Lactose is a sugar that is naturally found in foods containing milk (dairy products), which includes milk from cows, goats, and sheep. Dairy products comprise milk, butter, cheese, cream, yoghurt, and ice cream but, many other processed foods can also contain lactose, including cereals, baked foods (bread, crackers, cakes, biscuits, and pastry), sauces, and protein shakes.
Lactose intolerance is a condition in which digestive symptoms are present (such as bloating, diarrhoea, and gas), after the consumption of foods or drinks that contain lactose. These digestive symptoms are caused by lactose malabsorption: a condition in which the small intestine cannot digest, or break down, all the ingested lactose. Not everyone with lactose malabsorption has digestive symptoms after they consume lactose, only people who have symptoms are lactose intolerant. And some people with lactose intolerance can consume some amount of lactose without having symptoms, depending on individual tolerance.
It’s important to note that lactose intolerance is different from a milk allergy, which is an immune system disorder.1,2
How common is lactose malabsorption?
While most infants can digest lactose, many people begin to develop lactose malabsorption after this period. It is estimated that about 68 % of the world’s population has lactose malabsorption, being more common in Africa and Asia. In some regions, such as northern Europe, many people carry a gene that allows them to digest lactose after infancy, and lactose malabsorption is less common. In Europe, it is estimated that about 28% (19–37) of people have lactose malabsorption.3
Treatment for lactose intolerance
For most people with lactose intolerance, the symptoms can be prevented by reducing the amount of food that contains lactose, or by avoiding these foods completely. Taking a lactase supplement before having food or drink containing lactose may prevent some symptoms.
It is worth noting that fermented dairy products, such as yogurt, often pose fewer digestive challenges due to the presence of probiotic bacteria that assist in lactose digestion. Additionally, advancements in food technology have led to the development of lactose-free alternatives, providing options for individuals with lactose intolerance, since dairy products are rich sources of essential nutrients, including calcium, vitamin D, and protein, which play vital roles in bone health.
References:
- “Lactose Intolerance”. NIDDK. 2018.
- “Lactose Intolerance”. NHS inform. 2023
