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alebar14

macrumors regular
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Jul 14, 2007
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Auckland CBD, New Zealand
There is now a way to extend the lifespan of organisms so that humans could conceivably live to be 800 years old. In an amazing development, scientists at the University of Southern California have announced that they've extended the lifespan of yeast bacteria tenfold -- and the recipe they used to do it might easily translate into humans. It involves tinkering with two genes, and cutting down your calorie intake. Tests have already started on people in Ecuador.

According to an announcement from PLoS Genetics:

Researchers have created baker's yeast capable of living to 800 in yeast years without apparent side effects. The basic but important discovery, achieved through a combination of dietary and genetic changes, brings scientists closer to controlling the survival and health of the unit of all living systems: the cell. "We're setting the foundation for reprogramming healthy life," says study leader Valter Longo of the University of Southern California.

Longo's group put baker's yeast on a calorie-restricted diet and knocked out two genes - RAS2 and SCH9 - that promote aging in yeast and cancer in humans.

"We got a 10-fold life span extension that is, I think, the longest one that has ever been achieved in any organism," Longo says. Normal yeast organisms live about a week.

"I would say 10-fold is pretty significant," says Anna McCormick, chief of the genetics and cell biology branch at the National Institute on Aging (NIA) and Longo's program officer. The NIA funds such research in the hope of extending healthy life span in humans through the development of drugs that mimic the life-prolonging techniques used by Longo and others, McCormick adds.

Baker's yeast is one of the most studied and best understood organisms at the molecular and genetic level. Remarkably, in light of its simplicity, yeast has led to the discovery of some of the most important genes and pathways regulating aging and disease in mice and other mammals.

Longo's group next plans to further investigate life span extension in mice. The group is already studying a human population in Ecuador with mutations analogous to those described in yeast.

"People with two copies of the mutations have very small stature and other defects," Longo says. "We are now identifying the relatives with only one copy of the mutation, who are apparently normal. We hope that they will show a reduced incidence of diseases and an extended life span."

Longo cautions that, as in the Ecuador case, longevity mutations tend to come with severe growth deficits and other health problems. Finding drugs to extend the human life span without side effects will not be easy.

I've always been a skeptic when it comes to life-extending research, but this has me rethinking my position.

SOURCE: http://io9.com/345728/geneticists-discover-a-way-to-extend-lifespans-to-800-years
 

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It's a bit of a leap from "we can extend the life of a single cell" 10 times to "we can extend the life of a human, composed of billions of interacting cells of different natures 10 times".

That being said, I don't know if I'd want to live 800 years or not. Initially it seems like it could be a good thing - seeing tremendous advances in technology, etc.. But unless we significantly reduced birth rates or inhabited other planets, we'd live ourselves out of space here. Assuming we didn't kill ourselves first.

Are older people more enlightened?
 
It's a bit of a leap from "we can extend the life of a single cell" 10 times to "we can extend the life of a human, composed of billions of interacting cells of different natures 10 times".

Yeah, exactly. A few things come to mind in a highly complex multicellular organism like ourselves.

First: Organ failure, we're only as long-lived as our weakest part.
Second: Cancer, billions of times as many cells times 10 times as long a life equals much higher risk of dysregulated cell division and neoplasia. Just knocking out Ras2 and SCH9 is not going to be sufficient to prevent sporadic mutations in p53, Rb, or a host of other genes whose mutants can cause cancer.
Third: Neurodegeneration, which seems to have a heavy environmental component, would be quite common. Similar to point one, but does not require full out failure of the organ. Interestingly, the prevalence of dementia in the 80+ demographic is quite high, I believe well over 50%.
Fourth: Metabolic pathways in humans or multicellular and multi-systemic, meaning that the nature and effects of caloric restriction are quite different in yeast and humans. To whatever extent fundamental biochemical pathways are conserved, storage processes certainly are evolutionary developments that occurred after the yeast, not before.
Fifth: Since when could we knock out a gene in a person? No good way to do this yet, even if the above were not true.

The problem with the popular press is that it promotes a distortion of what science means. I haven't yet read this study, but it probably just shows that Ras and SCH9 are involved in the aging process (and I'll agree that that general process may exhibit a relatively high extent of conservation from yeast to mammals), and that diet has an impact as well.

But to scale these claims to anything approaching a suggestion about increasing human longevity is apocryphal.

