Lactose Intolerance: Causes, Symptoms, and Global Impact

Lactose intolerance is a common digestive condition where the body is unable to properly digest lactose, the sugar found in milk and dairy products. This condition arises from a deficiency of lactase, the enzyme responsible for breaking down lactose into glucose and galactose in the small intestine. Without sufficient lactase, undigested lactose passes into the colon, where it is fermented by bacteria, leading to symptoms like bloating, diarrhea, and gas.

Lactose intolerance varies in severity among individuals. Symptoms can range from mild discomfort to severe digestive distress, depending on the amount of lactose consumed and the level of lactase activity. It is important to differentiate lactose intolerance from a milk allergy, which involves an immune response to milk proteins and can be more serious.

The prevalence of lactose intolerance varies globally. It is more common in certain populations, particularly those of East Asian, African, and Native American descent, where it can affect up to 90% of adults. In contrast, it is less common in populations with a long history of dairy consumption, such as those of Northern European descent.

Management of lactose intolerance typically involves dietary modifications, such as reducing or eliminating lactose-containing foods, using lactose-free dairy products, or taking lactase enzyme supplements. Many individuals with lactose intolerance can tolerate small amounts of lactose and may benefit from consuming lactose-reduced dairy products or fermented dairy products, which have lower lactose content.
Lactose Intolerance: Causes, Symptoms, and Global Impact