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Reddit user explains aging vs cancer (reddit.com)
202 points by ericmsimons on Sept 10, 2011 | hide | past | web | favorite | 35 comments

Just to be finicky, cancer is not in fact worthy of being called the "inevitable killer of mammals," through might be accurate in calling it the inevitable killer of mice, as said beasts are little cancer factories.

In humans, supercentenarians (110+) don't tend to die of cancer - in fact your odds of dying from cancer appear to decline precipitously past the 80s and 90s. I'd wager we won't know definitively why this is the case before there are good general cancer therapies in circulation, though.

The condition that presently acts as a final full stop to catch everyone lucky enough to miss out on all of the other fun little fatal surprises at the decaying end of life is called senile cardiac TTR amyloidosis. Some description:


The short of it is "gunk clogs the tubes" but the long of it is much more involved - and like many things found in aging it has a rare youthful variant probably caused by unlucky genes. I note that the SENS Foundation puts some funding towards work on the narrow range of promising therapies for this condition:


I read Long For This World and both gunk and cancer were on Aubrey De Grey's list of 7 Deadly Killers (or whatever it was). The impression I came away with from that book was gunk was a plausible target for future technological remedy but cancer presented a much more difficult problem (for reasons explained in the book.)

The careful qualifications to your case above seem to catch this objection, but based on my reading that book, I would gather that supercenternarians dying of gunk not cancer aren't necessarily immune from cancer. They may just be lucky in that gunk, at this period in history, got to them first.

If it isn't luck but something else, there's also the problem of extrapolating a therapy from that. De Vere's solution to cancer was replacing every cell in the body every 7 or 8 years to circumvent the effects of telemerase ( or something like that, I'm not a gerontologist obviously.) It would be interesting if these supercenternarians's bodies were doing something like this, but it would be more interesting if it led to a more practical therapy.

Thank you for linking to this interesting discussion on Reddit. Their discussion lacks a few key points.

First, inflammation is an important cause of cellular (and DNA) damage. The standard weapon used by your innate immune system is super-oxide, a free radical! Avoiding chronic infections is likely to be an important key to longevity, especially for those prone to inflammation.

Second, while "aging" is a natural mechanism by which your body defends against cancer, "aging" quickly is not the ideal way to prevent cancer.

Your cells will stop dividing when they have reached their Hayflick limit. This limit is not exactly caused by telomeres, but rather the lack of telomerase (a protein that lengthens telomeres). Active telomerase is necessary for a cell to become cancerous.

So the cell has its own built in mechanism to determine when it has divided too many times, as well as when it has accumulated DNA damage from external sources like UV or oxides. Your cells have "aged" when they have accumulated too much DNA damage! So aging, in this sense, is not a good way to prevent cancer. The aged body is filled with tumors that are near metastasis, and undergoes drastic changes (eg. reduction in hormones) to prevent cancer formation.

The only real way to prevent cancer is to stop cell division. This, of course, is not ideal. How would we grow to become an adult without cell division? How would we heal damaged tissue? The answer is actually in the growth pathways of mammals.

It turns out that dwarfs (little people) have very low cancer rates. See for example: http://www.scientificamerican.com/article.cfm?id=defective-g...

These people lack a gene (in a pathway) that is necessary for cancer to form. Knocking out genes in growth pathways in mice drastically reduces their cancer rates (the mice are also small). Want to prevent cancer? Stop growing!

This is completely unrealistic, of course. However, populations with limited activity in their growth pathways will be less prone to cancer. This extends to short people too, not just dwarfs.

Wouldn't dwarfs have less cancer simply because they have fewer cells that can become cancerous?

Those dwarfs seem to get even less cancer than you would expect given the reduced number of cells.

Also, on a related note, there's Peto's Paradox about why cancer rates are similar across species despite vastly different sizes (mice, humans, whales).


Paper behind paywall: http://www.sciencedirect.com/science/article/pii/S0169534711...

