Final answer:
Lactose intolerance is a widespread condition caused by a lack of the enzyme lactase, preventing proper digestion of lactose in dairy products. Solutions include lactose-free milk and lactase supplements. Galactosemia is a related but more severe genetic disorder.
Step-by-step explanation:
Lactose Intolerance and Genetic Factors
Lactose intolerance is a condition where individuals lack the enzyme lactase, necessary to digest lactose, the sugar found in milk. This intolerance can lead to symptoms such as diarrhea, bloating, and cramps when dairy products are consumed. While the ability to digest lactose traditionally benefits populations depending on dairy, like Europeans, most adult mammals, including some human populations, typically lose this ability with age. It is particularly common among Asian adults to develop lactase deficiency later in life.
A much rarer but severe condition, galactosemia, stems from the absence of the enzyme needed to convert galactose to glucose. Lactose, being made up of glucose and galactose, poses a significant health risk to individuals with galactosemia.
To manage lactose intolerance, alternatives such as lactose-free milk and lactase supplement tablets are available. Understanding the genetic basis of lactose intolerance is crucial in regions with high dairy consumption, such as parts of the United States with European heritage, where dairy products are greatly demanded.