Friday, 16 May 2014
Extending the Human Lifespan
[EDITORIAL NOTE: This post is wonkier than you usually find on TGB but I think it is remarkable that in a short period of time new research has shot down three venerable areas of longevity research – something that should be noted, I think, on a blog about aging. Maybe you will find it as interesting as I do.]
Rumors of fountains of youth go back as least as far as 500 BCE and the notion of eternal life is a staple of literature.
For many years, decades in fact, scientists have been spending millions of research dollars – make that billions over time – looking for a modern fountain of youth. One of the most well-known, Aubrey deGray, believes humans can be made to live for as long as 200 years.
Back in 2008, I was privileged to interview respected geriatrician Robert N. Butler, the man who coined the term “ageism” and who devoted his career to improving the lives and health of elders. I asked him about these research efforts:
RB: What is your view of Aubrey deGray and others who believe human life can be extended for up to 200 years. Is this a worthwhile goal?
RNB: I think the extravagant claims for longer life by people like deGray are questionable, indeed. We do know that it is increasingly likely that we will be able to slow aging while at the same time delay the onset of diseases. This means that we should devote new financial resources to understanding the basic biology of aging, but we should not get carried away.
Yes, indeedy and some are doing as the late Dr. Butler advised while others continue to follow in the footsteps of Ponce de Leon, as we shall see.
But first, here is a nifty little video posted late last year explaining some of the biology of aging (hint: we don't know much about it at all) and how lifespans might be increased.
Integrative Biologist Joao Pedro de Magalhaes is the narrator. It is produced by +Piled Higher and Deeper (PHD Comics) in partnership with the Integrative Genomics of Ageing Group at the University of Liverpool Liverpool.
Did you notice all the “probably” statements in that video? More interesting is the assertion that “we know” calorie restriction extends lifespans in rodents by 50 percent.
Uh, not so fast. Although you should go read the full report for more nuanced details, those claims for mouse caloric restriction as possibly applied to humans ran into contradictions two years ago:
”...there is a dearth of evidence that caloric restriction slows ageing in humans. Observational studies have found that people of average weight tend to live longest.
“Nir Barzilai, a gerontologist at Albert Einstein College of Medicine in New York, says that the centenarians he studies have led him to believe that genetics is more important than diet and lifestyle. 'They’re a chubby bunch,' he says.”
You might have caught a reference to resveratrol in the video. It is a compound that occurs in red wine, peanuts, some berries and dark chocolate which researchers have spent years hoping to show that it helps prevent cancers, heart disease and, most exciting to the researchers, extends lifespan.
As it turns out, however. probably not - as the journal JAMA Internal Medicine reported when it published the results of a study at Johns Hopkins partially funded by the U.S. National Institute of Aging:
"In conclusion, this prospective study of nearly 800 older community-dwelling adults shows no association between urinary resveratrol metabolites and longevity. This study suggests that dietary resveratrol from Western diets in community-dwelling older adults does not have a substantial influence on inflammation, cardiovascular disease, cancer or longevity."
And then there is the free radicals crowd who have long insisted that those molecules, also known as oxidents, should be avoided because they contribute to the aging process. Now, new research from McGill University in Canada reports just the opposite:
"People believe that free radicals are damaging and cause aging,” write the researchers, “but the so-called 'free radical theory of aging' is incorrect.
“We have turned this theory on its head by proving that free radical production increases during aging because free radicals actually combat - not cause - aging. In fact, in our model organism we can elevate free radical generation and thus induce a substantially longer life (of cells)."
This may have future application with neurodegenerative diseases.
The reason for most of the increase in life expectancy during the 20th century is a question of math: science reduced and/or eliminated many of the diseases of childhood so that fewer people died within the first year or two of life skewing the statistics and lifting the apparent life expectancy.
(As Wikipedia notes: “During the early 1600s in England, life expectancy was only about 35 years, largely because two-thirds of all children died before the age of four.”)
For many years, some scientists have been hard at work to accomplish similar results with the diseases of age – that is, cancer, heart disease, hypertension, diabetes, etc.
If preventions or cures cannot be found, the idea is to push the onset of those diseases into latest possible years of life. It would not necessarily add years to our lives but would improve the health and wellbeing of elders for longer. There has been some progress in that direction though not nearly enough.
That is why Dr. Butler called for more research into understanding the basic biology of aging. He said he had no reason to oppose work to increase longevity but he had reservations about it too.
In his 2008 book, The Longevity Revolution: The Benefits and Challenges of Living a Long Life, he seemed conflicted, dismissing longevity research in one breath while also seeing some hope for the ancient, magical idea of the fountain of youth:
”What is at issue is quality of life, especially the interrelationships of population with societal and natural resources. Until we can do better, it is probably just as well if we do not have a breakthrough in longevity.
“Or, perhaps, were we to have a breakthrough, would we move faster in making adjustments?
“...Enthusiasts over the future of cell, tissue, and organ replacement imagine successive, comprehensive reconstitutions of the body. Replacement or regenerative medicine would push death back, presumably indefinitely.
“One must not doubt the possibility of the unexpected in science and uneven evolution of knowledge.”
Undoubtedly so. But for now, that kind of progress appears to be repeatedly thwarted.
At The Elder Storytelling Place today, Richard Wiesenthal: Simplicity