Human Life Expectancy - past, present, future

Wibbs

Originally Posted by DrIndy
The average life expectancy a couple thousand years ago was to reach your late twenties. Some countries now such as sweden have an average life expectancy of over 80 years.

That's a commonly held belief and I would suggest only partly true. life expectancy at birth figures don't take into account the higher infant mortality rates in earlier/primitive societies. This higher infant mortality rate conceals the substantial number of people who would have lived well into what we consider old age. Even the old "3 score and ten years" as the average for a man comes from a book written 2000 yrs ago. So 70 yr olds would have been considered normal back then.

Regarding technology in general, the knowledge base in medicine doubles every 3 years. We know twice as much about the human body and its myriad diseases every 3 years.

Great if that's true, but I frankly doubt it. If it was the case surely most of the diseases that kill us such as heart disease, stroke, cancers and neurological illnesses would have significantly better treatments and even cures by now. Now obviously, there have been leaps forward on the treatment front for many of aforementioned afflictions(childhood leukaemia for a start), but large scale "cures" for these diseases still elude us. HIV/AIDS is a good example. Billions of euros over nearly 30 yrs have been expended on finding a cure, yet we don't even have a vaccine ready yet. If the pace of change is so quick how is this possible?

Originally Posted by seamus
No Stress? Lol? You live in ramshackle housing, you have to hunt for food every day just to survive, the other males in the group are just as likely to kill and take your woman as help you, and your habitat is full of animals much bigger than you and capable of killing you. And you don't think that would be stressful?

Actually this is another fallacy, promoted by a hollywoodisation of our "cavemen" ancestors. Extant hunter gatherer societies live quite good lives. They have lower levels of measurable stress, lower incidence of mental illness, much lower incidence of dental caries, lower blood pressure, almost no type 2 diabetes and lower rates of heart disease.

Any doctor would tell you that getting regular exercise, eating a "natural" varied diet and close family/societal ties (even a healthy spirituality which studies have shown increase longevity. quick google http://www.sagecrossroads.net/Default.aspx?TabID=28&newsType=ArticleView&articleId=115 I'm not gonna live long then ). All factors found in hunter gatherer societies. In fact I read in an article in Nature some years ago that showed a drop in the lifespan of the Inuit after they were exposed to modern civilisation.


As for food gathering, recent research found that they have to devote less time acquiring food(especially in rain forest environments) than early isolated farming communities. It was only when large scale farming and the development of towns and cities did the food gathering workloads(for certain members of society) reduce.

On topic for a moment(not soon enuf says all ) If this proves workable it must be a boon for surgeons. Working on a living breathing human must be a nightmare. It must be like a mechanic trying to replace a gearbox while trying to keep the engine running.

An aunt of mine who was a doctor, used to joke that "surgeons know nothing and do everything, consultants know everything and do nothing and pathologists know everything, do everything, but it's 8hrs too late". Maybe with this they won't be too late in the future.

Capt'n Midnight

Wibbs wrote:

Even the old "3 score and ten years" as the average for a man comes from a book written 2000 yrs ago. So 70 yr olds would have been considered normal back then.
...
As for food gathering, recent research found that they have to devote less time acquiring food(especially in rain forest environments) than early isolated farming communities.

the 70 years is for people who die of old age, not accidents or disease which even then would have been thought of as premature deaths. Even taking infant mortality into account the figure of 70 as average seems like pure fantasy.

Even the bible agrees with the second bit, moving from a land of plenty to the sweat of your brow..

An important point is that for much of the western world life expectancy has peaked due to diet, exercise, etc. and is even going down.

An return to the land would be nice, but I've seen figures as low as 500,000 for the number of humans you could have in the US if you were to have little/no impact on the environment.

This technology could be used in Airports, flight delayed ? No problem, just step this way. 18hours to Oz, no problem. Also since you'd be relaxed your chances of injury during an accident would be less. Hey you wouldn't need seats either - you could stick twice as many people in a plane !

DrIndy

Great if that's true, but I frankly doubt it. If it was the case surely most of the diseases that kill us such as heart disease, stroke, cancers and neurological illnesses would have significantly better treatments and even cures by now. Now obviously, there have been leaps forward on the treatment front for many of aforementioned afflictions(childhood leukaemia for a start), but large scale "cures" for these diseases still elude us. HIV/AIDS is a good example. Billions of euros over nearly 30 yrs have been expended on finding a cure, yet we don't even have a vaccine ready yet. If the pace of change is so quick how is this possible?

No, it does, but not every single development results in a brand new class of drugs with groundbreaking new treatments. The knowledge base includes identying one more gene, identifying one more protein, understanding a little what each does, understanding how it interacts, recognising another rare disease process, developing a slightly better instrument etc..... Every now and then, there is an exponential development - which normally results in a nobel prize such as the identification of Nitrous Oxide as a signal to dilate blood vessels - and finally we realise who anti-angina drugs truly work and can develop new ones. The irony of that discovery is that Nobel invented dynamite - which uses nitroglycerine, which is a very potent vasodilator and used by people in their sprays.

