One of the ways in which technology is empowering ordinary people involves helping us to live longer. Aristocrats always had much longer and healthier lives than the common folks, who were (more or less literally) plagued with disadvantages such as poor nutrition, unhealthy living conditions, and overwork. There's no longer such a huge discrepancy among classes. As historian Robert Fogel notes:
[T]he life expectancy of the [British] lower classes increased from 41 years at birth in 1875 to about 74 years today, while the life expectancy of the elite increased from 58 years at birth to about 78 years. That is a remarkable improvement. Indeed, there was more than twice as much increase in life expectancies during the past century as there was during the previous 200,000 years. If anything sets the twentieth century apart from the past, it is this huge increase in the longevity of the lower classes. [1]
Now, however, technology seems likely to extend life expectancy even more -- decades or centuries more, while featuring vastly better health and vigor in the bargain. That seems like terrific news to me, but not everyone is so sure.
There is now some reason to think that life spans may become considerably longer in the not-too-distant future. Experiments with rats, fruit flies, and worms have demonstrated that relatively simple modifications ranging from caloric restriction to changes in single genes can produce dramatic increases in life span. So far, these haven't been demonstrated in human beings (whose long life spans make us harder to work with than fruit flies, for whom a doubling only lengthens the experiment for a few days), but many researchers believe that such improvements are feasible.
At the moment, both dietary and genetic approaches to increasing longevity have proved successful. As Richard Miller writes, "In the past two decades, biogerontologists have established that the pace of aging can be decelerated routinely in mammals by dietary or genetic means. . . . There is now . . . incontrovertible evidence, from many fronts that aging in mammals can be decelerated, and that it is not too hard to do this." [2]
Caloric restriction is probably the better-established of the two approaches. Animals fed diets that contain all necessary nutrients, but that provide substantially fewer calories than normal diets (and I mean substantially, as in 40-60 percent fewer), seem to lead longer and healthier lives:
Caloric restriction prolongs the life span by several different, but interrelated, mechanisms that attenuate oxidative stress. . . . The fundamental observation is that dietary restriction reduces damage to cellular macromolecules such as proteins, lipids, and nucleic acids.... Caloric restriction leads to reduction in cellular oxidants such as hydrogen peroxide and increases the activity of endogenous antioxidant enzymes. [3]
In fact, animals on reduced-calorie diets are healthier, not simply longer-lived:
Importantly, the CR diet does not merely postpone diseases and death; it seems to decelerate aging per se and in so doing retards age-related changes in (nearly) every system and cell type examined.... Calorie-restricted rodents remain healthy and active at ages at which control littermates have long since all died. . .. Autopsy studies of CR animals at the end of their life span typically show very low levels of arthritic, neoplastic, and degenerative change, and in functional tests of immunity, memory, muscle strength, and the like, they typically resemble much younger animals of the control group. [4]
No struldbrugs these. [5]
Some humans are experimenting with caloric restriction, but it does not seem likely to appeal to most people, as it may promise a long life -- but a hungry one. Still, it's promising for two reasons. Most obviously it indicates that the aging process -- often regarded with almost supernatural awe -- is in fact susceptible to change through rather simple and crude interventions. Additionally, it seems likely that many of the processes impacted by caloric restriction can be artificially induced by other means. [6]
Genetics also seems to offer hope. Some species are notably longer-lived than others, and it turns out that those long-lived species tend to have many genetic characteristics in common. While one might, via a sufficiently long-term breeding program, produce long-lived humans without any external interventions, doing so would take many generations. And inserting new or modified genes in human beings, though likely possible in time, is difficult and poses significant political problems.
Scientists are, however, already researching drugs that activate or deactivate existing genes in order to retard aging:
Once these two longevity extension mechanisms were identified, many scientists independently tried to develop pharmaceutical interventions by feeding various drugs suspected of regulating these two processes to their laboratory animals. Six of these experiments have shown various signs of success. Although these independent experimenters used different intervention strategies and administered different molecules to their laboratory animals, they each recorded significant increases in the animals' health span and/or a significant extension of the animals' functional abilities .... The pharmaceutical extension of longevity via a delayed onset of senescence has been proved in principle by these six experiments despite their individual limitations. [7]
Biogerontologists like Cambridge University's Aubrey de Grey are looking at far more dramatic interventions that would not merely slow the aging process, but stop or even reverse it, through eliminating DNA damage, replacing senescent cells with new ones, and so on. [8]
But won't we wind up with lots of sick old people to look after? No. In fact, we're actually likely to see fewer people in nursing homes even though we'll have many more old people around. That's because (as in the experiments above) people will be younger, in terms of both health and ability, for their ages. And, after all, who would buy a treatment that just promised to extend your drooling years?
