What is lactose intolerance?
Lactose is a sugar found naturally in milk and most other dairy products. An intolerance occurs when the body is unable to produce enough lactase, a digestive enzyme produced in the gut, to break down the lactose into a more easily digestible form1.
Lactose intolerance is relatively uncommon, with only 1 in 50 people of European descent having the condition. In the UK, it is more common in people of Asian or African-Caribbean origin1.
There are three main causes2:
Primary – when natural lactase production decreases in response to a decreased intake of dairy products in the diet. This doesn’t usually occur before adulthood and is usually associated with cultural groups where dairy products are not a regular food in the adult diet.
Secondary – a temporary intolerance that is the result of gut damage – from a stomach bug or infection, undiagnosed coeliac disease or a long course of antibiotics, for example.
Congenital – an extremely rare, genetic form of the condition where babies are born without, or with very low amounts of, lactase.
Lactose intolerance may also occur in babies born prematurely because their small intestine is not developed enough at birth. It usually improves as babies get older.
Symptoms of lactose intolerance
The symptoms of lactose intolerance can be similar to those of other conditions, making it hard to identify. However, common symptoms include:
- Stomach pain
- Bloated stomach
- Excessive wind
These symptoms usually occur within 1–3 hours after the lactose containing food has been consumed3.
How do you know if your baby is lactose intolerant?
If you think your baby is having digestive trouble, you should visit your GP, who can help with a diagnosis. They may refer you to a paediatric dietician for more expert care. If your baby is less than a year old, why not try our Baby Symptom Checker? It includes lots of useful tips and a symptom summary to show your GP.
When lactose intolerance is suspected, you may be advised to eliminate lactose from your baby’s diet. You should only do this under the guidance of a healthcare professional, who will provide advice about ensuring your baby still receives all the nutrients they need for healthy development. One nutrient that needs special attention is calcium, a mineral that is usually provided by foods contacting lactose and which can affect normal bone development3.
“Calcium is essential for your baby’s growing bones, so it’s important to pay attention to your baby’s intake if you need to eliminate dairy products.”
If you’re breastfeeding, your baby may need lactase drops to digest the lactose in your breast milk. Usually the enzyme drops are mixed with a small amount of expressed breast milk in a sterile container and then given to the baby from a spoon just before a feed. Eliminating lactose from your own diet won’t help because it is produced by the breasts, and isn’t related to the amount of lactose in your diet. If you think your baby may be reacting to the lactose in your breast milk you should speak to your GP for advice.
As long as the condition is managed and your baby is monitored, lactose intolerance will not affect their development. Identifying it early allows your baby to feel well again and get the nutrients they need for this stage and all future growth. And remember, in most cases, the intolerance may only last 4–6 weeks so it is important to discuss reintroducing lactose with your healthcare professional.
Foods containing lactose and their alternatives
The lactose levels of some common foods:
- Glass of milk (200ml) 9g lactose
- Carton of yogurt (125g) 5.9g lactose
- Fromage Frais (60g) 1.8g lactose
- Cheddar cheese (30g) 0g lactose
- Cottage cheese (40g) 1.2g lactose
- Milk chocolate bar (54g) 5.5g lactose
- Bowl of rice pudding (200g) 7.8g lactose4
The following foods may contain lactose. Check the ingredient list for any of the foods containing lactose listed above3.
- Processed meats and foods, e.g. ham
- Bread and bread products
- Breakfast cereals
Will my baby grow out of lactose intolerance?3
Depending on the cause, your baby may fully recover or be able to tolerate more lactose in the future. For some people, the condition lasts for life.
Your GP or paediatric dietician may recommend a lactose-reduced or lactose-free formula. They may then want to try to reintroduce lactose at some point to test your baby’s reaction and see if there has been any change so keep in touch with your health professional and let them know how you are getting on.
- If you suspect your baby has lactose intolerance, speak to your GP or health visitor. They will guide you in the next steps of identifying the issue and getting your baby back to full health.
- You can also enter your baby's symptoms into our Baby Symptom Checker, which will give you practical advice and a handy symptom summary to discuss with your GP.