October 24, 2013
Higher Blood Sugar Levels Linked To Impaired Memory
redOrbit Staff & Wire Reports - Your Universe Online
Individuals who have blood sugar at the lower end of the normal range perform better on memory tests than non-diabetics with higher glucose levels, according to new research published online Wednesday in the peer-reviewed medical journal Neurology.
Lead author Agnes Flöel of Charite University Medicine in Berlin and her colleagues recruited 141 individuals with an average age of 63, according to Nanci Hellmich of USA Today. None of those men and women had type 2 diabetes or prediabetes, and none of them had demonstrated any signs of cognitive or memory-related impairments.
“The study participants took a series of memory tests and had their blood sugar tested. They also had brain scans to measure the size of the hippocampus area, which plays an important role in memory,” Hellmich said. “The findings showed that chronically higher blood glucose levels exert a negative influence on memory.”
Specifically, the subjects were asked to review a list of 15 words, and then recall them 30 minutes later, according to Los Angeles Times reporter Mary MacVean. The ability to recall fewer words was associated with higher blood sugar levels, she said, and those individuals also were found to have less volume in the hippocampus – a region of the brain associated with both short- and long-term memory.
“Flöel says the findings suggest that even for people within the normal range of blood sugar, lowering their levels might be a possible way to prevent memory problems as they age,” Hellmich said. “She points out that the study is relatively small and doesn't prove cause and effect. There's a need for large clinical trials to test whether lowering glucose will help with the prevention of dementia.”
“Earlier research has shown ‘deleterious effects of diabetic glucose levels on brain structure, particularly the hippocampus,’ the researchers wrote,” according to MacVean. She added that they also explained that “impaired glucose tolerance and Type 2 diabetes also have been associated with lower cognitive function and a higher incidence of dementia, including Alzheimer's disease.”
Robert Ratner, the chief scientific and medical officer with the American Diabetes Association, told USA Today that the results of the study only show an association between glucose levels and memory, not necessarily a causal relationship.
He explained that they have not shown that memory loss is caused by higher glucose levels, or that reducing blood sugar would improve recall. Even so, Ratner noted that it was “not surprising that glucose levels can potentially have these kinds of negative impacts. The risk of dementia is higher in people with diabetes. It has been well established that elevated glucose impacts brain function and recovery in people following a stroke.”