Government programs and pharmaceutical company researchers will likely aim at producing treatments resulting in healthy and vigorous oldsters, not struldbrugs, and it seems even more likely that people will be willing to pay for, and undergo, treatments that promote youth and vigor, but not treatments that simply prolong old age. Today's approach of incremental, one-disease- at-a-time medical research does nothing to help old people in terrible condition, still around simply because they're not quite sick enough to die yet. Genuine aging research is likely to produce a different outcome, restoring youth and health. If it can produce treatments or medications that let people enjoy a longer health span -- more youth, or at least more middle age, by several decades -- then those treatments will sell. If not, then there won't likely be much of a market for treatments that merely extend the worst part of old age.
LADIES, MEET DON JUAN SR.
Thus, if we can expect anything, we can expect treatments that give us more of the good part of our lives -- anywhere from a couple of extra decades to, at the most optimistic end, several extra centuries. And who could be against that?
Well, Leon Kass, the chair of the White House Bioethics Council during President Bush's first term and into the second, for one. "Is it really true that longer life for individuals is an unqualified good?" asks Kass, tossing around similar questions. "If the human life span were increased even by only twenty years, would the pleasures of life increase proportionately? Would professional tennis players really enjoy playing 25 percent more games of tennis? Would the Don Juans of our world feel better for having seduced 1250 women rather than 1000?" [9]
To me, it seems obvious that the answer to all these questions is yes. To Kass, it would seem, the answer is obviously no. But as it happens, we've conducted an experiment along these lines already, and the outcome is not in Kass's favor.
Life spans, after all, have been getting steadily longer since the turn of the twentieth century. According to the Centers for Disease Control, "Since 1900, the average life span of persons in the United States has lengthened by greater than thirty years." [10] That's an average, of course. Nonetheless, there are a lot more old people than there used to be, and they're working longer. Indeed, as Discover magazine has observed, ''A century ago, most Americans lived to be about fifty. Today people over a hundred make up the fastest-growing segment of the population." [11] You can argue about the details, but it's clear that typical adults are living longer than at any time in human history.
So we've already tested out an extra twenty years of healthy life, more or less. And yet people -- far from being bored, as Kass suggests they should be -- seem quite anxious to live longer, play more tennis, have more sex, and so on. The market is proof of that: although it possesses little scientific basis at the moment, so-called "anti-aging medicine" is a rapidly growing field -- rapidly growing enough, in fact, that biogerontologists fear it will give legitimate research in the field a bad name. [12] (That's proof that there's demand out there, anyway.) Nor does one hear of many otherwise healthy people who are anxious to die, even at advanced ages, out of sheer boredom. Instead, they seem eager to improve their lives, particularly their sex lives, as the booming sales of drugs like Viagra and Cialis indicate.
One might argue -- and in fact bioethicist Daniel Callahan does argue -- that these desires are selfish and will be satisfied at the expense of society as a whole. [13] All of those perpetually young oldsters, after all, will refuse to retire, and society will stagnate. [14]
That sounds plausible. But greater life expectancy is not the only recent achievement: the past hundred years have also been the most creative and dynamic period in human history. And our institutions certainly aren't controlled by a rigid gerontocracy. (In fact, one finds rigid gerontocracies mostly in communist countries -- the former Soviet Union, the current People's Republic of China -- not in capitalist democracies. So those who fear gerontocracy might do better by opposing communism than aging research.)
At any rate, I'm not too worried. The tendency in America seems to be toward more turnover, not less, in major institutions, even as life spans grow. CEOs don't last nearly as long as they did a few decades ago. University presidents (as my own institution can attest) also seem to have much shorter tenures. Second and third careers (often following voluntary or involuntary early retirements) are common now. As a professor, I see an increasing number of older students entering law school for a variety of reasons, and despite the alleged permanence of faculty jobs, more than half of my law faculty has turned over, in the absence of mandatory retirement, in the fifteen years that I have been teaching. And we've seen all of this in spite of longer lives, and in spite of the abolition of mandatory retirement ages by statute over a decade ago. [15] This is more dynamism, not less.
