Subjects: R and D
Diabetes and strokes precipitate age-related cognitive decline by impacting the hippocampus, a part of the brain involved in memory formation.
But the 2 conditions affect different parts of the hippocampus and do so via different mechanisms, according to a study in Annals of Neurology.
Scott Small and colleagues at Columbia University Medical Center used magnetic resonance imaging to document strokes and create functional maps of the hippocampus in 240 community-based elderly individuals including 60 with diabetes and 74 with brain infarcts.
They found that diabetes impacted hippocampal function via swings in blood glucose levels, while strokes impacted a different subregion via transient reductions in blood flow.
In the case of diabetes, adverse effects on the brain were correlated with mild to moderate blood sugar excursions, a conclusion that may have implications for so-called “normal, age-related” cognitive decline, because glucose regulation starts to deteriorate by the fourth decade of life.
“If we conclude this is underlying normal age-related cognitive decline, then it affects all of us,” Small told the New York Times.
And since physical exercise improves glucose regulation, “We have a behavioral recommendation — physical exercise,” he added.
Bruce S. McEwen, a neuroendocrinologist at Rockefeller University was impressed. “When we think about diabetes, we think about heart disease and all the consequences for the rest of the body, but we usually don’t think about the brain,” he said.
“We need to think about their…cognitive skills, and whether they will be able to keep up with the demands of education and a fast-paced society.”
Earlier studies had demonstrated that physical activity reduces the risk and diabetes increases the risk of age-related cognitive decline.