Harman D
University of Nebraska College of Medicine, Omaha 68198-4635.
Proc Natl Acad Sci U S A. 1991 Jun 15;88(12):5360-3. doi: 10.1073/pnas.88.12.5360.
Aging is the accumulation of changes responsible for the sequential alterations that accompany advancing age and the associated progressive increases in the chance of disease and death. Average life expectancies at birth in the developed countries are now approaching plateau values as the aging changes associated with the environment and disease near irreducible levels. The inborn aging process is now the major risk factor for disease and death after around age 28 in the developed countries and limits average life expectancy at birth to approximately 85 years. Future significant increases in average life expectancy--a rough measure of the healthy, productive life-span, i.e., the functional life-span--in these countries will be achieved only by slowing the rate of production of aging changes by the aging process. Many theories have been advanced to account for the aging process. The free radical theory of aging is discussed briefly. The importance attached to increasing the functional life-span dictates that aging hypotheses be explored for practical means of achieving this goal while work continues toward a consensus on the cause(s) of the aging process. Efforts to further increase the functional life-span by conventional measures are now almost futile, whereas those directed toward slowing the aging process are just beginning. These new efforts show promise.
衰老指的是一系列变化的积累，这些变化导致了随着年龄增长而出现的相继改变，以及与之相关的疾病和死亡几率的逐渐增加。在发达国家，由于与环境和疾病相关的衰老变化接近不可降低的水平，出生时的平均预期寿命目前正接近平稳值。在发达国家，大约28岁之后，内在的衰老过程成为疾病和死亡的主要风险因素，并将出生时的平均预期寿命限制在约85岁。在这些国家，未来平均预期寿命（衡量健康、有生产能力的寿命，即功能寿命的一个粗略指标）的显著提高，只有通过减缓衰老过程产生衰老变化的速度才能实现。人们已经提出了许多理论来解释衰老过程。本文简要讨论了衰老的自由基理论。鉴于延长功能寿命的重要性，在继续就衰老过程的原因达成共识的同时，需要探索衰老假说，以找到实现这一目标的切实可行方法。通过传统措施进一步延长功能寿命的努力现在几乎是徒劳的，而旨在减缓衰老过程的努力才刚刚开始。这些新的努力显示出了希望。