To his credit, Callahan says that he doesn't want to ban life-extension research or treatment: "I would not want to prohibit the research. I want to stigmatize it. I want to make it look like you are being an utterly irresponsible citizen if you would sort of dump this radical life extension on the rest of us, as if you expect your friends and neighbors to pay for your Social Security at age 125, your Medicare at 145." [16]
He's wise not to suggest a ban. It seems likely that such a ban on life-extension research or treatments would be unconstitutional, in light of the rights to privacy, medical treatment, and free speech established in a number of Supreme Court opinions. As a result of cases like Lawrence v. Texas [17] or Griswold v. Connecticut [18] that establish people's right to control their own bodies, and to pursue courses of medical care that they see as life-enhancing without moralistic interference from the state, such a ban would likely fail. (Would it make a difference that the Supremes tend to be rather long in the tooth? Maybe.)
It seems even more likely, however, that such a ban would be unpopular (and surely even the most hardened supporter of Social Security and Medicare would blanch at the claim that those programs create a moral obligation to die early on the part of their recipients). Nor does it seem likely that if life were extended to such lengths people would want to retire early and collect Medicare.
WHY RETIRE?
Today's notion of "retirement age" is a fairly recent one. Otto von Bismarck is often credited with craftily setting the retirement age at sixty-five because most people wouldn't live that long -- though in fact, Bismarck set it at seventy and it wasn't lowered to sixty-five until later. [19] But the justification for retirement has always been that by retirement age people were nearly used up and deserved a bit of fun and then a comfortable and dignified decline until death. Get rid of the decline and death, and you've given up the justification for subsisting -- as Social Security recipients, at least, do -- off other people's efforts on what amounts to a form of welfare. Logically, retirement should be put off until people are physically or mentally infirm (and perhaps retirement should just be replaced entirely with disability insurance). Those who are able to work should do so, while those desirous of not working should save up as for a long vacation. Alan Greenspan -- the very model of combined productivity and longevity -- has argued repeatedly for extending retirement ages in tandem with increasing life expectancies, and it is possible that in some non-election year his advice may be followed. [20]
In this regard, increased longevity, with (at the very least) much higher retirement ages, could be the salvation of many nations' pension systems, which to varying degrees are facing an actuarial disaster already as the result of longer life spans and lower retirement ages, coupled with lowered birthrates. [21]
Indeed, although many people worry that longer life spans will lead to overpopulation, the world is now facing what Phillip Longman, writing in Foreign Affairs, calls a "global baby bust." [22] Longer lives and later retirements will help offset at least some of the consequences of falling birthrates -- and people who expect to live longer might be more willing to take time out to bear and raise children, without feeling that it's such a career sacrifice to do so.
But what's surprising to me is that so many people see the idea of living longer as controversial, even morally suspect. Part of this, I suspect, has to do with the usual skepticism regarding the new. Ron Bailey notes:
As history demonstrates, the public's immediate "yuck" reaction to new technologies is a very fallible and highly changeable guide to moral choices or biomedical policy. For example, in 1969 a Harris poll found that a majority of Americans believed that producing test-tube babies was "against God's will." However, less than a decade later, in 1978, more than half of Americans said that they would use in vitro fertilization if they were married and couldn't have a baby any other way. [23]
In fact, as Bailey also notes, many of those who oppose longer lives -- including, for example, Leon Kass -- previously opposed in vitro fertilization too. [24] They tend not to bring that subject up on their own now, though. And that's not all:
New medical technologies have often been opposed on allegedly moral and religious grounds. For centuries autopsies were prohibited as sinful. People rioted against smallpox vaccinations and opposed the pasteurization of milk. Others wanted to ban anesthesia for childbirth because the Bible declared that after the Fall, God told Eve, "In sorrow thou shalt bring forth children" (Gen. 3: 16). [25]
I suspect that people's inherent suspicion of longer life will fade too. In mythology, longer life is always offered by a supernatural force, with a hidden and horrible catch somewhere: you have to surrender your soul, or drink the blood of virgins, or live forever while growing more feeble. Or, in real life as opposed to mythology, such a prize was offered to the desperate and gullible by charlatans who couldn't deliver on their promises anyway.
