Rejuvenation: The Science of Reversing Biological Age

Several interventions have recently emerged to reverse rather than just attenuate aging.

There’s a lot of talk these days about stopping or slowing down aging. But what about rejuvenation — the reversal of aging? Can we actually turn back the clock to become biologically younger?

Anti-aging vs. Rejuvenation

First things first: what constitutes rejuvenation, and how does it differ from anti-aging?

The line between rejuvenation therapies and other longevity interventions, such as those that slow down or prevent aging, is hazy, and these strategies are frequently used interchangeably. Anti-aging indicates the maintenance or preservation of aging biomarker status. This is typically measured by biomarkers of aging, such as clocks based on DNA modification patterns or the length of telomeres — the protective DNA caps of chromosomes.

Rejuvenation goes one step further and requires a strong, prolonged, and systemic reduction in biological age. A more important feature common to the existing and potential rejuvenation interventions is the exceptional enhancement of regenerative capacity.

The reversal of aging is inherently multidimensional: it may include a reduction in damage at the molecular level, renewed cell functionality at the cellular level, and meaningful physiological improvement at the organismal level. Some age reversal therapies may also induce lifespan extension. Along these lines, the effect at one level of biological organization is usually accompanied by connected effects at other levels.