In medicine, as soon as you treat one disease and eradicate it, then another comes along. Infectious disease have been significantly dented in the developed world and now heart disease and diabetes are common. Remove those and rarer disease become common. Its an uphill battle, but results in longer life as we delay death and treat better.

Thats the problem some people cannot understand as well about the health service, it literally is a black hole. If you were to double the budget, we would increase life expectancy significantly, add ten times the cash and we increase even further - there is no end as all it does is extend life further until eventually you hit the finite limit when nature/God decides time has come.

Wibbs

Capt'n Midnight wrote:

the 70 years is for people who die of old age, not accidents or disease which even then would have been thought of as premature deaths. Even taking infant mortality into account the figure of 70 as average seems like pure fantasy.

Apologies, I shouldn't have used the word average. What I meant to say was that 70 was not considered unusual. Even 80 seems not to be considered massively unusual as a lifespan.

http://www.phrases.org.uk/meanings/380400.html

Basically what I'm saying is the idea that all those years ago most people who reached adulthood were pegging it by 30 is a bit of a stretch. That said there was a good thread in After Hours a while back called "what would have killed you" and what came across was how many posters would have died in their youth if they hadn't access to medicine. It was a bit scary TBH. There were a few who posted saying they had made it to adulthood with very little help, but they were in the minority.

An important point is that for much of the western world life expectancy has peaked due to diet, exercise, etc. and is even going down.

I would say it's peaked more because of the massive reduction in childhood mortality rates, better hygiene(that has issues too of course, asthma etc) and control of infectious diseases through antibiotics. Some would argue our diet has gotten worse than some of our ancestors and our ancestors certainly got more exercise.

An return to the land would be nice, but I've seen figures as low as 500,000 for the number of humans you could have in the US if you were to have little/no impact on the environment.

No sorry, I wasn't being very clear again. I wasn't suggesting we return to some airy fairy utopia(sod that, like my telly too much), I was merely pointing out that our stone age ancestors had a better lifestyle than some give them credit for. After all we evolved to interact that way with our environment, so it stands to reason that lifestyle would probably be the "best" for us.

DrIndy wrote:

In medicine, as soon as you treat one disease and eradicate it, then another comes along. Infectious disease have been significantly dented in the developed world and now heart disease and diabetes are common. Remove those and rarer disease become common. Its an uphill battle, but results in longer life as we delay death and treat better.

Fair enough, but my point is that after all this time with huge resources thrown at them the things that killed us 30yrs ago(or more) are still the things that kill us today(at much the same age). In many ways the medicines have only served to assuage the symptoms rather than effect a cure, or prevent the disease forming in the first case. Now there are exceptions, that hormone blocking drug for the prevention and treatment of breast cancer(tamaxifen? SP) for a start. I was wondering are there other examples. Again I mention HIV. 20 + years of research and funding and we're no nearer a vaccine, much less a cure.

Thats the problem some people cannot understand as well about the health service, it literally is a black hole. If you were to double the budget, we would increase life expectancy significantly, add ten times the cash and we increase even further - there is no end as all it does is extend life further until eventually you hit the finite limit when nature/God decides time has come.

I doubt you would increase life expectancy significantly, as the causes of most of these diseases are based in lifestyle, genetics, simple old age and other factors beyond the remit of a health service(currently). The finite limit you speak of would likely be down to the length of an individuals telemeres, disposal of free radicals etc. The best you could hope for in most cases is a relief of the symptoms of old age. Which is a good thing.

DrIndy

Wibbs wrote:

Fair enough, but my point is that after all this time with huge resources thrown at them the things that killed us 30yrs ago(or more) are still the things that kill us today(at much the same age). In many ways the medicines have only served to assuage the symptoms rather than effect a cure, or prevent the disease forming in the first case. Now there are exceptions, that hormone blocking drug for the prevention and treatment of breast cancer(tamaxifen? SP) for a start. I was wondering are there other examples. Again I mention HIV. 20 + years of research and funding and we're no nearer a vaccine, much less a cure.

In fact, HIV CAN be cured - we now have HAART - Highly Active Anti-Retroviral Therapy. This involves a large selection of at least 5 different combination therapy for HIV to prevent mutations which would make it resistant to one single drug. People on HAART have a normal life, no viral load and otherwise well. HAART has not been proven that it results in normal lifespan but probably will when survivors last as long as everyone else. A vaccine is just over the horizon currently and there are several companies vying to be the first simply because they will make billions if they succeed.

30 years ago, people had some similar disease but a lot more TB and other infections. People with heart disease then do not come close to the life expectancy that people treated now would.

Some medicines do effect a cure and a fantastic one too. Look at modern antibiotics. Others delay and prevent, depends on the disease process.

Life expectancy has increased and people live longer and better lives.

