Researchers at King's College London in the UK have designed a simple blood test that can identify people who get old very quickly and are at high risk of age-related brain diseases. Even years before symptoms manifest, this blood test can predict people who are likely to suffer Alzheimer's, dementia, or other forms of mental disabilities later in life.
The novel diagnostic test analysed over 50,000 gene markers from three tissue types of 65-year-old subjects. These tissues include human muscle, brain and skin. Researchers generated a set of molecular profiles from the said age group after two decades of re-testing the subjects at five-year intervals. Successfully, the study team was able to narrow down the set of gene determinants into 150 useful markers that indicate 'healthy ageing'.
James A. Timmons of the University of Exeter Medical School was the lead researcher of the multi-tissue RNA analysis. In his statement, he explained that everyone has been using birth year or 'chronological age' to assess how old a person is. However, most of us accept that people in the same age group are not the same. There has been no accurate test for biological age up until now that they have conducted this research.
With the RNA profile, the team defined what they called 'healthy age gene score' and used this parameter to compare different individuals. They demonstrated that if a person gets a higher score, he or she is younger and has a better health state.
Seven hundred 70-year-old human subjects volunteered to undergo health data analysis over two decades. Although the subjects were born within the same year, their RNA profiles displayed a wide distribution by up to four times within the limits of 'healthy age gene score'. Those that had greater gene scores indicated high association to the two critical determinants of healthy living - better mental state and renal function. On the other hand, patients diagnosed with Alzheimer's disease were found to have modified RNA signatures and were poor in 'healthy age gene score'.
As Timmons highlighted, this blood test can indicate how fast a person gets old on the basis of biological age and not on the length of time that he or she has lived. Physical capacity may be deceitful at the moment when symptoms have not yet appeared. Hence, these molecular signatures of human biological age are helpful to give a hand signal to those people who are likely to suffer age-related diseases later in life, the Daily Mail writes.
With this study, there is still a need to explain why some people age faster than others. We may not have the insights as to how we can improve our gene scores or prevent ourselves from accelerated ageing. But at least, people should have understood by now how to use the word 'age' rightly especially in terms of making medical decisions.
The study appears in the journal Genome Biology.