Of course, cures for baldness and impotence used to be the domain of charlatans too (though they got less attention from evil deities). Now they're cured by products available in pharmacies, sometimes without a prescription. People may joke about Viagra or Rogaine, but they don't fear them. I suspect that's how treatments for extending our lives will come to be seen -- unless those who oppose them manage to get them outlawed now, while they can still capitalize on people's inchoate fears. I doubt they'll succeed. But I'm sure they'll try.
AFTERWORD: AN INTERVIEW ON IMMORTALITY
Aubrey de Grey is a biogerontologist at Cambridge University in England, whose research on longevity -- via an approach known as "Scientifically Engineered Negligible Senescence" -- has gotten a great deal of attention. I think that this subject is on the technological (and political) cusp, and that we'll be hearing more about it, so I interviewed him (via email).
Reynolds: What reasons are there to be optimistic about efforts to slow or stop aging?
de Grey: The main reason to be optimistic is in two parts: First, we can be pretty sure we've identified all the things we need to fix in order to prevent -- and even reverse -- aging, and second, we have either actual therapies or else at least feasible proposals for therapies to repair each of those things (not completely, but thoroughly enough to keep us going until we can fix them better). The confidence that we know everything we need to fix comes most persuasively from the fact that we haven't identified anything new for over twenty years.
Reynolds: What do you think is a reasonable expectation of progress in this department over the next twenty to thirty years?
de Grey: I think we have a 50/50 chance of effectively completely curing aging by then. I should explain that I mean something precise by the suspiciously vague-sounding term "effectively completely." I define an effectively complete cure for aging as the attainment of "escape velocity" in the postponement of aging, which is the point when we're postponing aging for middle-aged people faster than time is passing.
This is a slightly tricky concept, so I'll explain it in more detail. At the moment, a fifty-year-old has roughly a 10 percent greater chance of dying within the next year than a forty-nine-year-old, and a fifty-one-year-old has a 10 percent greater chance than a fifty-year-old, and so on up to at least eighty-five to ninety (after which more complicated things happen). But medical progress means that those actual probabilities are coming down with time. So, since we're fifty only a year after being forty-nine, and so on, each of us has less than a 10 percent greater chance of dying at fifty than at forty-nine-it's 10 percent minus the amount that medical progress has achieved for fifty-year-olds in the year that we were forty-nine. Thus, if we get to the point where we're bringing down the risk of death at each age faster than 10 percent per year, people will be enjoying a progressively diminishing risk of death in the next year (or, equivalently, a progressively increasing remaining life expectancy) as time passes. That's what I call "escape velocity," and I think it's fair to call it the point where aging is effectively cured.
Reynolds: What sort of research do you think we should be doing that we're not doing now?
de Grey: Well, there are several approaches to curing aspects of aging that I think are very promising, but which most people seem to think are too hard to be worth trying. One is to obviate mitochondrial mutations, by putting suitably modified copies of the thirteen mitochondrial protein-coding genes into the nucleus. This is hard -- some of those suitable modifications are hard to identify -- but it's definitely feasible. A second one is to find enzymes in bacteria or fungi that can break down stuff that our cells accumulate because they can't break it down, like oxidized cholesterol. The idea here is to put such genes into our cells with gene therapy, thereby enabling them to break the stuff down. If we could do that, it would virtually eliminate strokes and heart attacks; and similar approaches could cure all neurodegenerative diseases and also macular degeneration, the main cause of age-related blindness. A third one is to look for chemicals or enzymes that can cut sugar-induced cross-links (advanced glycation end products). One such compound is known, but it only breaks one class of such links so we need more, and no one is really looking. And maybe the biggest of all is to cure cancer properly, by deleting our telomere-maintenance genes and thereby stopping cancer cells from dividing indefinitely even after they've accumulated lots and lots of mutations.
Reynolds: Some people regard aging research, and efforts to extend life span, with suspicion. Why do you think that is? What is your response to those concerns?
de Grey: I think it's because people don't think extending healthy life span a lot will be possible for centuries. Once they realize that we may be able to reach escape velocity within twenty to thirty years, all these silly reasons people currently present for why it's not a good idea will evaporate overnight. People don't want to think seriously about it yet, for fear of getting their hopes up and having them dashed, and that's all that's holding us back. Because of this, my universal response to all the arguments against curing is simple: don't tell me it'll cause us problems, tell me that it'll cause us problems so severe that it's preferable to sit back and send 100,000 people to their deaths every single day, forever. If you can't make a case that the problems outweigh 100,000 deaths a day, don't waste my time.
