Life expectancy has already steadily increased in the past century from 47 to 77 years. But thats measured from birth and is almost entirely because more people are living to become old, rather than older people living longer. Essentially, its a measurement of a dramatic drop in infant mortality. But the new treatments will actually extend lifespan, far beyond the widely-accepted 120-year limit.
One approach to literally reversing aging involves telomeres. These are tightly coiled threads of DNA that form a protective cap on the ends of each of our chromosomes. The DNA shortens each time the cell divides until the cell cannot divide anymore. Then our bodies start to decline.
But scientists from Geron Corporation and the University of Texas Southwestern Medical Center in Dallas showed in the lab that by adding the enzyme telomerase to human cells, they could make them into little Eveready Bunnies. They just kept on dividing and dividing.
In one case, scientists extended the life of a mouse to five years – 180 years in human terms.
But scientists are following many longevity paths. By my latest count, there were about eight sets of researchers working on eight different ways of manipulating genes to allow us to live longer. Far longer.
For example, Italian researchers have created what they dubbed "Methuselah Mice" after the person in Genesis said to have lived 969 years (and who personally bankrupted the Social Security and Medicare systems of his time.)
These rodents lived a third longer than normal apparently for no other reason than that one of their genes had been switched off. Its too early to say for sure, but it appears this particular gene tells the bodys cells to die. It also seems to play a role in cancer, so eliminating it may independently reduce the risk of malignancies.
And in case youre wondering, flipping genes on or off is not rocket science. It can often be done with the application of a simple drug like tetracycline.
Will the Italian experiment lead to an approved human therapy? Most rodent successes dont survive the arduous journey through human clinical trials that must demonstrate the treatment to be both safe and effective. But with so many labs following so many paths and new paths being discovered, inevitably some will succeed.
Further, "I dont think a 30 to 40 percent [increase in lifespan]
should be considered as some kind of maximum," according to Dr.
Tomas Prolla, a geneticist specializing in aging at the University
of Wisconsin at Madison.
Another route to the same end involves the long-observed phenomenon that creatures from worms to mammals live much longer if placed on a severely calorie-restricted diet. Its assumed this would work in humans, but to what avail in a country where two-thirds of us are overweight?
MIT professor Leonard Guarente, however, wants us to have our cake and live longer too. Hes discovered a gene called Sir2 that appears to keep in check many other genes that promote aging. But Sir2 is also involved in metabolism, so overloading it with more than a bare minimum of calories keeps it from its anti-aging task.
The Sir2 thesis hasnt yet been tested in animals, but as University of California, San Francisco biochemist Cynthia Kenyon said regarding genetic regulation of aging, if "it happens in both worms and fruit flies, you have to be crazy to think it wont happen in vertebrates."
Dont expect any of the gene-related anti-aging therapies to be marketed for a decade, but there may be something you can buy right that could put off that date with the grim reaper.
A process called oxidation, in which loose electrons bouncing around our cells and wreak havoc, promotes both aging and cancer. "In essence, were rusting, says renowned Berkeley biologist Bruce Ames. But do antioxidant supplements slow that process?
No one can say for sure yet, but many studies have shown antioxidants to be effective in warding off diseases closely tied to aging. One recent 16-month study of Parkinsons patients showed that those taking high doses of the antioxidant coenzyme Q-10 had an astounding 44 percent less decline in mental function, movement and ability to perform daily living tasks than the placebo group.
Ames himself has developed a supplement combining a powerful antioxidant plus an antioxidant promoter, sold under the brand name Juvenon. He concedes he doesnt know yet how much it will help humans but its worked wonders in numerous rat tests. "They could get up and do the Macarena," Ames says.
Perhaps, though Ive been taking Juvenon since it was introduced and still havent learned the Macarena. But based on the available studies I also take the antioxidants coenzyme Q-10, selenium, vitamin B-complex, and vitamins C and E.
Moreover, we wont be spending the last third of our 150-year lives slobbering
on ourselves in a wheelchair. This is a worry Francis Fukuyama expressed
in his anti-biotech book Our
Posthuman Future: Consequences of the Biotechnology Revolution,
aptly summarized in a Nature Biotechnology review
as seeking "to arouse fear: fear of science, fear of individual choice,
fear of the future."
Rather, each of the therapies described or alluded to in this article wont just extend life but also extend the period of time before decrepitude.
