Could Immortality Be Within Grasp? Scientists Say Yes
When cervical cancer killed Henrietta Lacks in 1951, no one guessed she would achieve a strange kind of immortality.
Yet today, nearly half a century later, the cancer cells that killed Lacks live on in laboratories around the world--long after most human tissue would have reached old age and stopped reproducing.
As far as anyone can tell, these so-called HeLa cells are immortal. Given the proper conditions, cell biologists say, the cells will simply go on growing and replicating forever.
To researchers studying human aging, the example of the HeLa cells poses a fundamental question: If human tissue cells can live indefinitely, why not people?
The answer may be near. A vast array of research projects is providing stunning new insights into why the human body grows old and dies--and how it might live on instead.
Doctors and scientists, taking advantage of some of the latest medical breakthroughs, are unearthing tantalizing clues about how the aging process can be slowed and perhaps even stopped.
Their work raises the prospect that, within the next decade or two, humans could routinely live to age 100 and beyond. Better yet, they could do so with the health and vitality now associated with many people in their 60s and 70s.
“Within 10 years, we’ll be able to prove that we can extend life span, and prevent aging diseases and what we know of as the aging process,” said Dr. Michael Fossel, editor of the Journal of Anti-Aging Medicine.
Indeed, some observers are even suggesting that humans--like the HeLa cells--might one day conquer death itself.
“Today, we face the Grim Reaper whether we want to or not,” said Ben Bova, author of the upcoming book “Immortality: How Science Is Extending Your Life Span--and Changing the World.”
“But in the very near future, perhaps in a decade or less, we’ll be able to push that moment of reckoning off for a very long time. And perhaps we’ll eventually be able to push that off indefinitely,” he said.
People Living Longer
Medical science has already made astounding progress in lengthening human life expectancy.
Consider that as recently as 1850, the average American lived only until about age 38. By 1900, that number had jumped sharply, bringing average life expectancy to age 50. Since then, life expectancy has increased 50% more; Americans now live to be about 75.
But the averages tend to mask the large and growing numbers of people who live longer still. Centenarians--people 100 and older--are now the fastest-growing age group in America. They’re closely followed by people older than 80.
Even so, most people never approach what is currently regarded as the limit of the human life span: roughly 120 years. (The longest recorded human life was that of Jeanne Louise Calment, who died last August in France at 122.)
Most progress in extending life expectancy has resulted not from antiaging research but from preventing premature death. Antibiotic drugs, better sanitation, better nutrition and improved safety have all helped reduce the number of people who die young.
Recently, however, researchers have begun taking aim at the very process of aging itself--a quest that could increase both life expectancies and life spans.
“It’s totally possible that we have within our hands the technology of preventing human aging,” said Michael West, chairman of Origen Therapeutics, a San Francisco biotechnology company.
The effort represents a fundamental shift in how some scientists approach antiaging research. Instead of seeing aging as the natural consequence of a long life, these researchers regard aging itself as a disease, one that can be successfully treated and perhaps even “cured.”
“The biotechnology explosion . . . is almost 100% involved in antiaging medicine. It’s hard to think of a technological innovation coming out of the laboratory today that doesn’t have some immediate application to enhancing the quality or increasing the quantity of the human life span,” said Dr. Ronald Klatz, president of the American Academy of Anti-Aging Medicine.
“The real imperative right now is to keep yourself in good shape for the next 10 to 20 years in order for these technologies to become matured,” he said.
Cell Research
One of the most promising lines of research is into a part of the human cell called a telomere. Some scientists believe these telomeres hold key secrets to why cells--and ultimately, people--age and die.
A telomere is a kind of cap that forms around the chromosomes in cells, protecting those chromosomes from damage, especially when the cell reproduces. Research shows that every time the cell divides, the telomeres get a little shorter.
When the telomeres reach a certain critical length, the cell no longer can divide properly. Somehow, the cell recognizes this and begins to self-destruct.
This limit on the number of times human cells can divide has been known for nearly four decades. But it is only in the past year that scientists for Geron Corp. and at the University of Texas Southwestern Medical Center have discovered a way to short-circuit that process.
These researchers found that when they inserted “telomerase,” a special enzyme that rebuilds telomeres, into human cells, the result was longer telomeres and longer cell life in laboratory experiments.
“We think it’s arguably one of the most important achievements in our understanding of the biology of cell aging,” said Ron Eastman, Geron chief executive.
But even some who acknowledge the value of the research have doubts about whether telomere manipulation will prove to be a “magic bullet” against aging.
“We don’t know whether that’s what really limits our life span. It’s just what you might call an exciting possibility,” said Jason Wolfe, a specialist in cell biology at Wesleyan University.
Plenty of other antiaging treatments are being studied as well. Among them are anti-oxidant vitamins, replacement hormones such as DHEA, melatonin and human growth hormone, and dietary restrictions.
Meanwhile, much other research is directed at helping people remain healthy for a greater percentage of their current life span. Indeed, many researchers believe the focus should be on increasing the “health span,” not life span.
That means tackling such conditions as arthritis, hypertension, cancer, stroke, Alzheimer’s disease, bone loss, failing eyesight and hearing.
