Even non-diabetics could suffer memory problems associated with high blood sugar.

Researchers looked at 141 patients around the age of 63 who had never been diagnosed with diabetes or pre-diabetes. None of the participants were overweight, drank more than three-and-a-half drinks per day, or had memory impairment, an American Academy of Neurology news release reported.

The participants underwent memory and blood-glucose (sugar) level tests. The study subjects were also given brain scans to determine the size of their hippocampus, which "plays an important role in memory."

The team found the participants who had lower blood sugar levels were more likely to score highly on the memory test than those with higher blood glucose levels.

The memory test asked participants to remember a list of 15 words 30 minutes after hearing them, the people with higher blood sugar levels recalled fewer words.

Those who had a seven mmol/mol increase in "long-term marker of glucose control called HbA1c," were not able to recall as many of the words.

The people who had higher glucose levels also tended to have smaller hippocampus volumes.

"These results suggest that even for people within the normal range of blood sugar, lowering their blood sugar levels could be a promising strategy for preventing memory problems and cognitive decline as they age," study author Agnes Flöel, MD, of Charité University Medicine in Berlin, Germany, said. "Strategies such as lowering calorie intake and increasing physical activity should be tested."