Researchers have said that maintaining normal blood sugar levels as we age may be more important than we previously imagined as it may help prevent age related memory loss.

Researchers in the December issue of Annals of Neurology have said that the increase in blood sugar levels is a normal part of aging and using high-resolution brain imaging showed that rising blood sugar levels selectively affects a part of the hippocampus, a part of the brain critical to learning and memory.

Senior study author Dr. Scott Small, an associate professor of neurology at the Taub Institute for Research on Alzheimer's Disease and the Aging Brain at Columbia University Medical Center in New York City said, "We have known that exercise improves blood sugar and that it helps prevent age-related memory loss. In this study, we were able to show the specific area of the brain that is impacted by rising blood sugar. This would suggest that anything to improve regulation of blood glucose would potentially be a way to ameliorate age-related memory decline."

In the study the researchers used MRI to record the functioning of the hippocampus in 240 healthy older people of an average age of 80. Sixty of them had diabetes while
74 had brain "infarcts" -- some damage to brain tissue. The MRI's showed that the diabetes and the infarcts had different mechanisms working in each disorder as they were linked to separate parts of the hippocampus.

"We had previously shown that physical exercise strengthens a part of the brain involved with aging but, at the time, we didn't know why physical exercise would have this selective benefit," Small said. "Now we have a proposed mechanism. We think it's because subjects who exercised had better glucose handling."

Linda Nichol, PhD, of the National Institute on Aging said the research may help explain why diabetic people are at increased risk of developing Alzheimer's disease."We already know that physical exercise can help people stay cognitively sharp as they age," she adds. "This study may help explain why."

Mark Mapstone, an associate professor of neurology at the University of Rochester Medical Center in New York, said: "If these findings are replicated and confirmed, I think the implications could be very important, specifically, that maintaining optimal blood sugar levels throughout aging is a feasible way to [slow or prevent] cognitive decline. It goes beyond diabetes to look at people who don't have diabetes. The implication is even if you don't have a clinical condition of diabetes, that you can still do something about cognitive aging."

"Beyond the obvious conclusion that preventing late-life disease would benefit the aging hippocampus, our findings suggest that maintaining blood sugar levels, even in the absence of diabetes, could help maintain aspects of cognitive health," Small says in a news release.

The study was funded by the National Institute on Aging, the American Diabetes Association, and the McKnight Brain Research Foundation.