Understanding lactose intolerance

Lactose intolerance is a set of symptoms caused by the body’s inability to digest lactose properly.

Lactose is a naturally occurring sugar found in dairy foods such as cow’s milk and yoghurt. It is normally broken down or digested by an enzyme in our body called lactase, and ends up in the bloodstream as glucose (another term for sugar).

People with lactose intolerance don’t have enough of this enzyme to properly digest lactose, resulting in lactose intolerance.

People with lactose intolerance still produce a small amount of lactase. If you have lactose intolerance, it is not necessary to completely remove dairy products from your diet. Also, the amount of lactose a person can tolerate varies, for example a small amount in a cup of tea may be tolerated but a milkshake may not be. Some dairy foods contain smaller amounts of lactose (e.g. cheese) so you may be able to eat these without symptoms occurring.

Lactose intolerance is more common among Asian, Middle Eastern and Aboriginal and Torres Strait Islander population groups. In Caucasians, approximately 1 in 20 people have some degree of lactose intolerance.

Symptoms include:

  • Diarrhoea
  • Stomach cramps
  • Bloating
  • Excessive flatulence

These symptoms can also be related to many other conditions, so it is always a good idea to discuss your symptoms with a GP before reducing or removing dairy products in your diet.

Smart eating tips for managing lactose intolerance in adults

  • Drink milk in smaller quantities. Most people with lactose intolerance can tolerate ½ cup milk at a time. Full cream milk is generally better tolerated than low fat or calcium enriched milks.
  • Spread lactose-containing foods out during the day and eat them with other foods, rather than eating them all at once
  • Yoghurt is low in lactose as the natural bacteria break it down
  • Hard cheeses (such as cheddar) are low in lactose and can generally be eaten without any symptoms
  • You can buy lactose-free milk which has the lactose broken down already
  • You can buy enzyme drops or tablets from the pharmacy and add to regular milk to make it easier to digest or your doctor may suggest other over-the-counter products
  • Lactose can also be an ingredient in many processed foods such as biscuits and cakes, cheese sauce, cream soups and custards. Check the ingredient list for ingredients such as milk solids, non-fat milk solids, whey and milk sugar
  • Soy products do not contain any lactose and can be a suitable substitute for dairy products, providing they have calcium added

If you are diagnosed with lactose intolerance, an Accredited Practising Dietitian (APD) can help to ensure you are not missing out on important nutrients such as calcium. This is particularly important for children.