From Dr Mercola today.

People with an inability to quickly bring down high blood sugar levels--a pre-diabetic condition--are more likely to suffer from memory loss. This may help explain why memory loss occurs as we age.


For every Alzheimer's patient, there are eight elderly people who do not have dementia but whose quality of life is harmed by memory loss.

Blood sugar has been thought to play a role, as diabetics have a greater risk of memory problems, possibly because diabetes harms blood vessels that supply the brain and other organs.


The study of 30 non-diabetic middle-aged and elderly people raises the possibility that exercise and weight loss, which help control blood sugar levels, may be able to reverse some of the memory loss that is associated with aging.


Various factors were measured in the study including how participants performed on several memory tests, how quickly they metabolized blood sugar after a meal, and, through the use of MRI scans, the size of the hippocampus, the brain region responsible for learning and recent memory.


Results indicated that people who metabolized blood sugar slowly had a smaller hippocampus and scored worse on tests for recent memory.


The brain gets most of its energy from blood sugar, so if glucose stays in the bloodstream rather than being metabolized into body tissues, the brain has less fuel available to store memories.


The study is the first to show an association between the size of the hippocampus and the ability to control blood sugar levels in the body. Though further research is needed, this association suggests that delivery of glucose may influence hippocampal structure and function, researchers said.


Further, if confirmed the results indicate that controlling blood sugar levels through exercising and eating a healthy diet may help to protect the brain from memory loss associated with aging.


Science Blog

full item is here
http://www.mercola.com/2003/feb/15/sugar_memory.htm