Blood sugar in the “high normal” range – short of levels associated with diabetes or even pre-diabetes – can lead to brain shrinkage, according to results of a new study from Australia. Using multiple brain scans, researchers at the Australian National University in Canberra found evidence of the shrinkage in seniors between the ages of 60 and 64 whose blood sugar was high but not high enough for a diagnosis of diabetes or pre-diabetes.
The scans were taken four years apart, and the researchers considered smoking, alcohol consumption, age and high blood pressure, all factors that may contribute to a change in brain volume. Even after adjusting for these variables, they noted a decrease in brain volume of six to 10 percent in those participants whose blood sugar was “high normal.”
The researchers suggested that if further studies confirm their findings, both the definition of diabetes and blood glucose levels considered harmful may need to be re-evaluated. Shrinkage of the brain’s hippocampus and amygdale normally occur with age and with dementia.