Lactose Intolerance

What Is Lactose?

Lactose is the sugar that is found in milk products from any mammal.  It is a double-sugar made up of two smaller sugars (glucose and galactose).

What is Lactose-Intolerance?

Normally, lactose is broken down to these two smaller sugars by the enzyme, lactase.  Lactase is produced by the villi that line our small intestine, however the production of lactase can be temporarily decreased by damage to the small intestine, such as the result of a gastro infection.  Our production of lactase can also gradually decrease as we get older.  In this situation, such people have a lactase insufficiency and therefore permanent lactose intolerance.  Most people still produce a small amount of lactase.

Without enough lactase enzyme, the lactose sugar is not digested normally in the small intestine.  Instead, it passes to the large intestine where it is fermented by bacteria.  This fermentation can cause the common symptoms include diarrhoea or loose motions, wind and abdominal bloating and discomfort.

What Can I Eat on a Lactose-Free Diet?

The degree and severity of symptoms depends on the level of lactase insufficiency.  If you are still producing some lactase enzyme, you can still continue to include lactose in small amounts in the diet as tolerated. For example,  milk in tea and coffee throughout the day may be tolerated; however to drink a full glass of milk would cause symptoms.  This is because the body can often be producing very small amounts of the lactase enzyme, however not enough to cope with a large load of lactose at once.

Dietary Advice

Avoiding dairy products is not the answer to lactose intolerance. Dietary therapy includes:

  1. Choose lactose-free varieties where possible.
  2. Lactose intolerance is often dose-related.  Therefore having smaller quantities more often over the day may be better tolerated

For a full description of all of the foods that can be enjoyed on a lactose-free diet, you should consult an Accredited Practising Dietitian who specialises in gastrointestinal nutrition. Find out more about making an appointment to see a dietitian.

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