Finch C E, Pike M C
Neurogerontology Division, Andrus Gerontology Center, University of Southern California, Los Angeles, USA.
J Gerontol A Biol Sci Med Sci. 1996 May;51(3):B183-94. doi: 10.1093/gerona/51a.3.b183.
This study examined maximum life span predictions obtained with the Gompertz mortality rate model, which assumes that there is a constant rate of acceleration in the age-related mortality of adult populations. The influence of population size N on the maximum life span (tmax) was shown to be small, because the numeric impact of N is reduced to ln[ln(N)]. In contrast, the Gompertz exponential mortality coefficient alpha has much more influence on the tmax, which varies as 1/alpha. Examination of select mammals and birds showed that tmax as reported for local populations agrees very well with that calculated from mortality rate coefficients for these local populations. However, the tmax as reported from the world literature, which is designated here as the "world record, " shows major discrepancies for some species from the predicted tmax based on the local population. We demonstrate that these discrepancies are not due to population size, but represent other factors that may include genotype, diet, and environmental dangers. Potential increases in human tmax will depend mostly on slowing the age-related acceleration of mortality. If the degree of mortality rate slowing achieved in rats by diet restriction is applied to humans, then the median human life expectancy would approach the present tmax of 120 years.
本研究考察了用冈珀茨死亡率模型得出的最大寿命预测，该模型假定成年人口的年龄相关死亡率存在恒定的加速率。研究表明，种群大小N对最大寿命（tmax）的影响较小，因为N的数值影响会降至ln[ln(N)]。相比之下，冈珀茨指数死亡率系数α对tmax的影响要大得多，tmax随1/α变化。对选定的哺乳动物和鸟类的研究表明，当地种群报告的tmax与根据这些当地种群的死亡率系数计算得出的结果非常吻合。然而，世界文献中报告的tmax（此处称为“世界纪录”）显示，某些物种的tmax与基于当地种群预测的tmax存在重大差异。我们证明，这些差异并非由于种群大小，而是代表了其他因素，可能包括基因型、饮食和环境危险。人类tmax的潜在增加将主要取决于减缓与年龄相关的死亡率加速。如果将通过饮食限制在大鼠中实现的死亡率减缓程度应用于人类，那么人类的预期寿命中位数将接近目前120岁的tmax。
