Sunday, January 22, 2006

A Field Guide to Quackery and Pseudoscience – Part Three

Life Extension:

One of the constants of life, so we are told, is death. While there are people (and possibly other animals) who long for death, the studious avoidance of death is also fairly universal among living organisms. Enter the quacks and pseudoscientists.

The “field” of life extension has been around so long that its origins are lost in the mists of pre-history. For most of human history, life extension “techniques” were magical – as are most of those today. Then, starting in the late Seventeenth Century, science began to show us real ways to extend human lifespan. First with sanitation (e.g. clean drinking water) and then with a progressively more accurate understanding of how diseases occurred, we began to see a real improvement in human life expectancy. The average lifespan, which started at 30 years in the early 17th Century (primarily due to high infant mortality), is now up to the mid- to late 70’s in the Western world, with some countries pushing on into the early 80’s.

The problem with success is that once you achieve the impossible, it becomes part of your job description.

Not realizing the fundamental biological limitations of the human body, many people see the remarkable progress in longevity and expect that people will continue to live longer and longer lives as the technology improves. In truth, some people will live longer, but most won’t.

If you look at a survivorship curve of modern humans (see below), you will see a number of interesting points. One is that there are stages of life when mortality is relatively high. Early infancy is still a period of (relatively) high mortality, due (in the West) primarily to congenital disorders, although the growing reluctance to vaccinate children may change that. The next period of high mortality – especially for males – comes in the late teens and early twenties. Anyone who has lived through that period of life should understand why this is so.

After passing through the twenties, the mortality rates remain relatively stable (deaths due to trauma decrease, deaths due to disease increase) until (in 2002) about age 45, when the mortality rate begins to accelerate. In the 2002 figures, this curve continues to grow steeper until about age 100, when it flattens out. However, at this point, the percent surviving is about zero. About, but not quite.

It is these few, these happy (we hope) few, that capture the attention of those who are interested in living longer. In its November 2005 edition, National Geographic interviewed a number of healthy elderly people in a vain attempt to find out their “secret” for a long, healthy life. I call this a vain attempt because, like so many people before them, the editors of National Geographic are looking at the wrong people. Instead of looking at the people who are living longer, we should be looking at those who aren’t.

From the 10 November 2004 issue of the National Vital Statistics Reports:

“Life expectancy was 74.5 years for males [in 2002], increasing by 0.1 year from 74.4 years in 2001. Life expectancy for females in 2002 was 79.9 years, increasing by 0.1 year from 79.8 years in 2001. The increase in life expectancy between 2001 and 2002 for females was primarily the result of decreases in mortality from heart disease, cancer, homicide, cerebrovascular disease, and chronic lower respiratory disease. The increase in life expectancy could have been greater if not for the offsetting effect of increases in mortality from accidents, Alzheimer’s disease, pneumonia, perinatal conditions and septicemia. For males, life expectancy increased primarily because of decreases in mortality from heart disease, homicide, cancer, cerebrovascular disease, and HIV disease. The increase in life expectancy for males could have been greater were it not for the offsetting increases in mortality from accidents, diabetes, septicemia, perinatal conditions and Alzheimer’s disease.” [italics mine]

So, despite the doom and gloom from various “alternative” medicine promoters, life expectancy in the United States, at least, continues to increase despite our lack of attention to them. Interestingly, despite much ballyhooing of increasing cancer deaths, cancer doesn’t seem to have had an impact on longevity. In fact, the report specifically mentions that cancer mortality is decreasing.

And what were the factors holding back even greater increases in longevity for both men and women?

[1] Accidents
[2] Perinatal conditions (a vague term encompassing deaths in early infancy)
[3] Alzheimer’s disease
[4] Septicemia

None of the currently popular nostrums or programs for life extension address either accidents or perinatal conditions (since most, if not all, are aimed at aging Baby Boomers who have – by definition – successfully avoided “perinatal conditions”). Septicemia is addressed, at best tangentially, by those remedies that promise to “enhance the immune system”, although that may also have the effect of increasing mortality from autoimmune disorders.

Alzheimer’s disease, the new horror of the Baby Boomers, is prominently mentioned in several life extension programmes, but no real data is offered to support their claims. Considering that it may take decades for Alzheimer’s disease to fully manifest, it is a safe promise to make. Besides, how many people (or their families) would bother to ask for their money back if they did develop Alzheimer’s disease?

Nutritional “supplements”, crystals, meditation, “antioxidants”, hyperbaric oxygen, the list goes on. The details of the “treatment” are myriad, as are the ways in which these “secrets” of life extension were discovered. Two features are consistent, however:

[1] The purveyors of these “treatments” continue to age at a normal rate.
[2] None of these “treatments” have been shown to work.

Since it would take decades to show if the “treatments” worked, the purveyors will have a long time to spend their proceeds before a customer (or their surviving relatives) comes to collect a refund.

A closer look at the survivorship curve (see below) shows the fundamental problem. Comparing curves from 1900 to 2002, you can see that improvements in medicine and sanitation have significantly reduced mortality in early and middle life. However, in the 1900 curve, the proportion of people living to 100 years was only slightly less than there are today. The difference is in the number of people living to 80, 90 and even 95 years, which is significantly different between 1900 and 2002.

