Up to one in seven people in the UK is thought to be lactose intolerant.
Lactose intolerance (LI) is the body's inability to produce enough of the enzyme lactase in the digestive tract. Without it, lactose (the natural sugar in milk and other dairy products) cannot be digested properly.
Two types of lactose intolerance occur in children:
Secondary (or transient) lactase deficiency is caused by damage to the small intestine. This is commonly the result of gastroenteritis in babies and small children. The infection causes the lining of the gut to swell which erodes the lactase enzyme. This can cause persistent diarrhoea in children, lasting up to a month unless they are given lactose-free milk formula.
Surgery, injury and other disease can also lower levels of lactase production.
Secondary lactase deficiency can last as little as a few weeks or can be permanent.
Congenital lactase deficiency is extremely rare and occurs when a baby is born without enough lactase to digest breast milk. Babies suffering from this must be given lactose-free formula and will be lactose-intolerant for life. For a child to inherit this condition, it must be passd down by both parents.
After the age of two:
Primary lactose intolerance starts after infancy and develops gradually. The body produces less lactase after the age of two, but this is a gradual process so the symptoms of LI do not usually appear until an older age. This type of LI has a genetic link, so can be inherited.
What are the symptoms of lactose intolerance?
- Diarrhoea is the most common symptom
- Bloating and wind
- Stomach pains
- Stomach growling and gurgling
What can I do if my child is lactose intolerant?
Firstly, get a clear diagnosis. Contact your GP who can refer you to a specialist if necessary.
Inform yourself about foods that contain lactose so you do not cut out important food groups unnecessarily.
If your child has LI, look out for dairy-free ranges such as Lactofree®, made with normal cow's milk that has been filtered to remove most of the lactose. That means your baby or child does not miss out on the other benefits of dairy products.
What's the difference between lactose intolerance and milk allergy?
LI should not be confused with milk allergy - it does not involve the immune system and won't usually produce a sudden or dangerous reaction.
Milk allergy is the most common food allergy for babies and children in the UK, affecting 2-7% of babies aged one year or less. It is the immune system's overreaction to one or more of the proteins found in milk. Most children will outgrow their milk allergy.
Produced with help from Lactofree® and paediatric allergy specialist Dr Adam Fox.