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March 21, 2004
Longevity of Man - How long can we live?
Longevity ego blogged across the decades! In 1985 I wrote an essay on longevity and anti-ageing science for my first year biology course. In 1994 I updated it with new telomere information and posted it on my website and had it published in "The Sydney Futurian", the newsletter of the Sydney Futurian Science Fiction Society Today I did an RSS search on anti-ageing medicine and found "Anti-Aging Medicine & Science Blog":http://anti-ageing.us/2003_04_13_blog_archive.html , and lo and behold, they have "my article on longevity linked from the Futurian mirror site":http://members.optushome.com.au/aussff/longevity.html as one of their references! "The "Plausible Futures Newsletter":http://www.plausiblefutures.com/index.php?cat=6698&offset=20&ps=20 focus on large scale social change and the implications of emerging technologies on the world system." Their lens looks to the Futurian mirror of my article, too. This is enough to persuade me that I should be paid to write. The least I can do is blog this.Longevity of Man - How long can we live?
by Ian Woolf
"Man will never be contented until he conquers death." - Dr Bernard Strehler, 1977 According to Dr Walton of the CSIRO, an organism's life generally falls into the three phases: 1 growth 2 maintenance, and 3 aging. It has been the desire to remain or return to phase 2 that has kept Humanity on our millenia-long qquest for immortality. Scientists now have some understanding of aging and are actively seeking for ways to prevent or even reverse the process; some of the quite successfully, and all of them optimistically. Life-expectancy in Will Shakespeare's day was only about thirty years. In England in the 1880's, just over a century ago, it was less than forty years of life for the working class majority. In Australia in 1900, it was fifty-one. In Australia now, it is seventy-five for men, and eighty-one for women,; a rise of three years in the last decade. In the 1970's demographers realized that for older people life expectancy is rising. In 1975 a sixty-five year old man could expect another 13.1 years, in 1983 a man of 65 averaged 14.2 more years, and in 1993 he can expect 17.2 more years. Researchers think this is probably due to better education, nutrition and attention to personal health, as well as availability of medical treatment for fatal conditions. Yet individuals now in their seventies and eighties were born early this century and suffered poorer nutrition and living conditions than today. This implies that given modern high living standards, children growing now should survive well into their nineties. Free radicals are unstable molecules that cause aging according to Dr Denham Harman. They disrupt cells by robbing electrons from passing molecules and triggering destructive reactions. They are created by oxygen processing in the body, or by contact with smoke and smog. Older cells are packed with them. Anti-oxidants combat free radicals by making them more stable, and thus preventing them causing damage. Vitamins C and E, carotene, and lecithin are all anti-oxidants. Dr Harman says that anti-oxidants increase life expectancy by twenty percent or more. Cross-linkage of vital proteins and nuclei acids in and around body cells causes aging according to Dr Johann Bjorksten. Gradually, with the assistance of lead, cadmium, aluminium and free radicals, the proteins are bound into large aggregates which are irreversibly immobilized, and clog the cells, ultimately destroying them. In 1970 Dr Bjorksten isolated microenzymes from soil bacteria which penetrate and breakdown the aggregates allowing them to be excreted safely. A proposed "youth pill" would contain the microenzymes plus chelating agents to remove the metals, and antioxidants to prevent further cross-linkage. Dr Bjorksten predicts 800 year life spans, soon! A "death-hormone" is triggered at a genetically programmed time says Dr Denckla. The hormone is secreted by the pituitary gland after adolescence. The output increases with age, and progressively blocks the action of a thyroid hormone, vital to metabolism. Dr Denckla has delayed aging in rats by removing the pituitary and dosing them with other hormones. A death-hormone neutralizing drug says Dr Denckla, could add 30 years to human life expectancy. Dr Denckla left research in 1980 after his funding was cut. The thymus gland shrinks with age says Dr Goldstein. Thus thymosin, which it secretes, is reduced in supply, until at eighty years of age, the gland has vanished altogether and its supply is zero. Thymosin maintains the immunological system. As thymosin level falls, susceptibility to disease and cancer mounts rapidly. Thymosin injections would allow one to age gracefully, disease-free, although it is uncertain how much life would be extended. Metabolic toxins accumulate in our blood and slowly poison us according to Alexis Carrel. Dr Klebanhoff at the Lackland Airforce Medical Centre has a "total body washout" machine, which siphons off all blood and replaces it with an oxygen-carrying solution, then drains this and gives a complete transfusion. Replacement blood would preferably be from healthy young donors, or have been cleaned of toxins and infections. Abusive living wears out organs. Heart and lungs age due to diets high in fat and insufficient exercise. The same goes for other body organs. Organs can be replaced either by transplants or by artificial organs. There are rejection problems to be overcome with transplants, but heart and cornea transplants are now commonplace. Prosthetic replacement for organs have developed slowly, but should benefit from the advances in the new biotechnology revolution. The Hayflick limit, until recently, put an absolute upper bound on how long we could live. Every living cell possesses a biological fuse that "burns down" a little every time the cell divides; in normal cell, each division brings death closer. The fuse runs out, and there is no more cell replacement in the body. The average cell can divide 60 or 100 times before this happens. The fuse on cancer cells never runs down, they are immortal. In 1993 Calvin Harley's team at Geron, a Californian biotechnology company have linked the biochemical changes that give cancer cells immortality to one that regulates ageing. They have already discovered a compund that makes cancer cells mortal in a test tube. They have found that cancer cells manufacture an enzyme called telomerase that rebuilds the cancer cell's fuse, so that the cell never gets the instruction to suicide. They have successfully made cancer cells mortal by inhibiting telomerase. This will lead to control of hayflick limit in healthy cells, allowing us to control their longevity without killing the organism with runaway cancerous replication. If, pessimistically, we can raise the human lifespan by only fifty percent in this generation, then that still means that you will probably live at least thirty years past the projected seventy-five years the insurance companies expect. With even a thirty year bonus, the leap into hundreds of years is likely to occur. If you are now 20 years old, you expect to die around 2045 AD. Add thirty years to that, and you live to 2075 AD. How many years will medical science be able to give you then? In 2075 AD, an increase of one hundred years would be conservative. So you can live on to 2175 AD. And where will life-extension sciences be by then? Likely any population problems will also have been solved.| Life extension technique | Maximum life-extension predicted | |
| Denckla death-hormone inhibitor | thirty years | 30 |
| Bjorksten cross-linkage dissolver | seven hundred years | 700 |
| Harman anti-oxidants | twenty years | 20 |
| Thymosin injection | uncertain | ? |
| "total body washout" | uncertain | ? |
| Prosthetics and transplants | uncertain | ? |
| Cell fuse extension | uncertain | ? |
| Grand total of extra years | 850+ |
About the author: Ian Woolf lives in Sydney, has a degree in Applied Science, worked as a solar astronomer, software engineer, systems programmer, webmaster, research assistant, Cisco CCNA tutor, Physics laboratory demonstrator, Computational Theory lecturer, and subject coordinator; while changing his career to freelance writing and broadcasting. Listen to Ian on the Diffusion radio science show on radio 2SER 107.3FM Monday at 6:30pm in Sydney or streaming audio on www.2ser.com, or listen to the Diffusion podcasts. You should follow me on twitter, here
Posted by iwoolf at March 21, 2004 3:51 PM | TrackBackComments
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