High levels of sugar in the blood may be linked with poor memory that comes as we age, a new study suggests.

The small study on non-diabetics ranging in age from 53 to 89 found those with high blood sugar (glucose) tended to have a smaller hippocampus, a key region of the brain for recent memory.

If the findings are confirmed, it could mean aging baby boomers could protect their brains by losing weight and exercising, which help keep blood sugar levels under control.




Our bodies need glucose as a fuel source. But in diabetics, the sugar can't enter their tissues, and they end up with too much glucose in the blood.

Scientists knew diabetes harms blood vessels supplying the brain, heart and other organs. Diabetics are known to be at higher risk for memory problems.

For every Alzheimer's patient, there are eight older people with memory loss severe enough to harm their quality of life, said Dr. Antonio Convit, a professor of psychiatry at New York University.




Convit's study aimed to find out why.

He and his colleagues looked at 30 middle-aged and elderly men and women.

The researchers:

  • measured how well they performed on several memory tests
  • evaluated how quickly they metabolized blood sugar after eating
  • used MRI scans to measure the size of the hippocampus

They found the slower people metabolized blood sugar, the worse their memory was, and the smaller their hippocampus was.

People can appear to be healthy but have "impaired glucose tolerance," a pre-diabetic condition where glucose metabolism slows.

"We have demonstrated that impaired glucose regulation is associated with memory dysfunction and shrinkage of the hippocampus," Convit said in a release.

"Our study suggests that this impairment may contribute to the memory deficits that occur as people age, and it raises the intriguing possibility that improving glucose tolerance could reverse some age-associated problems in cognition."

The small study needs to be confirmed, cautioned Dr. Fran Kaufman, president of the American Diabetes Association.

If so, dropping a few pounds and exercising may help protect people's brains, she said.

The study appears in Monday's online issue of the Proceedings of the National Academy of Sciences.