Lactose Intolerance
/ˈlækt.oʊs ɪnˈtɒl.ər.əns/noun
A condition in which the body is unable to properly digest lactose, a sugar found in milk and dairy products.
Did you know?Lactose intolerance is believed to have evolved as humans transitioned from a nomadic lifestyle to agriculture, leading to a decreased need for dairy products in adulthood.
Etymological Timeline
Proto-Indo-European
PIE
*lakt-
“to milk, the act of drawing milk from mammals.”
Latin
Latin
lactis
“milk, the fluid produced by mammals.”
Old French
Old French
lactose
“sugar in milk, derived from the Latin root.”
19th Century
English
lactose
“a sugar present in milk, coined from Latin origins.”
20th Century
English
intolerance
“inability to digest or tolerate, from Latin 'intolerantia', meaning 'unendurable'.”
Modern English
English
lactose intolerance
“the combination of the inability to digest lactose, a modern medical term.”
Explore more surprising origins