Posted on 7 December 2020
Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.
Why is this research important: Your chronological age is the number of years you’ve been alive. Your biological age is how old your body seems, based on your risk for diseases such as heart disease, diabetes, obesity, and cancer. Biological, or epigenetic, clocks are biochemical tests which can predict biological age. Biological aging is The clock is based on DNA methylation levels. DNA methylation is the process in which methyl groups attach to regions of the DNA called CpG sites where they act as genetic switches, turning specific genes on or off. The increasing inaccuracy of these methyl groups to attach to the correct CpG sites as we get older is thought to be one of the root causes of aging. By mapping which CpG sites are being unduly methylated as we age we can build up a predictive model that can be used to assess the biological age, giving rise to the epigenetic clock.
Improving the accuracy of these clocks will allow for greater ability to accurately measure an individual’s true biological age.
What did the researchers do: Using samples from 490 individual from the Irish longitudinal study on ageing, scientists examined and compared the association of four different epigenetic clocks – Hannum, Horvath, PhenoAge and GrimAge – with a range of different metrics for age-related decline. These included walking speed, grip strength, frailty, cognitive ability, mental state, attention reaction time, reaction time, mortality, and polypharmacy (the concurrent use of multiple medications).
Key takeaway(s) from this research: They found that the Horvath and Hannum clock were not predictive of health. PhenoAge was associated with 4/9 of the outcomes, but only when the individuals social and lifestyle factors were not accounted for. Whereas, the GrimAge epigenetic clock was associated with 8/9 of the outcomes and was still associated with frailty, mortality and polypharmacy when taking into account social and lifestyle factors. These findings demonstrate that the GrimAge clock is currently the forerunner in the race to successfully predict age-related decline.