Reynolds: What are some arguments in favor of life extension?
de Grey: I only have one, really: It'll save 100,000 lives a day. People sometimes say no, this is not saving lives, it's extending lives, but when I ask what the difference is, exactly, no one has yet been able to tell me. Saying that extending old people's lives is not so important as extending young people's lives may be justified today, when older people have less potential life to live (in terms of both quantity and quality) than younger people, but when that difference is seen to be removable (by curing aging), one would have to argue that older people matter less because they have a longer past, even though their potential future is no different from that of younger people. That's ageism in its starkest form, and we've learned to put aside such foolish things as ageism in the rest of society; it's time to do it in the biomedical realm too.
Reynolds: Do you see signs of an organized political movement in opposition to life extension?
de Grey: No, interestingly. I see people making arguments against it, and certainly some of those people are highly influential (Leon Kass, for example), but really they're just using life extension as a vehicle for reinforcing their opposition to things that the public does realize we might be able to do quite soon if we try. They get the public on their side by exploiting the irrationality about life spans that I've described above, then it's easier to move to other topics.
Reynolds: For that matter, do you see signs of an organized movement in support of such efforts?
de Grey: Oh yes. There are really only isolated organizations so far, but they are increasingly cooperating and synergizing. The older ones, like the cryonics outfits and the Life Extension Foundation, are as strong as ever, and they're being joined by other technophile groups like the Foresight and Extropy Institutes and the World Transhumanist Association, plus more explicitly longevity-centric newcomers such as the Immortality Institute. Quite a few blogs are helping this process along nicely, especially Fight Aging! and Futurepundit, and I really appreciate that you're now among them. And of course there's the organization that I cofounded with David Gobel a couple of years ago, the Methuselah Foundation, which funds some of my work through donations but whose main activity is to administer the Methuselah Mouse Prize. [A prize of over $1 million for extending the life of laboratory mice beyond the present record.]
Reynolds: What might life be like for people with a life expectancy of 150 years?
de Grey: Well, we won't have a 150-year life expectancy for very long at all -- we'll race past every so-called "life expectancy" number as fast as we approach it, as outlined above. So maybe I should give an answer to the analogous question regarding indefinite life spans. Life will be very much the same as now, in my view, except without the frail people. People will retire, but not permanently -- only until they need a job again. Adult education will be enormously increased, because education is what makes life never get boring. There will be progressively fewer children around, but we'll get used to that just as easily as we got used to wearing these absurd rubber contraptions whenever we have sex just in order to avoid having too many kids once infant mortality wasn't culling them any more. Another important difference, I'm convinced, is that there will be much less violence, whether it be warfare or serious crime, because life will be much more valued when it's so much more under our control.
Reynolds: What is your response to concerns that life extension therapies might be too expensive for anyone but the rich?
de Grey: This is a very legitimate concern, which society will have to fix as soon as possible. Since 9/11 we all know how bad an idea it is to make a lot of people really angry for a long time -- if the tip of that anger iceberg is willing to sacrifice everything, lots of other people lose everything too. Since rich people will be paying for rejuvenation therapies as a way to live longer, not as a way to get blown up by poor people, everyone will work really hard to make these treatments as cheap as possible as soon as possible. That'll be a lot easier with a bit of forward-planning, though -- e.g., an investment in training a currently unnecessary-looking number of medical professionals. But one way or another, these treatments will definitely become universally available in the end, probably only a few years after they become available at all, even though the cost of doing this will be staggering. The only way to have a sense of proportion about this period is to remember that it'll be the last chapter in what we can definitely call the War on Aging -- people worldwide will readily make the same son of sacrifices that they make in wartime, in order to end the slaughter as soon as possible.
Reynolds: Leon Kass has suggested various items of literature as cautionary tales. What literary or science fiction stories might you recommend for people interested in this subject?
de Grey: I used to give the obvious answer to this -- [Robert A.] Heinlein. But now I have a new answer. Nick Bostrom, a philosopher at Oxford University here in the UK, has written a "fairy tale" about a dragon that eats 100,000 people a day and its eventual slaying. It's been published in the Journal of Medical Ethics, but it's also online in a great many places, including his website [http://www.nickbostfom.com]. It's absolutely brilliant.