Abnormal Blood Sugar Levels and Mental Decline in Seniors

‘Not too little, not too much, but just right’, goes the truism. And in the case of blood sugar levels in older folk, this seems to be more important than we thought. Two recently published studies point this out.

In the first, posted in the journal Neuron, Northwestern University researchers found that a key brain protein is changed when the brain has a deficient supply of energy, i.e. sugar. The altered protein, called elF2alpha, is indirectly responsible for the production of sticky protein clumps of amyloid – the plaques that are distinctive of Alzheimer’s. Improving blood flow to the brain (e.g. through exercise, lowering cholesterol, and lowering blood pressure) would therefore be a preventive step to this dread disease. Treadmill desks at work, for instance, are claimed to have to improved mental functioning.

The second study, reported in the Annals of Neurology, builds on the concept that ‘senior moments’ (we all have them) occur in elders who are ‘hippocampically challenged’. The hippocampus is the part of the brain that shows signs of damage in early Alzheimer’s disease, and a part of the hippocampus called the dentate gyrus seems to be involved particularly in the normal age-related decline of memory.

Magnetic resonance imaging (MRI) was used to study brains of 240 non-demented elders, who had an average age of 80. Sixty of them had type 2 diabetes and 74 had small areas of cell death on MRI. Changes on MRI in the dentate gyrus were found only in those subjects with a raised glucose level, not with changes in body mass index (BMI), cholesterol levels, or insulin levels. These findings suggest that raised glucose levels are contributory to age-related memory defects. Again, exercise can counteract this problem, to a certain degree. One of the principal investigators, Dr S. Small, says: “I now recommend physical exercise to my aging patients as a way to preserve cognitive ability”. Again, exercise seems to be the key.