SEATTLE--A simple cocktail of vitamins and supplements can significantly slow the loss of brain function associated with aging in dogs, according to new research presented here 15 February at the annual AAAS meeting. The findings could have implications for delaying or preventing Alzheimer's disease in humans.
Aging dogs suffer from a loss of memory and learning ability similar to that seen in humans who go on to develop Alzheimer's disease. Canine brains also accumulate plaques made of b-amyloid, the destructive protein fragments believed to be associated with Alzheimer's in humans, making dogs a useful model for studying the disease. Previously, neurobiologist Carl Cotman of the University of California, Irvine, and his colleagues tested the cognitive abilities of older beagles that had been given a combination of vitamins C and E, a few fruits and vegetables, and alphalipoic acid and acetylcarnitine, two compounds normally present in low levels in the body that reduce the production of free radicals thought to be involved in Alzheimer's disease. They found that the mixture boosted the learning and memory skills of the dogs relative to similarly aged dogs that hadn't taken the supplements.
To find out if the mixture had reduced the buildup of b-amyloid plaques, Cotman's team compared the brains of the beagles that had taken the supplements for several years to those that hadn't. They found that the dogs on the diet had developed around 40% fewer plaques. "We were blown away by the results," says Cotman. Studies with rodents have also found improved cognitive function with one or more of the supplements. But because rodents don't naturally produce the plaques, those studies used transgenic mice and rats. Because dogs' neurological and cognitive decay more closely mimics that of humans, Cotman says the beagle study provides new hope that humans could also benefit from the diet.
The work "is innovative and potentially very important," says John Breitner of the University of Washington, Seattle, who studies the incidence of Alzheimer's in aging human populations. A treatment that delays onset of the disease could be a huge boon to public health and save millions of dollars a year, he and others say.