There are many benefits to bilingual immersion education. Immersion education is much more than just learning to speak a foreign language. The immersion process allows students to actually learn content in a foreign language. Learning the language is part of the process, but learning content helps the brain use the language to actually develop the ability to speak and comprehend.
Research has shown that students who speak more than one language have improved executive functions of the brain, along with an increase in cognitive development thus improving overall academic achievement.
Current article on the benefit of bilingual education: