Raised blood sugar may lead to memory problems even in people with no signs of diabetes, a study has found.
Participants with lower blood sugar levels were likely to have better scores in memory tests.
In one test, which involved recalling a list of 15 words 30 minutes after hearing them, higher blood sugar correlated with poorer memory.
"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," lead researcher Dr Agnes Floel, from the Charite University Medicine in Berlin, Germany, said.
"Strategies such as lowering calorie intake and increasing physical activity should be tested."
The research appeared in the latest online edition of the journal 'Neurology'.
Dr Clare Walton, from the Alzheimer's Society, said: "We already know that Type 2 diabetes is a risk factor for developing Alzheimer's disease but this new study suggests that higher blood sugar levels may also be linked to poor memory in people without diabetes.
"The research suggests that regulating blood sugar levels might be a way to improve people's memory, even if they don't have diabetes.