Arguing a Limit on Life Span
Despite a long, slow trend upwards in life expectancy (at birth, as an adult, and for old people) there are still those researchers who believe that there are limits on human life span. This is on the one hand silly: the scientific community will in time overcome the causes of aging. On the other hand it is most likely true that there exist one or more slow degenerative processes still largely unaffected by modern medicine that kill everyone who survives all of the common causes of age-related death.
Based on autopsy data from supercentenarians, a good candidate for a present lifespan-limiting process in humans is the development of senile amyloidosis: misfolded proteins aggregate to clog the heart and blood vessels. But we can easily envisage ways to treat this condition, such as by training the immune system to destroy the errant proteins, as is presently under development in the Alzheimer's research community.
Aging and age-related death are composed of a laundry list of items that can all be tackled successfully by the near future of medical research: it's just a matter of prioritizing and funding the necessary work, something that at present the public and broader research community has little enthusiasm for, sadly.
The past 200 years have enabled remarkable increases in human lifespans through improvements in the living environment that have nearly eliminated infections as a cause of death through improved hygiene, public health, medicine, and nutrition. We argue that the limit to lifespan may be approaching. Since 1997, no one has exceeded Jeanne Calment's record of 122.5 years, despite an exponential increase of centenarians. Moreover, the background mortality may be approaching a lower limit.We calculate from Gompertz coefficients that further increases in longevity to approach a life expectancy of 100 years in 21st century cohorts would require 50% slower mortality rate accelerations, which would be a fundamental change in the rate of human aging. Looking into the 21st century, we see further challenges to health and longevity from the continued burning of fossil fuels that contribute to air pollution as well as global warming. Besides increased heat waves to which elderly are vulnerable, global warming is anticipated to increase ozone levels and facilitate the spread of pathogens. We anticipate continuing socioeconomic disparities in life expectancy
Pessimism abounds in this age of ours that is characterized by wealth, plenty, and rapid, accelerating progress in technology and medicine. There is nothing new about that, of course. People have long been entranced by the false vision of doom ahead.