A genetic test to assess how well or badly your body is ageing to predict when you are likely to die, reports a team at King's College London in the journal
Saying that "biological age" is a more useful predictor of health than how old you are, the test can help identify those at high-risk of dementia and other age-related disorders.
The test compares the behaviour of 150 genes to identify an ageing signature in cells. A healthy ageing signature is common to all tissues and can help predict longevity and brain-function decline.
The test was developed by comparing 54,000 markers of gene activity in healthy, but largely sedentary, 25 and 65-year-olds and then zeroing down to 150 key genes.
The study found that while poor lifestyle choices are bad for health, they did not appear to affect the speed at which your body ages. Researchers say the final diagnosis of your future health risks has to be done by combining biological age and how you live your life.
The test can help in disease prevention. For example, people who are ageing rapidly need to be screened for cancer, dementia, neuro-generative diseases and heart disease.