A study of older people in the UK suggests people with diabetes lose cognitive ability faster than people with normal blood sugar control.
The findings, published today in Diabetologia, was led by researchers at Imperial College London. They studied more than 5,000 people over the age of 50 and measured their cognitive decline over a 10 year period.
What’s cognitive decline?
Cognitive decline describes changes in our mental abilities, such as memory, concentration or decision making skills. These usually get worse with age, but cognitive decline describes changes beyond what you’d expect to see with normal aging, although it shouldn’t affect day-to-day functioning.
People who experience cognitive decline may be more likely to get dementia one day, but it doesn’t always lead to dementia. Whilst previous research has shown a link between diabetes and dementia – particularly in Type 2 diabetes – in this study the team were only looking at cognitive decline.
Diabetes linked to poor performance
The researchers measured cognitive decline by testing the memory and language skills of the participants. They repeated these tests every two years and monitored changes over time.
They included people with and without diabetes in the study, but didn’t find out which type of diabetes people had. They found that everyone performed worse on these tests as they aged. But in people with diabetes, this worsening (or cognitive decline) was quicker than in people who had normal blood glucose control. They also found that, whether people had diabetes or not, higher blood glucose levels were linked to poorer performance on the cognitive tests.
More research needed
Whilst this research highlights a potential link between blood glucose control and our brain’s health, it doesn’t show that diabetes is the direct cause of these changes in the brain. We don’t yet know why diabetes and cognitive decline could be linked, or if tight blood glucose management could prevent or delay these changes.
Ultimately, understanding more about how diabetes affects the brain will be important to tease apart the risks and causes, and work out which condition comes first.
Dr Emily Burns, Head of Research Communications at Diabetes UK, said: “This study adds to growing evidence linking diabetes and high blood glucose levels to a quicker progression of cognitive decline, which can increase risk of developing dementia in the future. 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.
“There are ways you can lower your risk of developing Type 2 diabetes and cognitive impairments, including dementia. These include maintaining a healthy weight, enjoying a healthy balanced diet, limiting alcohol intake, avoiding smoking, exercising regularly and keeping your blood pressure in check.”