Aging clocks have been developed to measure the biological age of humans more accurately than the traditional chronological age based on the date of birth. Environmental factors, such as smoking or diet, can influence biological age, causing it to deviate from chronological age. Scientists David Meyer and Professor Dr. Björn Schumacher from the University of Cologne have discovered that aging clocks actually measure the increase in stochastic changes in cells. Their study, published in Nature Aging, suggests that the aging process follows a programmed pattern.
As individuals age, the control over processes that occur in their cells becomes less effective, leading to an increase in stochastic results. This can be seen in the accumulation of stochastic changes in DNA methylation, which refers to the chemical changes that affect DNA. These changes are strictly regulated within the body, but random changes can occur over time, leading to an accumulation of variation that is a highly accurate indicator of a person’s age.
In addition to DNA methylation, the increase in stochastic variations in gene activity can also be used as an aging clock. The scientists suggest that any process in the cell that exhibits stochastic variations could potentially predict age. It is important to determine if these aging clocks can show the effectiveness of interventions that slow down the aging process or identify harmful factors that accelerate aging.
Using available datasets, the scientists have shown that smoking increases random changes in humans, while interventions such as lower calorie intake in mice can reduce the variation in methylation patterns. They have also demonstrated that stochastic noise can be reversed by reprogramming body cells into stem cells. By comparing human fibroblasts from the skin that were reprogrammed into stem cells, the scientists were able to show a reversal of high variation indicative of old age to low stochastic noise similar to that of young stem cells.
Meyer and Schumacher hope that their research on the loss of regulation and accumulating stochastic variations will lead to new interventions that target the root cause of aging and potentially lead to cellular rejuvenation. One possible target for these interventions could be repairing stochastic changes in DNA or improving control of gene expression. The findings of this study could pave the way for new treatments to combat the aging process and improve overall health and longevity.
