Milk and Lactose: Example of a common food allergy

Milk

Cow’s milk allergy is the most common food allergy. It occurs mainly in infants and children up to 3 years of age. Most children grow out of this allergy (90%). Cow’s milk protein is often the first ‘foreign’ protein given as a replacement for breast milk.

About 5-15% of infants show symptoms of cow’s milk allergy. But in 2-3% this is also confirmed. This overestimation is caused by lactose intolerance. In the case of lactose intolerance, the digestion of lactose (a sugar in milk) does not proceed properly. The symptoms that occur in the intestines are similar to those of food allergy. There is a big difference between cow’s milk allergy and lactose intolerance. 

• milk powder;
• (dry) milk solids;
• milk derivative, whey (powder);
• butter;
• butter concentrate;
• butter oil;
• butter (powder);
• lactoval;
• recaldent (in chewing gum);
• Various protein fractions are used as ingredients: casein, caseinate, whey protein, serum albumin, (α-)lactalbumin, (ß-)lactoglobulin, lactoperoxidase, lactoferrin;
• milk types;
• chocolate milk;
• buttermilk;
• biogarde;
• kefir;
• quark;
• sour cream;
• crème fraîche;
• sour cream;
• (half) cream;
• whipped cream;
• (melted) cheese;
• cheese spread;
• custard;
• curd;
• yoghurt;
• porridge;
• pudding;
• butter;
• ice cream;
• yoghurt drink;
• dairy soft drink;
• whey protein based soft drinks.

Symptoms milk allergy: Most children with cow’s milk allergy experience 2 or more symptoms in 2 or more organs. Common reactions include: skin symptoms, gastrointestinal symptoms and, to a lesser extent, respiratory symptoms. Anaphylactic shock also occurs after milk consumption following a trace of milk (a dirty spoon). The symptoms may appear within minutes to an hour after drinking cow’s milk. Reactions that appear after hours are called delayed reactions. Sometimes symptoms do not appear for days. These late reactions usually only cause symptoms of atopic eczema and intestinal problems such as constipation. These reactions are usually mild. Mothers need not omit every trace of milk from their diet. These traces are too small to be an elicitor in breast milk.™ 70% of (somewhat older) children with CMA can tolerate highly heated milk products. Points of attention:

• Lecithin is usually added as a powder; in almost all cases, this is spray-dried onto whey powder (which therefore contains milk protein);
• Flavourings may contain milk protein as a carrier;
• Some types of margarine contain milk protein;
• Bread improver may contain milk protein;
• Lactose always contains traces of milk protein;
• Meat and fish products may contain milk proteins as a binding agent;
• Pre-packaged salmon may contain transglutaminase (a milk constituent);
• Milk protein may be present in mashed potatoes;
• Lactic acid/lactate is not prepared from milk and does not contain milk protein;
• Think of the fat used for baking and frying;
• Cocoa butter is the fat from the cocoa bean and does not contain milk;
• Milk can be used in the clarification of e.g. wine;
• Do not specify here: soya milk, coconut milk, oat milk, almond milk and rice milk.

Lactose

Lactose is milk sugar. Legally, this substance falls under milk. It is not a legal requirement to declare lactose separately, but it is desirable. 
Lactase is responsible for breaking down lactose into smaller pieces of sugar. These smaller pieces can then pass through the intestinal wall. If there is too little lactase, this passage cannot take place. 
The lactose is then broken down by bacteria. In the process, gas is produced. This causes abdominal pain, flatulence and diarrhoea after consuming a regular serving of milk products.Examples of ingredients and products that (may) contain lactose: 

• Milk protein always contains lactose; see text under milk.

Bacteria in the intestines break down lactose and form gases in the process. The gas production in the intestines causes abdominal pain, flatulence and (frothy) diarrhoea after consumption of a normal portion of milk products.

• Hard Dutch cheese contains virtually no lactose due to the ripening process; processed cheese, cream cheese, mould cheese and fresh cheese such as cottage cheese do contain lactose;
• Lecithin is usually added as a powder; this is in almost all cases spray-dried onto whey powder (which contains milk protein, therefore lactose);
• Some types of margarine contain lactose;
• Bread improver may contain milk protein, i.e. lactose;
• Lactate/lactic acid is not prepared from milk and does not contain lactose;
• Lactitol (sweetener) is made from lactose, but is fully converted and therefore does not contain lactose.