Middle-aged people with type 2 diabetes are four times more likely to be diagnosed with dementia than those without the condition, researchers have said.

Previously, academics have reported that type 2 diabetes can trigger the development of harmful proteins in the brain, which can increase cause dementia.

During the study, the team of scientists examined the brain health of more than 4,000 adults for 10 years to assess whether signs of dementia were present.

They discovered that the adults aged between 55 and 64 with type 2 diabetes were 40.3% more likely to develop dementia than those without the condition.

In addition, they found that individuals aged 65 and over are most at risk of developing dementia if they have heart disease.

Meanwhile, adults aged 70 and over are most at risk of being diagnosed with the memory loss condition if they have previously suffered a stroke.

Top author Professor Emer McGrath said: “This shows that people who have diabetes in their fifties are more likely to develop dementia – probably because having the condition at a younger age can do more damage to your body and brain.

“It matters because these people have four times the risk of dementia in the decade after most people enter retirement.”

Professor McGrath added: “No one wants to be diagnosed with a condition like Alzheimer’s disease when they are retired, have stopped working, and want to start enjoying their life without worries.”

Head of Research at Alzheimer’s Research UK, Dr Rosa Sancho said: “The findings from this study confirm existing research, which links vascular risk factors, such as high blood pressure and diabetes, with an increased risk of developing dementia in later life.

“We know that poorer vascular health can increase the chances of developing small vessel disease and other conditions that affect blood flow in the brain, which then damages our brain cells irreparably.”

She concluded: “Studies like this are good for highlighting links, but we need to understand more about why and how these conditions affect dementia risk.

“With this knowledge, researchers can then design treatments and prevention strategies to benefit people in their midlife – a critical timepoint for reducing your risk of dementia.”

The study has been published in the journal Neurology.

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