Lots of people are lactose intolerant – about 10% of the population, in fact. If your favourite smoothie is leaving you with unpleasant side effects, what can you do about it?
What is lactose intolerance?
Lactose intolerance occurs due to an insufficient production of lactase, the enzyme produced in the small intestine that breaks down lactose (the main, naturally-occurring sugar in milk and dairy products).
If a person who is lactose intolerant consumes more dairy than their lactase levels can process, lactose can accumulate in the large intestine.
The job of breaking down lactose is left to your large intestine’s gut bacteria, which produces a range by-products during the process, including lactic acid. The build-up of lactic acid is what causes the classic symptoms of lactose intolerance – cramps, nausea, flatulence and diarrhoea.
Lactose intolerance develops with age
Milk is a primary food source for infants and children, and the levels of lactase production are highest at a young age. The production of lactase declines with age (from about two years old), however lactose intolerance tends not to appear until later in life.
Some estimates suggest that 75% of the worldwide adult population will experience lactose intolerance as some stage.
Managing lactose intolerance
Reducing your portion size is a good first step. Try to eat lactose-containing foods but in smaller serves, distributing your dairy throughout the day (instead of eating it all at once) and eating it with other foods. Many people with lactose intolerance can still consume some dairy, just in smaller amounts.
You may wish to try some ‘lactose free’ products, in which the lactase is already broken down.
If your dairy intake is reduced, it’s important to make sure you’re still receiving adequate amounts of key nutrients like calcium in your diet. Non-dairy sources of calcium include leafy greens, broccoli, chia seeds, flaxseeds, sesame seeds, calcium-enriched soy products and quinoa.
There are also lactase enzyme supplements in the market which can be taken before a meal to help with the digestion of dairy products.
Get professional advice
This information is general in nature. Basing a diagnosis on symptoms alone may be misleading as digestive symptoms can occur for a range of reasons other than lactose intolerance. It is always best to speak with your GP or dietitian about what is the right treatment for you. Expert advice is especially important for children who have symptoms of lactose intolerance.
- ‘Chemistry, 2nd Edition’ (2012) by Blackman, Bottle, Schmid, Mocerino and Wille
- ‘Lactose Intolerance’, Dietitians Association of Australia website
- ‘Lactose Intolerance’, U.S. National Institute of Diabetes and Digestive and Kidney Diseases website