Lactose intolerance Mate reihuka

Lactose is a natural sugar which is broken down in your small intestine by an enzyme called lactase. Some people do not make enough lactase to break down the lactose. When this happens, the lactose passes through to your large bowel (colon). The bacteria that live in your large bowel break down the lactose. This causes symptoms.

Lactose intolerance is not common in pēpi. Most lactose intolerance starts during childhood or the teenage years.

People sometimes become lactose intolerant after having a tummy bug (gastroenteritis). It can also happen due to damage to the small intestine caused by diseases such as coeliac disease. This type of lactose intolerance usually disappears once the infection or disease has been treated and your gut has healed.

Coeliac disease

It is more common in people who are:

• Asian
• Middle Eastern
• from Mediterranean countries
• South American
• African.

It may also be more common in Māori and Pacific peoples.

When people who are lactose intolerant eat or drink foods containing lactose, they may experience:

• bloating (tight or swollen tummy)
• excessive farting
• tummy cramps and rumbling
• runny poos (diarrhoea)

These symptoms usually begin 30 minutes to 2 hours after eating or drinking lactose-rich foods.

If you think you might be lactose intolerant, talk to your healthcare provider. They will ask you about your symptoms and your health and lifestyle.

If it is possible that you are lactose intolerant, you will need to avoid lactose-rich foods for 2 to 4 weeks to check if your symptoms go away.

Lactose-rich foods include:

• fresh cow, goat and sheep milk
• powdered, evaporated, and long-life milk
• buttermilk
• sweetened condensed milk
• yoghurt made from animal milk
• custard
• ice cream
• creamy pasta sauces and white sauces
• sour cream and crème fraîche
• soft unripened cheeses such as ricotta, cottage, cream cheese and mascarpone.

You will not need to avoid bread, biscuits or cake that contain milk. The amount of milk in these foods is not enough to cause symptoms.

If your symptoms do not get better after 4 weeks, then you are not lactose intolerant. You should start eating normally again and see your healthcare provider.

If your symptoms get much better after 2 weeks, then you know lactose is a problem.

There are laboratory tests available to diagnose lactose intolerance but most of these tests are not very reliable. The most reliable test is called a breath hydrogen test. It is not publicly funded, and some people will get a negative result even though they are lactose intolerant.

Milk allergies are different

Lactose intolerance is not the same as a milk allergy.

A milk allergy is an allergic reaction to the protein in milk. It is more common in pēpi and young tamariki than adults. It usually disappears as tamariki grow older.

If you have a milk allergy, you need to avoid all animal milk and milk products. If you have a lactose intolerance, you can usually eat hard cheese and small amounts of milk and yoghurt.

You should not avoid all milk and milk products. These foods contain nutrients such as protein and calcium that help to keep your body and bones healthy.

Even if you are lactose intolerant, regularly eating small amounts of lactose is good for you. This is because your gut contains bacteria that can also break down lactose, and eating small amounts of lactose can encourage the activity of these bacteria and improve your tolerance.

Whole milk (dark blue top) is usually easier to tolerate than trim milk (green top). This is because it contains less lactose and more fat.

Find your tolerance levels

Different people can tolerate different amounts of lactose.

To work out how much you can have, start drinking small amounts of milk. Drink the milk on its own and not with other foods. 

Start with ½ cup a day for 3 to 4 days. If you cope with this, try having ¾ cup of milk a day for a few days, and so on. This will help you understand how much lactose your body can tolerate.

Reducing lactose in your diet

The following tips will help you lower your lactose intake and make sure you get enough protein and calcium.

Use lactose-free milk instead of regular milk

You should be able to cope with a small amount of regular milk in tea and coffee or a small glass of regular milk at the same time as having other food. If you want to have more than this, use a lactose-free milk.

There are many different kinds of lactose-free milks. These include:

• lactose-free cow's milk
• soy milk
• almond milk
• oat milk.

You can buy these in supermarkets.

Lactose-free cow's milk and soy milk are the best options. They have a lot more protein than other plant milks. If you choose soy or other plant milks, make sure they have added calcium with at least 120 mg calcium per 100 ml milk.

Use lactose-free yoghurt instead of regular yoghurt

Some people with lactose intolerance can eat regular yoghurt. This is especially true if the yoghurt contains live bacteria and is higher in fat, such as a Greek yoghurt. The bacteria break down some of the lactose in the yoghurt. They also supply lactase, which helps your body break down the remaining lactose.

If you cannot tolerate regular yoghurt, use a soy, coconut or almond yoghurt. You can buy these in the supermarket.

Use sorbet or lactose-free ice cream instead of regular ice cream

Many different sorbets (flavoured ice), coconut or soy-based ice creams are available in the supermarket. These are high in sugar, so keep them for an occasional treat.

Use hard and semi-hard cheeses instead of soft, unripened cheeses

Hard and semi-hard cheeses contain very little or no lactose. These include:

• cheddar
• edam
• feta
• mozzarella
• gouda
• parmesan.

Brie and camembert also contain very little lactose.

Avoid haloumi cheese and soft, unripened cheeses that come in a tub. These contain small amounts of lactose and include:

• ricotta
• cottage cheese
• cream cheese
• mascarpone
• crème fraîche.

You should only eat these in small quantities, such as 2 tablespoons or less.

Have food and drinks that contain lactose with other foods

This makes the lactose pass through your gut more slowly, giving the lactase you do have more time to work.

Lactase enzyme supplements

You can get lactase enzyme supplements from a pharmacy. These are available as tablets or drops.

You take the tablets before having lactose-rich food. You can add the drops to animal milk or milk products.

If you can tolerate dairy products in small amounts, you do not need a lactase supplement. They are expensive so if you do find them helpful, you might like to keep them for special occasions or when eating out.