Food hypersensitivity’ is the appropriate medical term used to describe any adverse reaction to a particular food. Cow’s milk protein allergy and lactose intolerance are the two main hypersensitivities relating to dairy. Although they are often confused, they are two very distinct conditions that require expert diagnosis in order to avoid unnecessary or inappropriate changes to the diet.
Lactose intolerances occur in adults who have low levels of the enzyme needed to digest the naturally occurring sugar in milk, known as lactose. This can cause digestion problems if too much lactose is consumed. It is often believed that lactose intolerance is a very common condition but in Ireland and other northern European countries only about 4-5 % of the population are affected.
Depending on the level of tolerance, most people can consume some lactose – typically a daily amount of 12-15 g. A 200 ml glass of milk contains approximately 9-10 g lactose, while the amounts in yogurt and cheese is considerably less – 5.9 g in 125 ml pot of plain whole yogurt and 0.03 g in 25 g of cheddar cheese.