I doubt you would increase life expectancy significantly, as the causes of most of these diseases are based in lifestyle, genetics, simple old age and other factors beyond the remit of a health service(currently). The finite limit you speak of would likely be down to the length of an individuals telemeres, disposal of free radicals etc. The best you could hope for in most cases is a relief of the symptoms of old age. Which is a good thing.

Yes we could, look at sweden where people live to over 80 years on average to ireland in its mid 70's. They have a much better funded health service! There will soon be treatments which will repair the damage of age too - why? Because there is so much money in it!

Panserborn

DrIndy wrote:

The knowledge base includes identying one more gene, identifying one more protein, understanding a little what each does, understanding how it interacts, recognising another rare disease process, developing a slightly better instrument etc.....

I work as a cell biologist and believe me when I say that the knowledge base as regard to protein interactions and the likes IS growing as fast as DrIndy says it is. If you miss out on papers for a week you can be left in the dark!

The problem is that for every protein interaction we prove, or gene product we discover, a miriad of further questions are created. It often happens that a protein whose function is thought to be well defined is thrown again into mystery by a single confirmed discovery. This happened to a protein called Chk1 - was thought to respond only to a single-strand DNA break but was recently shown also to be involved in the detection of a double strand breaks as well (this doesn't sound like a big deal but it is, large implications in chemotherapy).

Point is, we're learning how the mammalian cell works but this won't directly result in a useable therapy for quite some time - just because you know what a television does,doesn't mean you can repair it when it goes on the fritz during the soccer . A new aspect to newly funded cell research is something called "translational research", this wants medics and researchers to work more closely together to direct the useful information more efficiantly. Hopefully it will work!

Wibbs

DrIndy wrote:

In fact, HIV CAN be cured - we now have HAART - Highly Active Anti-Retroviral Therapy. / People on HAART have a normal life, no viral load and otherwise well. HAART has not been proven that it results in normal lifespan but probably will when survivors last as long as everyone else.

Fair point, but I would say that's more disease management rather than a "cure". Fair enough, it's certainly better than nothing by a long shot, but it doesn't eradicate the disease in the way an antibiotic helps to cure a bacterial infection. It's also expensive needing constant medical monitoring, making it largely unavailable to the 3rd world, where the problem is largest. As for living a normal life, the side effects of HAART therapies are hardly small, http://www.hivmedicine.com/textbook/haart/nw1.htm when up to half of patients switch therapies because of them. A cure is a long way off by that standard.

A vaccine is just over the horizon currently and there are several companies vying to be the first simply because they will make billions if they succeed.

We've heard this for years and every single attempt, while enlarging our knowledge base has singularly failed to offer protection against the virus. Here's just one older example. http://news.bbc.co.uk/2/hi/health/3399193.stm

Some medicines do effect a cure and a fantastic one too. Look at modern antibiotics. Others delay and prevent, depends on the disease process.

Well antibiotics are one of those exponential developments you spoke of before and have been around now for almost 60 yrs(in fact my oul fella was treated with them during WW2). I agree with you on improvements on the delaying front, but prevent? Any examples?

Yes we could, look at sweden where people live to over 80 years on average to ireland in its mid 70's. They have a much better funded health service! There will soon be treatments which will repair the damage of age too - why? Because there is so much money in it!

You could also look at a country like Greece, where the health service is less funded than ours and yet they still live longer than us. Okinowa is another example, where until recently the health service didn't compare to standards in the west, yet they're the longest lived people on earth. There are many other examples like that. In any event the Swedish longevity figures are just as likely to be due to their better funded health education and their traditionally better diet(higher fish intake etc). I don't deny for a moment that a better funded health service would make some improvements to lifespan, I would just suggest it would not be to the same degree as you suggest. Most medical authorities nowadays would push the mantra of prevention rather than cure, as most diseases(especially in the west) are based on lifestyle to a large extent(with genetic factors obviously).

As for repairing the damage of age, that's still quite a ways off too. The only proven way to increase lifespan in mammals is calorie restriction. http://www.infoaging.org/b-cal-home.html Now it's hardly practical for most people(and the jury's out as to if it'll work in humans at all, but it's likely). There is ongoing research to find drug therapies that will mimic the effects of such a diet, but even here we may be in for a wait as the mechanisms involved are still not fully understood.

Panserborn wrote:

Point is, we're learning how the mammalian cell works but this won't directly result in a useable therapy for quite some time - just because you know what a television does,doesn't mean you can repair it when it goes on the fritz during the soccer.

Panserborn, may I, as an amateur, respectfully suggest trying to gently thump a wayword cell on the side. It always seemed to work with the telly anyway.

simu

[mod] Split from this thread [/mod]

Panserborn

Panserborn, may I, as an amateur, respectfully suggest trying to gently thump a wayword cell on the side. It always seemed to work with the telly anyway.

Tried it, whacked them litterally by slamming the flask on the bench - they didn't like that, refused to grow for two days! Also tried a chemical whack with bleach when their time was up - they liked that even less!