Mental Gymnastics: couch potatoes and Alzheimer's disease

by Barry Bittman, MD

If your favorite exercise is channel surfing cable TV, it's time to get off the couch!

What you're about to learn may be more important than you'd ever imagine.

New research has provided key insights that may help prevent a devastating disease that destroys quality of life. Dr. Robert P. Friedland and colleagues of Case Western Reserve University School of Medicine recently reported a 2.5 times increased risk for developing Alzheimer's disease in the couch potato set.

His study, published in the March 2001 Proceedings of the National Academy of Sciences, revealed that adults who routinely exercise their brains are less likely to develop Alzheimer's disease. The researchers conducted surveys on 70 year-olds—193 Alzheimer's patients and 358 control subjects who did not have the disease. Friedland's team analyzed leisure time activities performed during early and middle adulthood (ages 20-60). These included:

-         Passive activities including watching television, talking on the phone or listening to music.

-         Intellectual activities including reading, jigsaw or crossword puzzles, playing musical instruments, chess or other board games, knitting or woodwork.

-         Physical activities such as baseball, football or other sports such as bike riding, swimming, walking or skating.

According to Friedland, "The Alzheimer's patients were less active in all these activities except for television watching."

These results are not surprising considering that many researchers are now convinced education and intellectually demanding professions diminish the risk of Alzheimer's disease. Yet even when educational level and professional status were factored into this analysis, the conclusions stood on their own.

In another fascinating study performed in the prior year at University College, London University, scientists compared brain scans from 16 male London cabbies with 50 men from the general population. Among the cabbies, an area of the brain termed the "posterior hippocampus" was significantly larger.

This finding is especially important as only one fifth of the 3500 applicants for London cab licenses actually passed a test that requires (on average) two years of study. The difficult challenge is learning the layout of the city.

One might assume that men who passed had larger "memory" areas initially and that on-the-job experience had little effect. This, however, was not the case. The largest memory areas were found in drivers with the most time on the job. Experienced London cabbies pride themselves on working without maps, learning the streets and committing them to memory over the years.

While both studies show that mental stimulation has benefits that hold up to the rigors of science, one cannot conclude that Alzheimer's disease can be entirely prevented with a lifetime of intellectual workouts. This latest data, however, conservatively suggests delayed onset of dementia in people who remain mentally stimulated through leisure time activities.

Although both research investigations do not set forth to prove the underlying mechanisms responsible for these results, the ongoing process of building brain circuits through mental exercise seems like a feasible explanation. Another factor worthy of consideration is the stress reducing potential of leisure time mentally challenging and engaging activities.

Bruce McEwen, PhD, of Rockefeller University in New York proposed that repeated stress can lead to the body's inability to turn off its major biological stress pathway; a factor that can directly lead to significant memory loss. His breakthrough findings were reported in a review article published in the New England Journal of Medicine on January 15th, 1998. He focused on glucocorticoids (the body's natural steroids), and excitatory amino acid neurotransmitters (chemical substances that enable nerve transmission in key areas). McEwen noted that stress increases the levels of these two substances which directly result in atrophy or wasting away of nerve fibers in a key memory area of the brain called the hippocampus.

So if you're concerned with the fact that you can't remember to turn off the set, why not consider hiding the remote and seeking mentally challenging activities that can help you stay sharp. In the process you just might discover something that can have a major impact on the quality of your life—Mind Over Matter!

copyright 1998,1999, 2000, 2001 Barry Bittman, MD all rights reserved
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