WASHINGTON (Reuters) - Regular exercise can slow the development of Alzheimer's disease by changing the way brain-damaging proteins take up residence in the brain, researchers said Wednesday.
Their study of mice helps explain a growing body of evidence that keeping busy, physically and mentally, and eating certain foods can delay or even prevent the brain-destroying illness.
Paul Adlard and colleagues at the University of California, Irvine tested genetically engineered mice that begin at the age of three months to develop the clogs of amyloid protein, called plaques, that characterize Alzheimer's.
Half the mice were put into cages with running wheels.
Writing in the Journal of Neuroscience, the researchers said the animals allowed to exercise learned to navigate a water maze faster than mice kept cooped up without a wheel.
When they killed the mice and looked at their brains, the scientists found the animals that exercised had significantly fewer plaques and fewer bits of beta-amyloid peptides that are also associated with Alzheimer's.
"These results suggest that exercise -- a simple behavioral strategy -- in these mice may bring about a change in the way that amyloid precursor protein is metabolized," said Stephen Snyder, an Alzheimer's expert at the National Institute on Aging, which helped pay for the study.
Other research has found a variety of physical activities, such as dancing and walking, can prevent Alzheimer's; that eating omega-3 fatty acids found in soy, fish and other oils may protect against the disease; and that some drugs can slow its progression.
There is no cure for Alzheimer's, which causes dementia and affects an estimated 4.5 million Americans.