London - Alzheimer’s and diabetes may be the same disease, scientists claim.
They have uncovered evidence that the debilitating form of dementia may be late stages of type 2 diabetes.
The discovery would explain why nearly three quarters of patients with this form of diabetes go on to develop Alzheimer’s.
Researchers from Albany University, New York State, believe the excess insulin they produce gets into the brain and disrupts key chemicals.
Around 2.5 million Britons suffer type 2 diabetes, which is triggered by obesity, and the numbers have almost doubled since the 1990s.
Around 70 percent of them go on to develop Alzheimer’s compared with just 10 percent of healthy men and 20 percent of healthy women.
Although doctors have known for some time that type 2 diabetes sufferers are far more at risk, there has been little research into the link.
Professor Ewan McNay, a British researcher based at Albany University, said: “The discovery could explain why people who develop type 2 diabetes often show sharp declines in cognitive function.
“People who develop diabetes have to realise this is about more than controlling their weight or diet. It’s also the first step on the road to cognitive decline. At first they won’t be able to keep up with their kids playing games, but in 30 years’ time they may not even recognise them.”
Professor McNay fed rats on a high-fat diet to bring on type 2 diabetes and carried out memory tests, which found that the animals’ concentration deteriorated rapidly as the disease progressed.
When he later examined their brains he found clumps of amyloid protein had formed – the same found in those of Alzheimer’s patients.
The researcher, who presented his findings at the Society for Neuroscience conference in San Diego, California, said: “High levels of insulin swamp this enzyme so that it stops breaking down amyloid.
“The latter then accumulates until it forms toxic clumps that poison brain cells. It’s the same amyloid build-up to blame in both diseases. Type 2 diabetics really do have low-level Alzheimer’s.” - Daily Mail