What is commonly referred to as milk sugar?

Lactose is commonly referred to as milk sugar because it is the sugar primarily found in milk and dairy products. This disaccharide consists of two monosaccharides: glucose and galactose. When consumed, lactose is broken down in the small intestine by the enzyme lactase into its constituent sugars, which can then be absorbed into the bloodstream.

Lactose plays a crucial role in the nutrition of young mammals, providing energy and having a mild flavor that encourages the consumption of milk. Its presence in milk is significant for those who are lactose intolerant, leading to difficulties in digesting dairy due to insufficient lactase production.

In contrast to lactose, glucose is a monosaccharide and is the primary energy carbohydrate for cells in the body; fructose is another monosaccharide found in fruits; and sucrose, which is table sugar, is a disaccharide made of glucose and fructose. These sugars have distinct properties and sources, but it is lactose specifically that is celebrated as the sugar present in milk.