Biological age differs substantially for everyone. Aging clocks like Horvath’s epigenetic clock have been based on the pattern of methylations until now. These patterns are small chemical groups that attach to DNA and change with age.
Earlier the transcriptome was considered too complex to indicate age as sometimes genes transcribe a large amount of mRNA and sometimes less. So it was impossible to develop precise aging clocks based on gene activity.
However, Meyer and Schumacher eliminate the differences in gene activity using a mathematical trick.
The BiT clock categorizes genes into two groups (on or off), thereby decreasing high variation and making aging predictable from the transcriptome.
Meyer comments, “Surprisingly, this simple procedure allows very accurate prediction of biological age, close to the theoretical limit of accuracy. Most importantly, this aging clock also works at high ages, which were previously difficult to measure because the variation in gene activity is particularly high then.”
BiT is based on around 1,000 different transcriptomes of C. elegans, with precisely known lifetimes. Model organisms like the nematode give a controllable view of the aging process, which allows discoveries of biomarkers as well as the effects of external influences (like UV radiation or nutrition on longevity).
The clock gives room to accurately predict the pro-and anti-aging impacts of gene variants and various external factors. In addition, it also showed that immune response genes and neuron signaling are essential for the aging process.
Schumacher explained that BiT age could also predict human age quickly and accurately. “Measuring biological age is important to determine the influence of environment, diet, or therapies on the aging process and the development of age-related diseases. This clock could therefore find wide application in aging research. Since BiT age is based purely on gene activity, it can be applied to any organism,” he adds.