Dwarfs suffer a number of other related health issues.

If this idea is true, people who appear/feel younger in their old age should be more prone to get cancer. A testable proposition.

Or maybe those who look younger haven't needed the protection of aging because they've accumulated much less DNA damage in their lifetime (because of low sugar diet, slow basal metabolic rate, etc.), and less DNA damage = lower incidence of cancer.

Asian Pacific Islanders (API) (who appear younger than they are in general, in my opinion) have the lowest incidence rates of cancer out of all races (for adults).


My understanding is that we all have cancer cells in our body — the problem becomes when they get triggered. There may be something in the immune system that has something to do with this. What depresses me with this subject is that it seems like the more we know about it the more we understand how much more we really need to learn. Also as I get older I keep coming across more members of my peer group (and people I know who are older) who get some form of cancer. It seems like we've made some progress in my lifetime, but it's too slow for my tastes. In my dream of dreams someone would come up with a silver bullet.

We all have tumors in our bodies, not cancer. Cancer is when the tumor metastasizes, and begins to grow out of control.

Perhaps instead of hoping for a silver bullet to cure cancer, determine when/if your body is full of tumors, and do everything you can to prevent them from accumulating any more DNA damage.

I think one of us may be confused about the definition of metastasis. From (http://www.merriam-webster.com/dictionary/metastasis) it appears that metastasis typically happens after a cancerous tumor has been around for a while, when some cancerous cells escape the tumor and start dividing elsewhere.

One of the things he mentions is to not stress. How do you do this? I'm not a worry wart or anything, but sometimes it seems like I can't help my body's natural response to certain situations.

I think he means to just try to avoid stress. The way I do this is--

A) Avoid situations which I know will be stressful. Not all situations that are stressful are harmful in the long run, though. For me, meeting people is stressful, but it pays itself off as if you're lucky enough to come off as likable you may have new friends, which will reduce your stress. People who socialize have been shown to live longer and be happier, according to Richard Restak in his book "Think Smart."

B) If you're troubled by something stressful (which has already occurred), I find it best to locate the exact thing that is stressing you and why it's stressing you. If it's an exam coming up, I try talking it over with people and venting. This has helped me a lot. I'll recant Think Smart again, where Dr. Restak recommends asking yourself these questions:

"Am I going to allow this experience to determine the course of the rest of my life? Or am I going to take control of my life? What can I learn from this experience?"

He goes on to say:

"Mentally reformulating things in this way will increase your feeling of control and protect your brain from stress-induced damage. This is important, since loss of a sense of control is the main contributor to the stress response. No matter how stressful the situation, if you retain control of your attitudes and responses this along will lessen your stress--even if you can't affect the situation responsible for the stress."

Couple quotes:

"Not being able to govern events, I govern myself." -Michel de Montaigne (useful for stressful situations)

"If you are distressed by anything external, the pain is not due to the thing itself, but to your estimate of it. This you have the power to revoke." -Marcus Aurelius (had to remind myself of this today)

Hope this helps.

For a nice read about stress and the body's stress mechanisms you should have a look at Why Zebra's Don't Get Ulcers by Robert Sapolsky.

The book is more about the effects of stress than how to avoid it, but the author suggests:

1 - Exercise (pick something you enjoy, preferably aerobic) 2 - Meditation (seems to help while you're doing it, less clear on persistence of effects) 3 - Control - it's nice if you have (and feel) some control in your life. 4 - Have a system of social support. 5 - Religion and spirituality. Very loose ground here. 6 - Cognitive flexibility (different coping strategies for different stressors)

Personally, I've found that regular exercise is a big stress reducer. Particularly heart rate interval training, alternating periods of over 90% max heart rate with recovery periods below 70% max heart rate.

A lot of the problem isn't so much the stress in particular, as it is your endocrine system's response to it. You go into fight or flight mode and start pumping out cortisol, and most of the rest of your system goes into standby.

