End Times (The Telos of Telomeres)

For Aristotle, both ethics and politics flowed from the telos, the end or purpose of all things. In what may be record time for translating Nobel Prize benchwork to biotech snake oil, telomeres are the latest rage in high-tech diagnostics. Several startups are now pitching them as a way to tell your “biological age,” a new health metric that is as baffling as it is troubling.[1]

The 2009 Physiology or Medicine prize went “for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase.” Telomeres, as I wrote in 1991, are like aglets—the plastic tips on the ends of your shoelaces—for your chromosomes. They’re long stretches of repetitive DNA that essentially keep chromosome ends from unraveling. The thing is, unlike shoelaces, chromosomes duplicate themselves. They have to—otherwise half your cells would have no genes. And every time they do, because of one of those ubiquitous little design flaws that show there’s Nobody Home Upstairs, your telomeres get a tiny bit shorter. The telomere is therefore a sort of clock, ticking down the mitoses until a cell reaches the Hayflick Limit, at which point basically chromosomal Fukushima occurs. Telomerase counteracts that shortening in certain cell types, making those cells effectively immortal.

There have always been a few people who find it irresistible to think that cellular aging determines organismal aging. Seems logical, right? I mean, we all know an organism is made of cells. When you get old, doesn’t it have to be because your cells are getting old?

Well, sort of, sometimes, in some cases, but not in any simple way. Senescence is an incredibly complex process—and nowhere more so than in humans, naturally—and it mostly happens independently of your telomere length. It’s certain that your telomeres will be shorter when you’re old than they were when you were young, but old people can have long telomeres, and young people can have short ones. For that matter, short people can have old telomeres.

Further, cellular immortality is a mixed blessing, to say the least. On the one hand, slowing cellular senescence could in principle forestall certain degrading diseases of disintegration. On the other, there’s already a name for immortalized cells: cancer.

Anyway, cellular and organismal aging operate on different time scales, and the latter involves a lot of processes that have nothing to do with the former. To equate them is to confuse variation at two different levels—the same sort of error found in claims that racial differences in IQ result from genetics rather than systematic discrimination.[2]

That neat little fallacy is the foundation of the business plan at several new biotech companies, in Spain, Houston, and of course, in Menlo Park, CA. They claim to be able to take a few of your cells, open them like sacrificial goats, spread out their entrails, and tell you how old you “really” are. These new longevity companies claim to only be raising a warning flag, pointing you toward medical treatments you might want to consider.

A century ago, the Life Extension Institute had a similar model. The New York-based company offered medical exams, denying that they were offering any medical treatment. They pitched their product directly to individuals, but their biggest customers were employers and the many life insurance companies springing up in the Progressive Era. They eventually shut down in the wake of numerous lawsuits and accusations of fraud and misrepresentation. And LEI’s cofounder, Irving Fisher, went on to found the American Eugenics Society.[3]

For a few hundred bucks, these new companies will give you one-stop diagnostic shopping. With one measurement, they claim, they can tell you all sorts of things about your overall health and well-being. You even get to pick your metaphor: you either get a “wake-up call” about how fast you are really aging, or you can have your “check engine light” checked, according to spokesmen for the companies quoted in the Times article. The check-engine light in my car goes on for free, but after that I guess that in both cases it means a lot of expensive, computer-based diagnostics, and a lot of fervent hopes that all you did was pop a circuit-breaker.

Some of the scientists involved show a refreshing degree of candor. Jerry Shay, of UT Southwestern and on the board of the company Life Length (didn’t I get email from Nigeria about a similar product the other day?), acknowledged that although they won’t tell anyone how long they will live, insurance companies might want this information “to set rates or deny coverage.” In other words, they’re perfectly happy to sell the actuarial illusion that they can tell anyone how long they will live.

A Spanish telomerista, Maria Blasco, said the telomere test might prove helpful to people “especially keen on knowing how healthy they are.” Never mind the deeply problematic notion of playing to the fears of bored upper middle-class hypochondriacs; outside of a couple of risk factors for very specific and rare diseases, no one has any idea what this tells you about how healthy you are. But hard data and actual products tend to be hell on stock prices anyway.

Everyone got that? They’re telling us this is a scam. Now look, I am not saying these folks are dishonest, or even cynical. I think they are a bunch of basically honest scientists swayed by the allure of high-tech translational biomedicine. It’s the scientific version of the American Dream. And it comes with the always-handy Biomedical Moral Pass. It’s a great example of overfunded, overhyped science that benefits corporations and stockholders but may well do patients more harm than good.

The thing I wonder about most, though, is this idea of “biological age.” Apparently, the age I think I am—which I have until now naively correlated to the number of birthdays I’ve had, and never mind—is now “non-biological.” It’s like an acoustic guitar. There was no such thing as an acoustic guitar until the electric guitar was invented. All guitars were acoustic. Are there now multiple kinds of time—chronlogical, biological, and who knows what else—where I can be getting older in one dimension and younger in another? Have these biologists have actually reinvented time?

Or have they figured out what time really is? Is my chronological age now merely a figment, a simulacrum—a fictive representation of some supra-biological horological process? If so, I don’t think I like where this is going. We’re not headed down the sunny, leafy lane of, “You’re only as old as you feel! Have another bran muffin and go enjoy the morning.” This is more like the gray, trash-strewn alley of, “You poor dumb bastard. You only think you want to go to that punk show downtown this weekend. Sit down, shut up, and drink your Mylanta.”

It sounds like the beginning of the end.

[1] Andrew Pollack, “A blood test offers clues to longevity,” 2011-05-18 (http://nyti.ms/iIO3gv).
[2] In other words, conflating within-group and between-group variation. Whatever IQ is, it is highly heritable. But heritability is a measure of variation within a group. The heritability of IQ is different for different groups under different conditions. It simply cannot be used as a measure of how “innate” a trait is.
[3] I write about Fisher in chapter 2 of my forthcoming book, “A Science of Human Perfection.”

First post

Hello and welcome!

I’m glad to be the newest member of the ScienceBlog team. I am going to be writing mainly on genes,  genomes, heredity, and health. Subjects in the news today such as personal genomics, pharmacogenomics, and genetic screening and counseling all have strong historical roots. Examining them can really cut through the hype and illuminate the headlines. I’m going to try to add some depth and perspective–and hopefully some humor–to biomedical questions that affect us all.

Factlets: I’m on the faculty of Johns Hopkins University, where I teach courses on 20th century biomedicine, the history of genetics, and oral history. I have two degrees in biology and one in history. I’ve written a book on the geneticist Barbara McClintock and edited one on the Intelligent Design controversy. My current book project is a history of medical genetics. The working title is The Science of Human Perfection and it will be published by the good folks at Yale University Press.

I also like to write for wider audiences. I’ve published in the New York Times Book Review, Natural History, Science, New Scientist, and The Believer, and have been on National Public Radio.

I also blog over at the Philadelphia Area Center for History of Science, where I’m planning to focus on more historical, probably somewhat more scholarly material. I tweet @nccomfort and you can find some of my writings on academia.edu.

Okay, enough preamble. Let’s get started!

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