Lactose intolerance is not a disorder.
It is actually more common in the world than lactose tolerance.
Originally, people in the world were all lactose intolerant. Their bodies ceased the production of the enzyme lactase after an early age.
Their diets did not contain much milk anyways, so it was not a problem.
Somewhere in Europe, a mutation occured where lactase continued to be produced through adulthood.
Lactose tolerance is a dominant allele, so the trait became very common in Western Europe.
Person 1: Wow, You're lactose intolerant? Is that some kind of freak mutation?
Person 2: Actually, you have the mutation, sir.
Prices shown in USD.
Type your email address below to get our free Urban Word of the Day every morning!
Emails are sent from firstname.lastname@example.org. We'll never spam you.