Feed the mind and save the brain, study shows

WASHINGTON - People who are more intelligent and better educated use their brains differently, which in turn may help to explain why keeping the mind active can protect against Alzheimer's Disease, researchers say.

United States studies have 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 is not how much brain you have, but how you use it, that matters.

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

"We looked at normal people and we gave them a memory task to do - they had to recognise these shapes, sort of nonsense squiggly shapes," Professor Stern said.

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

They did.

Scans of cell activity showed more activity in the right medial frontal gyrus in people with higher intelligence.

He did not know if that area of the brain was significant.

But having established differential activity the next step would be to compare young people with old people, and healthy old people against Alzheimer's patients, Professor Stern said.

Already his studies show that young and old people use their brains in different ways.

The team has also shown that education protects against Alzheimer's.

Whatever was at work must start early in life, he said - before the brain damage caused by Alzheimer's started.

An estimated 38,000 New Zealanders have dementia, and it is estimated that 8 per cent of adults over the age of 65 are affected.

- REUTERS