What is lactose?
Lactose is a type of naturally occuring sugar found in milk and milk products. Lactose is the main carbohydrate in dairy products.
Lactose is a disaccharide, which means it is made up of two monosaccharides molecules – glucose and galactose.
Important lactose facts
- Lactose makes up about 30-50% of milk’s energy value
- Lactose is present in all dairy products
- Yoghurt and some cheeses have less lactose, making them easier to digest for those with lactose intolerance
- The lactose in sheep’s cheese and goat’s cheese are more tolerated by those with lactose intolerance as they contain very little lactose
Why lactose is important
If lactose remains undigested when foods rich in this sugar are eaten (milk and dairy products), then it is deemed that there is a lactose intolerance. Lactase is the enzyme that breaks down lactose into the monosaccharides (the simple sugars) of galactose and glucose so that lactose can be digested properly.

