Protecting your brain from Alzheimer's

Main Category: Public Health
Article Date: 11 Aug 2003 - 0:00 PDT

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Brain images show that people who are more intelligent and better educated use their brains differently, which in turn may help explain why keeping the mind active protects against Alzheimer's disease, researchers reported this week.

Study after study has shown that people who do puzzles, who dance and who keep their minds active have a lower risk of Alzheimer's -- the most common cause of dementia.

This has led scientists to believe that some people have a 'cognitive reserve' that allows them to tolerate more damage from Alzheimer's and other brain diseases.

But is it due to brain size, connections, or something else?

Yaakov Stern, a professor of neuropsychology at Columbia University in New York and colleagues have done a series of brain imaging experiments that suggest it's not how much brain you have, but how you use it, that matters.

Writing in the August issue of the Journal of Clinical and Experimental Neuropsychology, Stern and colleagues said they tested 19 people with a range of IQs from below to above average.

'In this particular study we looked at normal people and we gave them a memory task to do -- they had to recognize these shapes, sort of nonsense squiggly shapes,' Stern said in a telephone interview.

'We looked to see if we could see differences in brain activity in people as a function of IQ.'

They did.

Functional magnetic resonance imaging, which can see cell activity as it happens, showed more activity in the frontal lobes in people with higher intelligence.

'One area where there seemed to be more activity in higher IQs was the right medial frontal gyrus,' Stern said. He does not know if that area of the brain is significant.

'What is important to us at this point is not the areas themselves, although I am sure they are meaningful, but to establish this differential activity.'

The next step, Stern said, will be to compare young people with old people, and healthy old people against Alzheimer's patients. Already his studies show that young and old people do use their brains in different ways.

Stern's team has also shown that education tends to protect against Alzheimer's. Whatever is at work must start early in life, he said -- before the brain damage caused by Alzheimer's starts.

Currently more than 4 million Americans have Alzheimer's, which is always fatal and for which there is no cure.

Those numbers are expected to jump as the population ages.

The disease is marked by protein 'plaques' and tangles of nerve fibers that kill off surrounding neurons. Symptoms start with simple memory loss and steadily worsen, leaving patients unable to care for themselves.