Exercising your brain reduces your risk of developing Alzheimer's Disease. "Use it or lose it" is not just a popular notion according to the results of a research study from the Rush Alzheimer's Disease Center and Rush - Presbyterian - St. Luke's Medical Center in Chicago.

How was the study conducted?

The authors followed 800 older (65 and over) but dementia-free Catholic nuns, priests, and brothers for around 5 years. The participants were asked about the sorts of activities they engaged in that involved information processing and "exercising" their brains. The authors graded and labelled these cognitive activities. They then assessed the amount of time spent engaging in cognitive activities, developing a points score in which five points were gained for an activity being done every day, down to 1 point for once a year or so.

The participants also gave a thorough medical history and were screened for depression. Then all the participants were put through a range of cognitive ability tests. These were done yearly over the period of the study.

What were the results?

A total of 111 of the participants developed Alzheimer's Disease during the course of the study. The others all showed some degree of cognitive decline as would be expected in an aging population.

The authors found that frequently exercising the brain with cognitive activities slowed the rate of cognitive decline. The participants who reported the most frequent participation in cognitive activities at the outset of the study had 47% less chance of developing of Alzheimer's Disease at the end of the study than those doing the least amount of cognitive activity.

The study found that "exercising" the brain had the most marked positive effects on the preservation of working memory, perceptual speed and global cognition.

What factors appeared to influence risk?

Factors that were linked to lower risk of Alzheimer's Disease included:

• viewing television and listening to radio, etc.
  
  
•  reading newspapers, books, etc.
  
  
• playing games such as cards, checkers crosswords or other puzzles.
  
  
• going to museums.
  

What did the authors conclude?

The authors proposed some theories to explain their findings:

• Repetition of certain cognitive skills makes older people more efficient in these skills and less vulnerable to the disease process.
  
  
• Frequent cognitive activity may strengthen processing skills such as working memory and perceptual speed, which may help to compensate for age-related decline.
  

It should be considered that pre-existing cognitive decline (not enough to be diagnosed as Alzheimer's Disease at the outset of the study) could have precluded cognitive activities rather than cognitive activities preventing cognitive decline. The authors doubted this was the case but raised it as a possibility.

"These results suggest that frequent participation in cognitively stimulating activities is associated with reduced risk of AD" the authors conclude.

Robert S. Wilson  et al. Participation in Cognitively Stimulating Activities and Risk of Incident Alzheimer Disease.JAMA, Feb 2002; 287: 742 - 748.