Active Minds May Keep Alzheimer's at Bay
January 23, 2007
By Amanda Gardner
HealthDay Reporter
TUESDAY, Jan. 23 (HealthDay News)
For the first time, scientists have shown that learning slows the build-up in the brain of protein plaques and tangles that are the signature of Alzheimer's disease.
Although the study was conducted in mice, it does reinforce the idea that, in humans, maintaining an active mind may help delay or even prevent Alzheimer's disease.
"This has shown for the first time that using your brain can protect you physically," said Kim Green, co-lead author of the study and a postdoctoral researcher at the University of California, Irvine. "We show that when you do this, it causes changes in the brain, and these changes are protective."
"It's an interesting study, and part of what it does is advance the notion that mental exercise has a protective effect against Alzheimer's," said Dr. Gary Kennedy, director of geriatric psychiatry at Montefiore Medical Center in New York City.
According to the Alzheimer's Association, about 4.5 million Americans have the brain-robbing disorder, a number that has more than doubled since 1980. Many more suffer from cognitive impairment, which could be a harbinger of Alzheimer's.
Many experts believe that Alzheimer's is caused by a steady accumulation of amyloid plaque proteins in the brain.
Previous studies had shown that "mental exercise" could delay the onset of the disease, but the proof came only in the form of memory and other cognitive testing measures.
The authors of this study, which is published in the Jan. 24 issue of the Journal of Neuroscience, wanted to see if there was a biological correlation for those encouraging results.
The study involved hundreds of "transgenic" mice -- mice that had been genetically altered to develop human Alzheimer's disease.
Mice in a "learning" group were allowed to swim in a tank of water until they discovered a submerged platform on which to stand. This training took place four times a day for one week at two, six, nine, 12, 15 and 18 months of age. The other group of mice swam in the tank just once before their learning and memory skills were tested and their brains examined.
Mice up to 1 year old in the learning group developed 60 percent less of the proteins that form plaques and tangles compared to mice in the non-learning group, the researchers found.
"The sort of learning we gave the animals was fairly mild, yet it still had a big effect," Green said.
However, by 15 months of age, the learning mice had declined and were now physically and cognitively identical to the non-learning mice.
