Casein intolerance vs lactose intolerance
Because both are found in cow’s milk, casein and lactose intolerance often get confused and conflated. In fact, the two conditions are different.
A casein intolerance is the body’s inflammatory reaction to the casein protein, and its difficulty in breaking it down. If somebody is lactose intolerant, they don’t have enough of the enzyme lactase in their system, and can’t digest lactose (a naturally occurring sugar).