The New York Times
We looked at the medical records of 400 Alzheimer’s patients. On average, the bilinguals showed Alzheimer’s symptoms five or six years later than those who spoke only one language. This didn’t mean that the bilinguals didn’t have Alzheimer’s. It meant that as the disease took root in their brains, they were able to continue functioning at a higher level. They could cope with the disease for longer.
Source
http://www.nytimes.com/2011/05/31/science/31conversation.html?_r=1&src=tptw
