What is lactose intolerance?
Lactose intolerance is the inability to digest most of the lactose in food taken in, due to a shortage of the enzyme lactase.
Lactose is a dissacharide sugar present in milk (also called “milk sugar”), which means it is made up of two monosaccharides (glucose and galactose).
The enzyme lactase is normally produced in the small intestine and functions to separate the two sugars from each other. Lactase breaks down the lactose, the main sugar in milk, into two smaller sugars glucose and galactose to be absorbed in the bloodstream.
Important lactose intolerance facts
- Lactose intolerance is the most common disorder in the world
- Lactose intolerance has several grades of severity, from not producing many symptoms to being very severe and producing very uncomfortable symptoms
- There are various tests that can be conducted to test for lactose intolerance (and the severity of the lactase enzyme deficit)
Why lactose intolerance is important
Undigested lactose enters the colon (large intestine) where it gets digested by bacteria, producing lactic acid and other acids. This can cause some unpleasant symptoms in many people.
Lactose intolerance can cause the following gastric symptoms:
- Abdominal cramps and pain
- Bloating
- Diarrhoea
- Flatulence
- Gas
- Nausea
The severity of the symptoms depends on a few factors:
- The level of lack of lactase enzyme in the digestive tract
- The amount of lactose ingested

