There's another advantage to being multilingual. Scientists say speaking a second language can rev up the brain in ways that seem to delay the onset of Alzheimer's disease.

The new research focused mostly on people with long-term bilingual ability. However, scientists said even people who learn a new language later in life, may see benefits.

Researchers emphasized that while being bilingual does nothing to prevent the onset of Alzheimer's, once the disease begins, those years of exercising robust executive control through the multilingual skills, provides a buffer, so that symptoms do not become apparent as quickly.

The study included 450 Alzheimer's patients, all of whom showed the same degree of impairment, during the time they were diagnosed. Half were bilingual; the rest were monolingual.