Learn a New Language
The evidence: In an Annals of Neurology study published this year, bilingual elderly adults whose native language was English scored higher in reading-comprehension and intelligence tests than did their monolingual peers, even if they had had lower intelligence-test scores back when they were 11 years old. It didn’t matter whether they had learned the second language as kids or later in life; almost everyone in the bilingual group reaped the same cognitive gains. While it’s unclear why, research suggests that learning a new language might create new neuron-to-neuron pathways in the brain.
How to do it: No need to enroll in a pricey program. Learn free online (try livemocha.com), or download podcasts (such as those at radiolingua.com), then practice at a language-exchange meet-up. While some research suggests that intensive courses and fluency offer best results (perhaps by enhancing the size of certain brain areas), even a basic knowledge of a second language can keep you sharp. You can also hit the (foreign) books to expand your brain, literally.