Undiagnosed or poorly managed Lactose Intolerance can leave people suffering with stomach pain, bloating and diarrhoea amongst other symptoms. Here is a simple guide to what lactose intolerance is, how it is diagnosed, and how is it different from Cows Milk Allergy.
Lactose intolerance is the inability to efficiently fully digest the type of sugar found in milk (of ALL animal types). This is due to a deficiency of the enzyme that breaks lactose down (lactase), which may be an inherited deficiency or an acquired deficiency after any kind of condition that damages the intestines, such as gastroenteritis (this type usually resolves when the gut recovers).
The IBS-type symptoms of lactose intolerance make it difficult to distinguish from conditions such as coeliac disease, crohn’s disease and parasitic disease and if symptoms improve when milk is removed from the diet it could easily be mixed up with Cows Milk allergy. Milk allergy is an allergic response to the PROTEIN in milk and babies who react when weaned onto milk should be tested.
Diagnosing Lactose Intolerance
Two formal tests are commonly used:
- The lactose tolerance test measures blood glucose after ingesting lactose (healthy people will bring the blood sugar back down when lactase gets to work but the blood sugar of lactase-deficient people will remain raised for longer).
- In the Hydrogen breath test the presence of hydrogen in the breath after ingesting lactose shows that undigested lactose has been fermented in the colon (which is not normal).
Lactose Intolerant Diet
An entirely lactose-free diet is rarely necessary but individual tolerance needs to be established by gradually reintroducing small amounts of lactose once symptomatic relief is achieved. The main dietary source of lactose is milk of all animal types (lactose content 8-10g/200mL), followed by cream, ice cream, yoghurts (3g per small pot), cottage/cream cheese and fromage frais. Lactose-free, soya or other non-dairy alternatives should be substituted but ensure that they are fortified with calcium.
Most cheeses have very little or no lactose (less than 0.1g per 100g) and can be safely tolerated. A simple way of checking is to look for carbohydrates (of which sugars) on the label – there shoudn’t be any sugar other than lactose in most cheese so here is where you will find it.
Lactose may also be found in food where milk ingredients are added. These have to be declared on labels but common sources include bread and baked goods, some breakfast cereals, instant potato, margarine, milk chocolate.
If you think you may be lactose intolerance try to get tested using one of the proper scientifc tests mentioned. Careful dietary management can relieve debilitating symptoms and if needed Lactase supplements can be used to enhance lactose digestion. Calcium and Vitamin D supplements may also be needed if dietary intake is compromised.