This would suggest that there is a longevity “wall” somewhere around 100 years. Biology tells us that there may be many reasons for this – telomere shortening being one of them. Certain tissues have a “pre-programmed” limit on the number of cell divisions they can undergo, after which they die from loss of genetic material. These tissues do not normally divide rapidly, so this may function as a “fail-safe”, preventing uncontrolled cell division – or cancer.

So, are any of the longevity “secrets” likely to work? No. People have been trying to find the “secret” to longer life for all of recorded history, and none have found it yet. Even careful examination of people who have lived over 100 years fails to reveal any consistent “secret” except one:

Have long-lived parents.

I can’t see how anyone can change that.


Coming up: Psychics


Anonymous Anonymous said...

Thanks Prometheus,
Another great chapter to the most useful field guide.

Funny that we never read testimonials from the longevity impaired. Are life extentionists trying to hide something?

If you'll excuse me now I have to go try out my new patented telomere lengthening enhancement device.

I'm also going to make sure my parents are kept on life support indefinitely, if need be. Thanks for the tip ;-)

25 January, 2006 05:32  
Blogger Bartholomew Cubbins said...

I always wonder if people so afraid of death haven't also duped themselves into believing they'll be a Connor MacLeod, minus the sword thing.

26 January, 2006 04:20  
Blogger clone3g said...

There can be only one Highlander

26 January, 2006 06:03  
Blogger Bartholomew Cubbins said...

Clone3g - you had me on pins and needles, I was worried that the link would send me to a Griers video or some other pr0n.

26 January, 2006 13:36  
Anonymous Anonymous said...

Thank you for saying this. It really annoys me to hear people tell me that if I just do X, Y or Z, I'd live longer. I keep wanting to ask them "how much longer?" I've had three of my grandparents survive past the age of ninety (both my grandmothers and a grandfather). One of my grandmothers started going senile at about age sixty; the other is currently drifting off into the world of senescence (aged 94). My grandfather was on constant oxygen in his last few months of life, because he had chronic emphysema (despite his not being a smoker). With that kind of family history in front of me, I'm looking at living at least until retirement age (65) without any real decrease in quality of life, and possibly well into my eighties (which means I *definitely* don't have enough superannuation). Then again, I could fall in front of a bus tomorrow.

It's like the old joke says - giving up smoking, drinking, sex, fatty food, sugar, and sitting in front of the TV laughing may not make you live longer, but it'll sure seem like it. I figure I'd rather go like my other grandfather - suddenly, of a heart attack, at about the age of seventy.

27 January, 2006 00:30  
Blogger Prometheus said...

Anonymous brings up a good point - that quality of life is as important as quantity. And having to gulp pills, drink "nutrition" shakes, balance your essential oils, etc. from age fifty to whenever does not sound like a quality life.

On top of that, there is no reason to think that any of it works - no data so far.

In my family, my grandparents all lived past 90 years, with one grandmother living past 100. It wasn't diet: they all ate red meat like whenever they could, drank in moderation - except for coffee, which they were all most immoderate about - and got as little exercise as was compatible with making a living.

Even my alcoholic great uncle lived to 90.

There are certainly things that you can do to reduce your chance of dying "early", like watching your weight, getting some exercise and wearing your seatbelt. And there are even things you should do to prevent (or at least delay) the consequences of your choice of parents (have your blood pressure checked regularly, etc.).

However, the biggest impact on your lifespan (other than certain lifestyle choices) is the one thing you can't change - your genetics.


27 January, 2006 17:37  
Blogger Bronze Dog said...

Saw that special on the first emperor of China.

"Mercury can help... a lot."

Of course, we know he was referring to Hg+, and not thimerasol, like Fore Sam is fond of confusing.

31 January, 2006 15:27  
Anonymous Anonymous said...

Whilst what you say about the infestation of quakery in "longevity science" is very true, the same could be said for medicine itself in the turn of the last century. Meanwhile, science continues to advance and illuminate the mysteries behind the mechanisms and evolutionary purpose of aging. We have more reason to be optimistic than ever before of imminent legitimate interventions that will seek to treat aging as a disease rather than an incurable inevitability. The signs have been there since the first cell cultures were able to be immortalised with very little intervention - sometimes spontaneously. There is a huge chasm, of course, between cell lines and highly complex multi-cellular organisms. The sobering question is, will we be one first generations to cross the bridge being presently built or will we be one of the last left behind?

The other "Prometheus"
from the Immortality Institute.

07 May, 2006 02:52  
Blogger Einzige said...

The "wall" you speak of, Prometheus, (also know as maximum life span) is pretty well established at roughly 120 years.

It's very true that there is little real science in this area of medicine. What progress has been made has basically been in the area of discovering how little we actually know. In other words, in the past we didn't know what we didn't know, whereas today we know more of what we don't know, but we still can't be sure how much more there is of stuff that we don't know we don't know... You get the idea.

A big part of the problem is that scientists are still not sure what aging actually is. Without knowing what it is, you can't design any metrics for it, so you can't know for sure whether or not a given treatment is having any effect on it! One possible way around this is massive-scale longitudinal studies of humans, but I'm sure you can already picture the logistical and ethical implications of such, and, anyway, none of us would be the beneficiaries of the results (assuming, optimistically, that anything fruitful came out of the results).

Bottom line: don't believe the hype.

22 June, 2006 15:57  

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