Addendum: Caloric restriction probably is good for you, though. I'm a little more wary of getting rid of a Ras; seems like that could have unintended signaling consequences over the long term. And one final point: remember that scaling here is probably non-linear. The yeast's lifespan can be extended many more times not simply because it is less complex, but also because its absolute lifespan is shorter. Multiplying 80 years by 10 is a much greater feat than multiplying how many ever days or weeks a yeast cell lives by 10.
 
The rule is if you get the gene therapy (?) (which has never been successful in humans) then you have to become sterile.

This won't be able to happen any time soon. Call me back when we can successfully change DNA in a full grown organism with billions of cells.
 
What if the net result was an added 30 years in humans? How many would be inclined then?
 
Dark thought moment...

... what if this happens and as you grow older you forget relationships who have passed on in other ways.

Imagine the partner you have now, or one that you would spend the rest of your life with. You both can live to 800 but one of you dies after 30 years.

Ok I'm off to watch happy comedy. :eek:
 
Yeah. Who wants to live for 800 years if the rate of aging is still the same as today? Who wants to end up a prune by age 80, and then extend that prune-ness for another 720 years? I'd rather be dead, thanks.

That's the question... and if the aging process is slowed, would you really want to spend 10x longer in the decline from 60-90?

This would be really cool if 2 things could be accomplished:

1. It can be used intermittently throughout ones life, so you could extend the time between say 18-50 10x but then progress normally from there so as not to offer a painfully extended stint into the bodily decline. What good is living 10x longer if arthritis and senility keep me from doing the things I enjoy.

2. It would still only require about 40-50 years of work in order to ensure a comfortable retirement. The only way I'd really like to extend out my current years by 10x is if I can still manage to retire at a moderately decent age, effectively increasing my relaxation years by a factor of 10x.

The big potential problems exist in the population explosion from old people not dying, but if aging is slowed there's the potential for many more fertile years for young people which could also increase the number of offspring couples have. My wife and I would probably have a lot more kids if we could space them out 10 years or so, but having more than 2 in a 8-10 year span seems to be overwhelming, and the physical decline/age we'll be when they get older limits us to a certain age range which will probably keep us at 2, maybe 3 kids.
 
Yeah. Who wants to live for 800 years if the rate of aging is still the same as today? Who wants to end up a prune by age 80, and then extend that prune-ness for another 720 years? I'd rather be dead, thanks.

Who indeed…
Nam Sibyllam quidem Cumis ego ipse oculis meis vidi in ampulla pendere, et cum illi pueri dicerent: Σιβυλλα, Τι θελεις; respondebat illa: αποθανειν θελω...

Don't forget the eternal youth gene as well…
 
... what if this happens and as you grow older you forget relationships who have passed on in other ways.
I think if humans were truly to live for hundreds of years (which I doubt is anytime soon in coming), the concept of relationships, or specifically a "til death do us part" monogamous marriage would become obsolete.
 
Degeneration

What many people don't realize is that the decline of humans in old age may be unnecessary. There are people who live a lively, happy, active life until they die. The modern diet of sugars, processed foods and chemicals causes many of the debilitations of age (exacerbated by stress and lack of exercise). Modern diseases such as adult-onset diabetes, heart disease, and cancer were not common in older people like they are today. Our modern technology keeps older people alive, but our modern diet and lifestyle makes them weak and debilitated. Maybe our diets and lifestyle will change, or maybe technology will eventually overcome it all.

There is no obvious reason that people need to decline or age at all. Cells can and do rebuild themselves (otherwise, how would we create a new baby human from two people in their teens, 20's, 30's, 40's and sometimes even 50's?). Scientists recently built a new beating mouse heart almost from scratch. In 10 years, maybe they will be able to recreate human organs so that a person with heart disease (modern diet) will be able to receive a new heart created from his old heart. Remember that 40 years ago, no one had ever even had a heart transplant.

A little over 200 years ago, the only transportation was via horse. There were no cars or even trains. Just horses. There were no phones. There was no electricity. At night, people used candles for light. Doctors used the same techniques regardless of the disease. There were no published books of medicines! The average lifespan was 35 years old.

I doubt those people without lights, phones, or motorized transport ever imagined that the average lifespan could ever be 80 years old! I suppose it's only natural that we can't imagine the future either.
 
I think that it would be really wrong to extend people's life spans. Think about the younger generations. How can we justify the over population that would come from this?
 
I think that it would be really wrong to extend people's life spans. Think about the younger generations. How can we justify the over population that would come from this?

Yeah, I can hear all the 400 year-olds whining about how the older generation just doesn't "get" them.

And all the 800-year olds reminiscing "When I was young, we, uh.... Wait, what the **** did we do?"
 
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