Have you ever thought that you used to drink milk easily as a child, but as you grow up, the same milk becomes a threat to your stomach? Has your body really given up milk, or is it just a biological trick? Scientists say it contains DNA and a specific enzyme, lactose, that changes with age. Now, let us know why and how this happens.
You may have often noticed that doctors have always advised adults who experience stomach problems, such as bloating, to avoid drinking milk or milk tea. Have you ever wondered why? Let’s find out.
About 75% of the world’s adult population has difficulty drinking large amounts of milk, whereas most people drank milk easily in childhood. Why does this happen? The answer is lactose intolerance.
In fact, almost everyone has the ability to drink milk in childhood because the body produces a special enzyme, lactose. This enzyme breaks down the sugar in milk, called lactose, into usable energy. That is why babies can easily get nutrition from milk.
But over time, this ability begins to decline in most people. Some people lose it at the age of 3, some after the age of 20 and some for much longer, while some never lose it.
People in whom this lactose gene is activated in childhood can drink milk as infants, but this ability gradually declines with age. People who can still drink milk as adults have a specific DNA mutation.
Scientists have named this mutation lactose persistence. This means that their bodies continue to produce lactose, making lactose easier to digest. Scientists say this is a natural evolutionary process.
People who consumed more dairy products had a higher incidence of this gene mutation, while those who did not drink milk were more likely to be unable to digest milk as adults.