According to CNN, learning a new language can rewire your brain and help stave off Alzheimer’s disease later in life. Ellen Bialystok, from York University in Toronto, Canada, found that bilinguals are diagnosed with Alzheimer's disease four to five years later than their monolingual counterparts.
When it comes to the beneficial effects bilingualism has on the brain, education levels do not matter. In fact, the most profound effects were found in people who were illiterate and had no education. Bilingualism was their only real source of mental stimulation, and as they got older, it provided protection for their aging brains.
More experience with bilingualism leads to greater cognitive changes. The earlier you start being bilingual, and the more intense your bilingual experience is on a daily basis, the more changes happen in your brain.
People who are highly educated, or people who have very demanding jobs, might have similar benefits with later onset of Alzheimer's disease. Bilingualism is just one way to create "cognitive reserve" for your brain. The important thing, Bialystok says, is keeping your brain active and engaged throughout your lifetime.