You've likely heard the advice many times before: If want to reduce your chances of getting Alzheimer's disease, you need to keep your brain active with tasks such as reading, writing and playing mentally challenging games. It's the old "use it or lose it" refrain.
But except for anecdotal evidence, there has been very little physical proof that this strategy works – until now.
A new study has revealed that people who engaged in cognitively stimulating activities throughout their lives had fewer brain deposits of beta-amyloid, a destructive protein linked to Alzheimer's disease.
The results are based on 65 healthy seniors. They were asked a series of questions to determine how frequently they "exercised" their brains – from age 6 to the present.
The participants also underwent high-tech brain scans to measure amyloid deposits.
"The more cognitive engagement they had, the less of this amyloid there was in their brain," said William Jagust, the study's principal investigator at the University of California, Berkeley.
Although all the participants were considered to be mentally fit when they were enrolled in the study, the researchers suspect that those with the highest levels of amyloid will go on to develop Alzheimer's as they grow older.
Dr. Jagust noted that it has been difficult to study the disease, partly because a diagnosis could not be confirmed until the patient died and the brain was examined in an autopsy. But recent advances in medical imaging make it possible to detect amyloid in the brains of living patients.
Amyloid plaques, which deposit between nerve cells, are thought to accumulate over a lifetime, eventually leading to interference in memory and other mental processes.
There is no known cure for Alzheimer's, and scientists still don't have a complete understanding of what causes the disease. Earlier research has suggested that certain genes and the aging process likely contribute to plaque formation.
The new study, published this week in Archives of Neurology, now indicates that a lifestyle factor – namely, mental stimulation – can affect the amount of these deposits. "This is the first time cognitive activity level has been related to amyloid buildup in the brain," said Susan Landau, a member of the research team at the university.
And that's good news because it suggests you can do something to reduce your chances of getting this dreaded disease, Dr. Landau added.
But starting to play Sudoku when you are already old and grey may be too late.
"Our findings suggest that it is a life-long pattern [of mental activity]that's important," Dr. Landau added.