US study links Alzheimer’s to brain protein levels

Rising levels of a naturally occurring protein in the brain could give up to a decade’s warning of Alzheimer’s disease, before memory problems have become apparent, according to new research.

In the US study, published by the American Academy of Neurology, blood samples were taken from 20 people who later developed Alzheimer’s. The samples were taken up to 10 years before diagnosis and were later tested.

Blood was taken once from 26 people with Alzheimer’s and from 16 with frontotemporal dementia. Samples were also taken from 46 healthy people. Scientists found the level of protein was significantly different in the healthy controls than in those with dementia, both before and after symptoms developed.

"This is important, as it suggests that altered blood proteins may be a marker of early Alzheimer's disease," said Prof Gordon Wilcock of Oxford University.

The number of patients examined is small, so larger trials will be needed, said Dr Tara Spires-Jones of the University of Edinburgh’s centre for cognitive and neural systems. “While this study is promising, caution should be taken to not interpret the results as a foolproof blood test for Alzheimer’s at this stage.”