Lactose intolerance: What you need to know

If you think you’re lactose intolerant, you’re not alone!  It is estimated that around 70% of the world’s population is lactose intolerant. It is more prevalent among people of African and Asian descent, reaching up to 100% in some countries.


Lactose is a sugar found in dairy products, made up of 2 smaller sugar molecules, glucose and galactose. In order to be absorbed, the body must break the link between glucose and galactose with the help of an enzyme, lactase, which is produced by cells in the wall of the small intestine. However, some people produce little or no lactase, particularly in adulthood. Lactose intolerance can be congenital (from birth and more severe) or caused by non-persistent production of the enzyme (cessation or reduction of lactase production after childhood). It can also be temporary, following a gastrointestinal infection for example.

Lactose intolerance can therefore vary from one individual to another, as can the amount of lactose consumed, which can cause symptoms. 

It should be noted that lactose intolerance is NOT an allergy. A milk allergy is characterized by an immune response to the protein in cow’s milk, not to lactose.


When a lactose-intolerant person consumes lactose, or too much of it to be able to digest, a number of symptoms can occur. Undigested lactose reaches the large intestine. As it is a sugar, it creates a call for water and can cause diarrhea. In the colon, it is fermented by intestinal bacteria, causing bloating, pain, cramps, flatulence and nausea. These symptoms generally appear fairly quickly after lactose consumption, within 30 minutes to 2 hours.


Lactose intolerance can be tested by following a dairy-free diet for 2 to 4 weeks. Your doctor can then confirm the diagnosis by performing a hydrogen breath test.


There are many ways to reduce the effects of lactose intolerance.

  1. Evaluate your tolerance level and do not exceed it: Fermented dairy products often contain less lactose, so some people will be able to tolerate certain cheeses or yogurts, whereas they may have more difficulty with milk or ice cream. All you have to do is identify the products you can tolerate, the quantities you can consume, and make sure you don’t exceed them.
  2. Lactase suppléments: It is possible to take lactase supplements before consuming dairy products. Dosages vary according to intolerance and the amount of dairy products you wish to consume. These supplements should be taken just before consuming dairy products, and should be consumed only as needed.
  3. Minimize or eliminate consumption of dairy products: You can consume dairy products identified as lactose-free, and there are many commercially available lactose-free milk, cheese and yoghurt alternatives. Many plant-based alternatives are now available, such as milks, yogurts, cheeses, creams and ice creams made from soy, oats, coconut, almonds among others.

If you choose to minimize or eliminate dairy products, it’s important to make sure you’re getting enough calcium. You should verify that the plant milks you choose contain calcium – most do, but some don’t. You can also increase your intake of calcium-rich plant-based foods such as green vegetables, almonds, tofu, chia seeds, sunflower seeds, sesame seeds and tahini, dried figs…


To learn more or to obtain an intervention plan adapted to your needs, talk to your doctor or make an appointment with our nutrition team through your quatuor care pod.

*The information contained in this factsheet does not replace the advice of a health professional and is provided for information purposes only.