Scientists may have discovered the cause of those age-related memory lapses we often call "senior moments."  Results from a new study suggest that such lapses are linked, in part, to increases in blood sugar levels as we age.  

Columbia University researchers (also click here) compared high-resolution brain images of humans and animals. They focused on a part of the hippocampus, a region of the brain linked to learning and memory loss.  

Scott Small, associate professor of neurology at Columbia and lead author of the study, says the correlation observed in humans was tested against real-time experiments with mice whose blood sugar levels were elevated systematically.

"Using the very same imaging technology, we can track these mice over time, over a course of a few months, and find that elevations of blood glucose do target this part of the hippocampus," he says.

Small says the areas of the hippocampus across species look very similar in terms of their basic functional properties and genetic profile.

"That's why mouse models in particular have turned out to be a good and tractable model to understand many diseases," he says.

With the knowledge that glucose levels normally increase over a lifetime, the study suggests that even in the absence of a disease, controlling blood sugar levels can help avert the cognitive decline normally associated with aging.  Small says exercise can play a key role because it can improve the body's ability to regulate glucose, according to previous studies.

"It's reasonable to consider that physical exercise might be a behavioral way to try to ameliorate, in part, age-related memory decline," he says.  

Small says while more study is needed to address the complex interactions of age-related disease and the hippocampus, the research finds that options like exercise, diet or targeted drugs could help preserve cognitive health among the elderly.  

The research was published in the December issue of Annals of Neurology.