Men and women who are fluent in more than one language may be protected in part from the memory ravages of Alzheimer’s disease, a new study suggests. The findings add to a growing body of evidence that intellectual challenges like learning languages, playing musical instruments, reading or doing crossword puzzles may help keep the brain sharper for longer.
The study, from researchers at the Rotman Research Institute and York University in Toronto, Canada, reviewed the medical records of 211 people who were diagnosed with likely Alzheimer’s disease. About half spoke one language, while the others spoke two or more. They found that being bilingual delayed the onset of Alzheimer’s symptoms for as long as five years. The findings were published in the medical journal Neurology.
"We are not claiming that bilingualism in any way prevents Alzheimer's or other dementias,” said the study leader Dr. Fergus Craik, “but it may contribute to cognitive reserve in the brain, which appears to delay the onset of Alzheimer's symptoms for quite some time." The "cognitive reserve" theory holds that educational pursuits like learning languages build up connections between nerve cells in the brain. When a disease like Alzheimer’s strikes and destroys parts of the brain, enough healthy cells and pathways remain intact to keep memory and thinking working longer.
The brains of people who speak two languages still show deterioration from Alzheimer's effects on the brain. Bilingual people with Alzheimer’s, though, seem to have extra brain capacity that allows them to fend off symptoms like memory loss, confusion, and difficulties with problem solving and planning.
The researchers found that on average, bilingual patients were diagnosed with Alzheimer's 4.3 years later than those who spoke only one language. Symptoms tended to crop up five years later in the multilingual group.
The study adds to mounting scientific evidence that suggests lifestyle factors can have an impact on Alzheimer’s onset. In addition to mental activity, regular exercise and a heart-healthy diet have been suggested as possible ways to help keep the mind and memory sharp into old age.
"Although a great deal of research is being focused on the development of new and more effective medications for Alzheimer's disease, there are currently no drug treatments that show any effects on delaying Alzheimer's symptoms, let alone delaying the onset of these symptoms by up to five years," said Dr. Morris Freedman, another study leader.
Source: Craik FIM, Bialystok E, Freedman M.; Delaying the onset of Alzheimer disease: bilingualism as a form of cognitive reserve. Neurology. 2010;75:1726-1729.