Is Everyone Lactose Intolerant?

Only 35% of the global population can digest lactose in adulthood. Does this mean we are all really lactose intolerant? Lactose is a sugar found in milk and dairy products. When you are a child, the sugar is broken down by an enzyme called lactase in the small intestine. All humans are born with lots of lactase, but as we get older, these enzyme levels naturally decline. Historically, lactose intolerance is the baseline for adult humans. As ancient humans typically lost the ability to digest milk after weaning, however, when humans domesticated animals, we started to consume more dairy, which coincided with genetic mutations that allowed us to drink milk into adulthood. Today, most humans experience lactase malabsorption, meaning they don't fully break down lactose, and it may only cause mild issues. Lactose intolerance is reserved to describe people who experience Severe digestive symptoms or can only consume dairy in small doses.