Tag: Congenital lactase deficiency

Affecting an estimated 1 in 60,000 newborns in Finland, congenital lactase deficiency is an extremely rare genetic condition that means a baby cannot digest the lactose in breast milk or formula. This raises a critical question: can humans be lactose intolerant to human milk? The answer is yes, but only under these specific, very uncommon circumstances, distinguishing it from the more common adult-onset form.

While roughly 65% of the world's population is lactose intolerant, the reasons behind this common trait in Finnish individuals are particularly interesting. A mix of inherited factors, including a higher incidence of the severe congenital form and the more common adult-type, explains why Finnish people are lactose intolerant at a notable rate compared to some other Northern European nations.