the allergy attack.
Casein accounts for 80 percent of the protein in milk and is the most important allergen found in cheese. The harder the cheese, the more casein it contains.
Whey accounts for the other 20 percent of milk. It consists of two main allergenic proteins - alpha-lactalbumin and beta-lactaglobulin.
How Common is Milk Allergy?
Milk allergy is more common in children than in adults. It is estimated that 2 to 5 % of infants develop milk allergy. Up to 60% of infants allergic to cow’s milk will “outgrow” the allergy by the age of 4 and 80% by the age of 6. However it still leaves a significant percentage of milk allergy sufferers into adult hood. Moreover, it is possible for adults to develop a milk allergy with no childhood history of allergies. Another interesting fact, symptoms associated with milk allergy have the potential to morph over time. One study followed a group of milk allergic children and found that at the beginning of the study most of the children had primarily gastrointestinal symptoms (vomiting, diarrhoea), but by the end of the study, many had switched over to respiratory symptoms such as wheezing.
What are the symptoms of milk allergy?
An allergy is caused when an allergen (for a list of other common allergens click here) enters our body system. The symptoms of a milk protein allergy fall into 3 types of reactions:
- Skin Reactions:
* Itchy red rash
* Swelling of lips, mouth, tongue, face or throat
* Allergic "Shiners" (black eyes)
- Stomach and Intestinal Reactions:
* Abdominal pain and bloating
* Diarrhoea (usually very runny)
- Nose, Throat and Lung Reactions:
* Runny Nose
* Watery and/or Itchy eyes
* Shortness of Breath
The milk allergy symptoms are not only restricted to people suffering from milk allergy. Many other people can show these symptoms to basically any other immune reaction. This could be from a simple mosquito bite to a drug reaction such as penicillin. Common food allergies, all with similar symptoms include sea shells, peanuts, banana and eggs.
Treatment for milk allergies?
Currently the only 100% successful treatment for milk allergies is total avoidance of milk proteins. Infants who develop milk allergy, usually outgrow the condition. However, if the infants are breastfed, the lactating mothers are given an elimination diet. If symptoms are not relieved or if the infants are bottle-fed, milk substitute formulas are used to provide the infant with a complete source of nutrition. Milk substitutes include soy milk, rice milk, and hypoallergenic formulas based on hydrolysed protein or free amino acids.
As for older children and adults, one should watch the recipes of dishes consumed in restaurants or at parties (see a list ofhidden milk products). Proteins in milk and/or food may be the cause of the allergy, but this may be minimised if not eliminated by digestive enzymes. These digestive enzymes break down proteins in the intestines before reaching our blood supply and hence disallowing the protein to act as an allergen. Examples of products that do this are Spectrumzyme and Digestaid - found in the products section.Enzymes to the Rescue, is a medical report describing how digestive enzymes are helping people with food and milk allergy.
Antihistamine drugs are very effective in calming down the reactions caused by the allergy, such as itching. Antihistamine is a sedative drug therefore it sends the user in deep sleep. This is to the advantage of the sufferer as it stops the person from itching in cases of skin eczema. Other drugs, such as sodium cromoglycate and corticosteroid drugs can be take regularly to prevent symptoms from developing. Creams containing corticosteroids are useful for eczema but prolonged use of them may damage the skin.
There are a number of other milks that are available that may be substituted for cow's milk when baking or cooking. The type of substitute used will depend on the type of food it is used for.
Rice milk is good for drinking and putting on cereal. It can also be used when baking or as a thickening agent.
In some recipes water, broth, or juice can be substituted for the cow's milk.
Sometimes, a milk allergic person can use goat's milk or soy milk. Both of these milks, however, are also very allergenic. In fact, many people allergic to cow's milk are also allergic to goat's milk.
The Milk Alternative page provides with more details.
Without milk in the diet, the nutritional needs of the body need to be met. The first concern is to get enough calcium in the diet (visit the Milk Alternative page for calcium replacement). The recommended daily allowance of calcium depends on the age of the individual. Excellent sources of calcium include green vegetables (broccoli, collard greens, turnip greens, and kale), fish with soft, edible bones (salmon and sardines), and seafood (oysters and shrimp).
Calcium can not be absorbed without Vitamin D. Sources of Vitamin D include eggs, liver, and sunlight.
A milk-free diet should be monitored by a dietician to ensure a nutritionally adequate diet.