The exact identities of the diagnostic molecules were still secret, but the researchers believed the finding was an important breakthrough that had the potential to help with diagnosis at the very earliest stages of the disease.
"Although there are other known markers of early Alzheimer's disease, such as an accumulation of the toxic protein beta amyloid in the brain, testing for these involves expensive or invasive procedures that can't be used in routine clinical practice," Williams said in a statement.

A blood test to diagnose Alzheimer's would be quick and easy to administer, relatively inexpensive, and readily available.

"We know that the levels of these microRNA differ in people who have Alzheimer's and people who don't. So if a GP took a blood sample from a patient who was beginning to show symptoms of memory loss, what we'd do is analyze that blood and see how that patient's pattern of microRNA compares against established patterns."

The team was also working on a blood test to predict whether a person without symptoms was likely to get Alzheimer's in the future.