Researchers in Germany recruited 141 people, average age 63, who did not have type 2 diabetes or prediabetes, and who showed no signs of memory problems. The study participants then 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.
Researcher Agnes Flöel of Charité University Medicine in Berlin says she and her colleagues "correlated long-term blood-sugar levels with the number of words people could recall on a memory test." They found that higher long-term blood-sugar levels went along with being able to recall fewer words.
"We also found that people with higher blood-sugar levels had smaller volumes in the size of their hippocampus," she said. She said that the published 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.
Robert Ratner, chief scientific and medical officer for the American Diabetes Association, told USA Today it's important to realize that this study shows an "association. They are looking at a single glucose level in time and memory. They haven't shown that the memory loss is either due to the higher glucose level, or that lowering glucose would improve memory."
Flöel's research shows that people with type 2 diabetes who have poor blood-sugar control are at a greater risk of dementia. "Elderly people with type 2 diabetes are almost twice as likely to develop dementia."
So how hard is it to lower your blood sugar if you are in the normal range? According to Ratner, your glucose level is determined by a combination of "genetics, diet and hormonal response." "For those who have perfectly normal glucose metabolism, there is little they can do to change their level. The body controls glucose very tightly. The body is that good."
If you want to keep your blood sugar in a healthy range, that doesn't mean "you should never eat sugar," he says. It means you should eat a healthy diet with a reasonable number of calories and a balanced intake of protein, fat and carbohydrates, he says.
And physical activity is important, because it improves the body's ability to utilize insulin, so a regular exercise program makes a person more insulin-sensitive -- their body responds to the insulin they make more effectively, he says.
Neurology, Oct 2013