Blood sugar linked to loss of memory
The Associated Press
WASHINGTON — Losing your memory in old age may have nothing to do with Alzheimer's and lots to do with blood sugar.
So suggests new research that found that people who don't process blood sugar normally — a silent, pre-diabetic condition — are likely to suffer poor memory and even a shrinkage of the brain region crucial for recall.
The good news: If the small study from New York University were confirmed, simple diet and exercise could help many people protect their brains from the fogged memory associated with aging.
Maybe the threat of memory loss — an oft-cited fear among aging baby boomers — will provide the final push for people to take those steps, says lead researcher Dr. Antonio Convit.
"That's a great motivator to stay off the calories and stay off the couch," he said.
For every Alzheimer's patient, there are eight older people who suffer enough memory loss to significantly harm their quality of life yet have no dementia-causing disease, says Convit, an NYU psychiatry professor who set out to uncover the causes.
Blood sugar was a natural suspect; scientists have long known that diabetics are at higher-than-normal risk for memory problems, possibly because diabetes harms blood vessels that supply the brain and other organs.
The new study, published yesterday in the Proceedings of the National Academy of Sciences, found that people's memory may be harmed long before they develop full-fledged diabetes — and that it's a problem of fuel, not plumbing.
Convit studied 30 nondiabetic middle-aged and elderly people. He measured how they performed on several memory tests; how quickly they metabolized blood sugar after a meal; and, using MRI scans, the size of the hippocampus, the brain region responsible for recent memory.
The slower those outwardly healthy people metabolized blood sugar, the worse their memory was — and the smaller their hippocampus was, Convit found.
Unlike most other tissues that have multiple fuel sources, the brain depends on blood sugar for almost all its energy, Convit explained. The longer glucose stays in the bloodstream instead of being metabolized into body tissues, the less fuel the brain has to store memories.
Convit's study sheds important light on yet another risk of high blood sugar, said Dr. Fran Kaufman, president of the American Diabetes Association. But she cautioned that it was a small study that requires confirmation before doctors test glucose solely for memory complaints.
But if confirmed, the same advice for lowering people's overall diabetes risk — drop a few pounds and do exercise as simple as walking 30 minutes a day — apparently would help to protect people's brains, too, Kaufman said.