The BBC recently reported on a presentation given by Jay Olshansky, professor of public health at the University of Illinois at Chicago. According to Olshansky,
The human body was not designed for long-term use. It was designed for short-term use and in effect what we’re doing is pushing these bodies beyond the end of the warranty period for living machines.
Olshansky notes that while Life Expectancy around the world are still increasing, the rate at which they are increasing is beginning to slow down. Specifically, Olshansky claimed that without significant advances from the biomedical sciences, life expectancy would not reach 100 in the United States until sometime in the 26th century.
When considering such pessimistic predictions, there is one important thing to keep in mind. Olshansky is simply the latest in a long line of public health officials who have said that it would take many centuries to reach certain levels of life expectancy; most of those experts were disproved within their lifetime.
In fact the amazing that about Olshansky’s figures is that he worries about how long it will take to reach a life expectancy of 100. The debate used to revolve around whether or not even developed nations would ever be able to reach life expectancies of 85. Considering that some sub-groups of the American population have achieved life expectancies in excess of 97, very few people today doubt that the 85 year mark will be reached.
The unstated problem underlying Olshansky’s number is that a life expectancy of 100 for a country like the United States would be achievable if people valued long life above anything else, but Americans tend to consider living a good, if moderately shortened life, to be preferable to living a less adventuresome and indulgent — though likely longer — life span. This is especially the case since living to be past 80 still subjects individuals to relatively high risks of diseases, such as Alzheimer’s, that diminish the value of living those extra years. Even given that, however, the United States leads the world in the number of people who are older than 80 years of age.
Olshansky and others underestimate the rate of discovery that biomedical sciences are about to unleash. Researchers have made astounding leaps in knowledge about diseases such as Alzheimer’s since the mid-1980s, and the pace of understanding is clearly accelerating very quickly (a good example of this is the incredibly quick response to AIDS. AIDS activists like to complain that the government and corporations are dragging their feet, but the incredible speed with which AIDS was identified and treatments created is unprecedented in the history of medical science. It took researchers almost 50 years just to decide how polio as transmitted).
It would be very surprising if the life expectancy of the developed nations didn’t reach 100 before the end of this century, and the developing world should begin to catch up too assuming they can work out the interminable problems with war and political illiberalism.
A bigger problem will be how a potential rise in life expectancy could throw off current projections of a stabilization of world population around 2050 AD or so.
Life expectancy of 100 ‘unrealistic’. Jonathan Amos, BBC, February 19, 2001.