High blood sugar levels linked to cognitive decline regardless of diabetes status

A link between high blood sugar levels over a long period of time and cognitive decline has been observed in a new study.
A team from Imperial College London studied more than 5,000 people aged over 50, with and without diabetes, who had their cognitive abilities measured over 10 years. Tests of memory and concentration were conducted every two years.
Everybody’s cognitive ability declined with age, but those with high blood sugar levels were more likely to fare worse on tests of memory and concentration. These findings persisted irrespective of whether participants had diabetes or not.
Similar results have been reported in numerous studies over the years, but there is no reason why having diabetes should necessarily lead to cognitive decline. Keeping good control of blood sugar levels through eating a healthy diet and getting regular exercise can help with brain health.
Researchers are still investigating links between diabetes and cognitive decline, and whether good long-term control of blood sugar levels could delay or even prevent brain changes.
While cognitive decline is symptomatic of an increased risk of dementia, this study did not examine dementia risks but focused on general cognitive decline.
Dr Emily Burns, Head of Research Communications at Diabetes UK, which funded the study, said: “We now need to understand if and how diabetes causes this decline, or if these conditions simply share the same biological processes. This will be crucial in finding ways to help people with diabetes keep their brain healthy.”
Benedict Jephcote, Editor of, said: “Recently we have seen great advances being made by thousands of members of the public who have demonstrated that diabetes need not be a progressive disease that gets worse over time.
“The Low Carb program has shown that people can achieve much lower sugar levels and reduced dependence on medication by following simple lifestyle changes. This provides significant optimism that other aspects of health, such as cognitive function, may also improve as a result. We are very keen to keep observing.”
The findings have been published in the Diabetologia journal.

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