In both the online and print edition of the latest Economist, we have this delightfully positive little article, Towards Immortality. An excerpt:

There is no greater goal for transhumanism than the conquest of death. Some of the most controversial advocates of technological improvements to humans, including Ray Kurzweil, an American inventor and author, and Aubrey de Grey, a gerontologist and chairman of the Methuselah Foundation, argue optimistically that immortality may become achievable for people who are alive today. But even without the yet-to-be-invented technologies that they say will make this possible, there are good reasons why we can hope to live a lot longer.

The article goes on to discuss the proven anti-aging power of caloric restriction and resveratrol. It mentions something interesting I wasn’t aware of, that there’s work to develop drugs to activate the genes (sirtuin) that kick in during caloric restriction, while skipping the whole not-eating thing.

In caloric restriction, you eat less, so your body goes into starvation mode, where it tries harder to live longer at the expense of other things, like libido. The idea is that your body thinks that a famine is happening, and it puts a higher priority on living through the famine to reproduce another day rather than reproducing immediately.

Because sirtuin genes, when activated, can decrease sex drive and increase androgenous characteristics in either gender, sirtuin-targeting drugs wouldn’t be for everybody. However, it could lead to a drug that provably extends human lifespan by 30% – 50%.

Say, for example, that you’re a 25-year-old white American female. Here in 2006, your life expectancy is just over 80. So you might say that you can expect to live to sometime around 2051.

But not so fast. Average human lifespan has been increasing by more than 1/4 of a year per year throughout the 20th century, and it shows no signs of slowing down. This trend has continued for every year in the 21st century as well. When I was younger I was told that it can’t keep going forever, as the maximum theoretically possible human lifespan is in the neighborhood of 120, the lifespan of the longest-lived person at that time. But then I realized that the so-called theoretical limit was probably just derived from the latter figure. From the article:

Back in 1928, an American demographer, Louis Dublin, calculated that the upper limit on average life expectancy would be 64.8 years, a daring figure at the time, with American life expectancy then just 57 years. But now his figure looks timid, given that life expectancy for women in Okinawa, Japan, has passed 85.3 years, 20 years more than Dublin claimed possible. Also looking timid are the scientists who later predicted that life expectancy would nowhere pass 78 years (in 1952), 79 years (1980) and 82.5 years (1984).

Thanks to better nutrition and health care, we can safely assume that life expectancy will continue to increase by at least 1/4 of a year per year for many decades to come. Advances like sirtuin-targeting drugs, or the work done by our friends at the Methuselah Foundation, could present “game-changing” life-extension strategies that outperform the mere 1/4 per year trend. With tech like this, our 25-year old female would get 11 years of extra life from the ongoing trend, putting her life expectancy at 91, plus any qualitatively new ambitious anti-aging therapies, which could add an additional 30% – 50%, opening up the 100+ age range, and putting her estimated year of death at around 2070 or 2080 rather than 2050. And what about the possibility of entirely new therapies that blow the lid off a finite lifespan altogether? Actively supporting these initiatives is what transhumanism is all about.