Because theres been so much talk of biotech anti-aging breakthroughs, it was probably inevitable that naysayers would pop up to say its all bunkum. Nobody in our generation, or even our childrens generation, will live significantly longer than they do now, they insist.
We dont know yet whether antioxidants extend human life, but taken as supplements to a good overall diet it appears quite possible.
France and Japan will not reach a life expectancy at birth of 100 years until the 22nd century, he said, while Americans wont hit the century mark until the 26th century. "The rise in life expectancy in the future will be measured in days, weeks and months – not in decades, as some proponents of extreme longevity predict."
But making predictions about the condition of the human race in 500 years readily pulls you out of the "scientist" class and plunges you smack into the realm of Nostradamus. All Olshansky and his fellow nay-centenarians are doing is using circular reasoning along the lines of, "Ive never been in a fatal accident; therefore I never will be in a fatal accident." More specifically, theyre simply looking at past trends.
Imagine a similar projection of electronic technology from 40 years ago. Virtually nobody would have conceived of desk-top computers that double in speed every 12-18 months, or bandwidth that doubles far faster, or the Internet itself. Yet Olshansky is willing to make a prediction for half a millennium from now.
Similarly, Leonard Hayflick of the University of California at San Francisco, one of the leading figures of gerontology, wrote in Nature magazine in November of 2000, "There is no evidence to support the many outrageous claims of extraordinary increase in human life expectancy that might occur in our lifetime or that of our children." His evidence? Extrapolation of data from the U.S. Census Bureau, the U.S. Social Security Administration, and from a group of the worlds industrialized countries. This says nothing more than "since there were no breakthroughs in the last 20 years, there will be none in the next 20 years." How many people must have said the same thing about baldness remedies?
And shortly after Hayflicks commentary appeared, researchers in Science magazine announced that by causing a gene mutation they succeeded in getting fruit flies to live as much as 85 percent longer. "Whats exciting about these findings is that they suggest that there is a genetic system common to all animals that regulates aging," lead author David Gems of University College London told Reuters Health. "If we could just tap into the mammalian version of that system it might be possible to retard or even reverse human aging."
Claiming that all of the anti-aging work described here will pan out would be foolish indeed. But claiming that absolutely none will is far more so. In part, thats because lifespan extension is a goal that to many of us has an incredibly high value and offers research institutions and companies awesome financial incentives.
Oracle software CEO Larry Ellisons philanthropy alone, the Ellison Medical Foundation, is granting awards of about $20 million yearly to promising anti-aging projects. While most of the foundations money goes to infectious disease research, Ellison has plenty of billions more to plow into both. Thus far, however, his limit is probably not his generosity but rather the size of the scientific community working on aging-related therapies. But thats changing.
"Aging [research] used to be a stepchild, but now a lot of good people are finally getting into it," Ames told me. As the population ages, longevity research will become more and more attractive to scientists. It all creates an expanding "virtuous circle." "Biology – including longevity research – is going like a rocket now with help from the genomics revolution and computers," says Ames.
Visit Michael Fumentos biotechnology web site, BioEvolution.org.
"People tend to underestimate how fast the aging field is moving," adds MITs Leonard Guarente. "Were uncovering the molecular basis of aging. No, were not at a point where we can intervene in humans yet. But we have every reason to be hopeful that day will come."
None of this is to be confused with immortality, the quest for which greatly concerns Leon R. Kass, chairman of the Presidents Council on Bioethics. Kass says society should "resist the siren song of the conquest of aging and death." But his argument concerning aging really doesnt come down to much more than "It just doesnt seem right somehow."
As to immortality, Kass need not fear. Even reversing aging cannot confer eternal life. There are creatures that appear to be genetically programmed to live indefinitely, but something always catches up to them. With a tree it could be a disease, fire, or a chainsaw. With a lobster it could be a trap. Immortality means eternity, and as a subset of infinity 150 years is the same as 75.
But Kass is right to say that lifespan extension isnt inherently a good thing. Personally Id rather see a therapy that compels people to make better use of the lifespans they have, rather than waste them watching each new "Meet Joe Millionaire for the 10th time" or "Americas Funniest Home Autopsies." But like all biotechnology, lifespan extension is merely a tool. Its up to us how its used.Read Michael Fumentos additional work on biotechnology.