What is lactose intolerance?
Lactose intolerance is a common digestive problem. If you are lactose intolerant you lack the lactase enzyme in the small intestine, which is needed to break down milk sugar molecules. This means that the intestine cannot assimilate milk sugar, i.e. lactose. If you have stomach problems – gas, diarrhoea, bloating, pains or similar symptoms – it may be due to lactose intolerance. Lactose is found primarily in dairy products, but also as an additive in other products, e.g. certain chips and powdered products.
There are three different forms of lactase deficiency:
Adult lactase deficiency, which is the most common form. Some people have a reduced capacity to form the enzyme lactase as early as about age three. The capacity to form lactase cannot be regained, but a certain capacity may remain, which means that small quantities of lactose can still be broken down.
Secondary lactase deficiency appears in connection with some other injury to the intestine. With untreated gluten hypersensitivity, inflammation in the intestine, severe stomach flu or after an abdominal operation, the intestinal membrane may be damaged in such a way that it cannot produce lactase. When the injury is healed, most often the capacity to produce lactase returns.
Congenital lactase deficiency is extremely uncommon and is often discovered when the child is nursing or receives a substitute for mother's milk.
How can I tell if I am lactose intolerant?
If lactose cannot be broken down in the small intestine, the lactose will be fermented by bacteria in the large intestine and give rise to gas. The gas formation and the water-absorbent effect of the lactose produces symptoms such as diarrhoea, bloating, stomach gurgling and colic pains. The symptoms may vary from person to person. Some people tolerate dairy products in small quantities and others not at all.
What should I do if I am lactose intolerant?
If you are lactose intolerant you should avoid or limit the intake of products that contain lactose. This is a simple way for you to be rid of your complaints. The enzyme lactase may also be added to the diet. If you want more help or advice you can contact a physician or a dietician.
If you want to know how much lactose a certain food product contains, there is a list on the Swedish National Food Administration website.