7 September 2015
New research published in the journal Genome Biology reports on a genetic signature of ‘healthy ageing’ that could provide a good indication of future cognitive health risks.
The healthy ageing signature is based on 150 ‘markers of genetic activity’ (a transcriptomic or expressed RNA signature) identified from research in healthy (but sedentary) 25 and 65 year olds.
The RNA signature, which is said not to be affected by ‘lifestyle biomarkers’, produces a higher ‘score’ in healthy controls than people with any form of cognitive impairment. It can also function as a diagnostic for Alzheimer disease (AD). A higher score was also linked with better renal (kidney) function; both cognitive and renal decline are said to be ‘important determinants of all-cause mortality’ and indicative of general organ decline.
Lead researcher Prof Jamie Timmons of King's College London told the BBC: "There's a healthy ageing signature that's common to all our tissues, and it appears to be prognostic for a number of things including longevity and cognitive decline”, explaining that from the age of 40 onwards it could be used as a marker of how well an individual is ageing.
The researchers say that full clinical utility for the test would probably result from combination with additional data, but that using it alongside an assessment of lifestyle factors could provide a more accurate picture of health. It is suggested that the test might inform a change in approach to organ donation and cancer screening – criteria are currently dictated by chronological age, but it might be more effective to use a measure of ‘biological age’ such that older people with healthier ageing could still donate organs, and younger people with more rapid cellular ageing might need earlier cancer screening.
Another area for potential future exploration is the molecular mechanisms associated with healthy ageing, and regulation of the genes that contribute to the healthy ageing signature, as these could be targets for new interventions to improve or stimulate healthy ageing.