Tuesday, August 24, 2010

I’m Gonna Live Forever, Part 1

Every so often, I come across another person who, grounding his faith firmly in modern medicine, hopes to attain the ripe old age of 200. It’s always 200. And the person is generally male, religiously an atheist, and politically a libertarian.

The argument goes something like this: People used to live until 50. Now they live to 80. So, if the government doesn’t interfere with scientific advancement, I must be destined to reach 200.

This drives me absolutely crazy. Overall life expectancy in the United States (see Table 1) has been in the seventies since my father was two. This has led to speculation in social science circles that there is, in fact, an upper limit on life expectancy at birth. Others see the trend continuing to increase very slowly. Either way, that’s far cry from the layman predictions I’ve heard.

TABLE 1*


What’s not being appreciated is how much of that increase in the average lifespan should be credited to Louis Pasteur’s disciples rather than any current developments. Now that childhood is virtually non-life threatening (Baby Boom anyone?) and “dying in childbirth” is something that’s discussed among genealogists, medicine has been devoted to giving us a few extra precious months with grandma…not 100 more years. Barring some revolution along the magnitude of hand washing and efficient sewage systems, we’re not likely to see any significant change in the average.

But that doesn’t mean someone can’t live 200 years!

Well, those suggesting that are assuming away an important concept: maximum attainable age. Despite the upward, albeit slowing, trend in newborns’ life expectancies, our supercentenarians haven’t gotten any older (see Table 2). We’re just now more aware of their awesome presence thanks to birth registration and international media.

TABLE 2**


I’ll admit that we haven’t yet given the babies who received the largest gains in life expectancy a chance to break the world record. Maybe I’m already biased against them, believing since my childhood that the Bible sets the highest average lifespan at 80 (Psalm 90:10) and the maximum attainable age at 120 (Genesis 6:3), give or take a few years to compensate for ancient reckoning of age. (I’ll admit there’s good reason not to take the first passage literally!) However, I have thought of how some other data might clue us into the likelihood of anyone today breaking 122. Stay tuned for Part 2.

*TABLE 1. Data series constructed from “Table Ab644-655 : Expectation of life at birth, by sex and race: 1850-1998,” Historical Statistics of the United States Millennial Edition Online (2006); “11. Life expectancy by age, race, and sex: Death-registration states, 1900–1902 to 1919–1921, and United States, 1929–1931 to 2006,” “United States Life Tables, 2006,” National Vital Statistics Reports, Vol. 58, No. 21, (June 28, 2010).

**TABLE 2. Life expectation data series constructed from “Table Ab644-655 : Expectation of life at birth, by sex and race: 1850-1998,” Historical Statistics of the United States Millennial Edition Online (2006); “11. Life expectancy by age, race, and sex: Death-registration states, 1900–1902 to 1919–1921, and United States, 1929–1931 to 2006,” “United States Life Tables, 2006,” National Vital Statistics Reports, Vol. 58, No. 21, (June 28, 2010). Highest age data series constructed from “Chronological list of the verified oldest living person since 1955,” “Oldest People,” Wikipedia (Accessed August 24, 2010); “Supercentenarians who died before 1955,” “Oldest People,” Wikipedia (Accessed August 24, 2010). Note: Non-Americans are included in the lists of oldest people.