Why human lifespan is rapidly increasing: solving "longevity riddle" with "revealed-slow-aging" hypothesis

Abstract

Healthy life span is rapidly increasing and human aging seems to be postponed. As recently exclaimed in Nature, these findings are so perplexing that they can be dubbed the 'longevity riddle'. To explain current increase in longevity, I discuss that certain genetic variants such as hyper-active mTOR (mTarget of Rapamycin) may increase survival early in life at the expense of accelerated aging. In other words, robustness and fast aging may be associated and slow-aging individuals died prematurely in the past. Therefore, until recently, mostly fast-aging individuals managed to survive into old age. The progress of civilization (especially 60 years ago) allowed slow-aging individuals to survive until old age, emerging as healthy centenarians now. I discuss why slow aging is manifested as postponed (healthy) aging, why the rate of deterioration is independent from aging and also entertain hypothetical use of rapamycin in different eras as well as the future of human longevity.

Figure 1.. Fast and slow aging.

In slow aging, the onset of deterioration is postponed but the rate of deterioration is not changed.

Figure 2.. Preferential survival fast- versus slow-aging individuals.

(A) In the past, slow-aging individuals (open circles) died prematurely and fast-aging individuals (closed circles) survived into old age. (B) Now, slow-aging individuals (open circles) survived into old age as healthy (biologically young) and outlive faster aging individuals (closed circles).

Figure 3.. Traditional medicine increases survival (extends deterioration phase) without affecting the onset of deterioration.

Figure 4.. Anti-aging drugs will delay the onset of deterioration without affecting deterioration.