Washington DC: A team of researchers has developed a `gene signature` that can be used to predict the onset of Alzheimer`s years in advance.
The study aimed to define a set of genes associated with `healthy ageing` in 65 year olds.
Such a molecular profile could be useful for distinguishing people at earlier risk of age-related diseases.
This could improve upon the use of chronological age and complement traditional indicators of disease, such as blood pressure.
Lead author James Timmons, from King`s College London, UK, said that the discovery provides the first robust molecular `signature` of biological age in humans and should be able to transform the way that `age` is used to make medical decisions.
He added that this includes identifying those more likely to be at risk of Alzheimer`s, as catching those at `early` risk is key to evaluating potential treatments.
The researchers demonstrated that patients diagnosed with Alzheimer`s Disease had an altered `healthy ageing` RNA signature in their blood, and therefore a lower healthy age gene score, suggesting significant association with the disease.
Timmons added that this is the first blood test of its kind that has shown that the same set of molecules are regulated in both the blood and the brain regions associated with dementia and it can help contribute to a dementia diagnosis.
He noted that this also provides strong evidence that dementia in humans could be called a type of `accelerated ageing` or `failure to activate the healthy ageing program.
`The authors say that their `healthy age gene score` could be integrated to help decide which middle-aged subjects could be offered entry into a preventative clinical trial many years before the clinical expression of Alzheimer`s.
The study is published in the open-access journal Genome Biology.