Aubrey de Grey: Repairing Some Age-Related Damage May Be Enough to Achieve Longevity Escape Velocity
Aubrey de Grey: Repairing Some Age-Related Damage May Be Enough to Achieve Longevity Escape Velocity
On July 12, Aubrey de Grey responded to a clip from Matt Kaeberlein's June interview. Their disagreement concerns three distinct goals: restoring a specific function, buying time, and fully reversing age-related changes.
In an interview published on June 25, Kaeberlein said that many aspects of biological aging can be reversed, but that he considers the complete reversal of all age-related changes almost unattainable. His argument concerns the scale of the task. Cells and tissues accumulate many different forms of damage with age, while the body changes across a vast number of parameters at once. Returning every parameter to its previous state is much harder than improving a single function.
Kaeberlein nevertheless considers longevity escape velocity a reasonable goal. The term describes a situation in which medical progress adds more than one year to a person's expected lifespan for every year that passes. He supports this goal but doubts that current evidence gives us reason to expect it within the next 10–15 years.
In his response to the clip, de Grey wrote:
“The questions are simply what proportion of age-related damage can be repaired today, what proportion is likely to become repairable in the foreseeable future, what proportion must be repaired to achieve longevity escape velocity, and what proportion must be repaired to reverse biological aging completely,” de Grey wrote.
A therapy may restore the function of a single organ. To achieve longevity escape velocity, new repair methods would need to compensate for aging throughout the body. Complete reversal of biological aging would require the removal of accumulated damage from every tissue. Without a precise definition of the goal, the word “reversibility” conflates these different tasks.
In a subsequent clarification, de Grey agreed with Kaeberlein that some types of age-related damage in mammals may prove harder to repair than others, and that the time required to develop such repairs remains unknown. He believes that longevity escape velocity can be achieved without repairing these forms of damage.
Kaeberlein supports this goal but sees no basis for expecting the field to approach it within the next 10–15 years. Researchers have not yet learned how to reliably slow biological aging or extend lifespan even in laboratory animals. De Grey expects that achieving longevity escape velocity will not require complete repair of the body.