If you’re over 60, you probably know the experience: You open the cupboard door and abruptly forget what you opened it for. You start to introduce someone you’ve known for years and suddenly can’t remember the name. So-called senior moments are a common complaint of aging, but researchers haven’t understood what causes them. Now they may have an important lead. Neurologists at Columbia University Medical Center have identified a part of the brain, called the dentate gyrus, where age-related memory decline appears to be centered. Their latest findings, reported in the Annals of Neurology, show that declining activity in this brain region is closely correlated with rising levels of blood sugar.

Over the years, researchers have speculated about many reasons why age-related memory loss might occur. “This new study suggests that we may now know one of them,” explains Scott A. Small, MD, associate professor of neurology at the Sergievsky Center and the Taub Institute of Research on Alzheimer’s Disease and the Aging Brain at Cornell, who led the research.

The new findings make sense. Researchers have long known that elevated blood sugar levels damage blood vessels, nerve cells, and other tissues.Sustained high levels of blood sugar are the principle cause of the damage seen with diabetes.

By pinpointing a possible cause, the new research also offers several ways age-related forgetfulness might be delayed or prevented entirely. “Our findings suggest that maintaining blood sugar levels, even in the absence of diabetes, could help maintain aspects of cognitive health,” explains Dr. Small. There are three ways to do that. First, getting more physical activity, which helps drive blood sugar into working cells, where it is used for energy. Second, following a diet that avoids refined starches and sugars, which can send blood sugar levels soaring. Finally, for people who already have elevated blood sugar, or hyperglycemia, several drugs are available to bring the levels down into the normal range.

With the incidence of elevated blood sugar levels and the risk of diabetes reaching epidemic proportions, the Cornell findings offer one more reason to get your glucose levels checked as part of a regular physical exam. And, of course, to exercise more and eat fewer highly processed foods, advice that’s well worth remembering–so that you can go on remembering.