Serious research into it is pretty young, but things like regular exercise can help control the process a bit more. We're starting to find compounds that can reduce cortisol response as well (eg. a couple of cups of black tea a day seems to noticeably reduce it.) As research progresses, we should see more advancement.

In the meantime, most of the 'good for you' stuff tends to reduce the problem. Eat well, exercise, get enough sleep, and so forth. They all work to minimize your body's response to stress. Avoiding stressful situations is ideal, but they aren't the root of the problem as much as cortisol is.


I subscribe to the Disposable Soma theory of aging. http://medicine.jrank.org/pages/1758/Theories-Biological-Agi... [1]

In this scheme cancer is just one example of the balance between somatic maintenance and reproduction rate.

[1] The disposable soma theory of aging predicts that species and cohorts in a population expecting, on average, to have high survival and low reproductive rates should invest more heavily in protecting their somas than species and populations that expect a short lifespan and to reproduce rapidly

Any discussion on cancer is very incomplete without an acknowledgement that pre-civilization cancer was much more rare, and in some hunter-gatherer societies almost unknown. Good Calories Bad Calories has a good discussion of this and other health issues in some remote areas. Some members of those societies lived into old age, and some members of our society get cancer at young ages. Along these lines, I would be very interested in reading about cancer rates of animals in natural environments. One must assume that the talk of mice getting cancer is referring to lab mice.

In pre-civilization, how would they have known that someone had cancer?

A better question (and maybe the one you are asking) is how would we know if someone outside of civilisation actually had cancer. You have to draw on various sources of evidence. It is possible to see evidence of health issues in skeletons, the most obvious example pertinent to this discussion might be something like bone cancer. The most convincing evidence on the issue is observational. It comes from people from civilization documenting populations that are hunter-gatherers or pastoralist and sometimes partly subsistence agriculturalists. As mentioned, there is a discussion of this type of evidence in GCBC by Gary Taubes. Doctors from civilisation would go to the frontier, deal with disease in the frontier populations, and note an extraordinary lack of disease in the native populations. The best documented groups are various groups in Africa, the Inuit, and some Pacific islanders like the Kitavans. Finding a case of cancer in an Inuit was worthy of publication in a journal. In the case of the Kitavans a researcher actually went there specifically to study their health. There was not a single overweight individual that had lived on the island their whole life. There were (a few) ~100 year old individuals without any sign of disease. They could recount the one time in their populations recent history that it appeared that someone from the island had cancer. People there (that don't die from accidents) presumably die from infections, not from cancer and other degenerative diseases.

That's really interesting, thanks for sharing that. I always assumed that before modern medicine identified cancer, people thought that they were dying of other diseases & what not when in reality they had cancer. Is there any way that scientists can figure out if people from centuries ago died from cancer (excluding bone cancer)?

It is all a very vague science to try to look back in time. Centuries is not that long ago, and one can try to assume that remote indigenous populations are still similar. Lets assume we are talking thousands if not tens of thousands of years ago. There are a lot of things that scientists can try to interpret from skeletal and other bone remains, only some of them that would be a direct link to cancer. This is a good overview of some of the science that goes on for that in a context that is relevant to the discussion at hand: http://wholehealthsource.blogspot.com/2009/03/paleopathology...

Personally I am convinced that cancer is just one of many degenerative health issues. If you follow that line of reasoning, than the frequency of degenerative issues in skeletal remains are likely related to the frequency of cancer and any other degenerative health issue. As one example, if you simply see caries (cavities) in the remains of the teeth, that would also mean cancer was more likely to occur. (very healthy indigenous cultures have almost no cavities). Obviously this is very loose logic, and certain groups are more likely to have certain issues that are more or less likely to show up in skeletal remains, but I believe the general principle is sound.

We can inspect the skeletons and determine if there was cancer present. I have also read that it was largely non-existent in paleolithic cultures, indicating agricultural products and lifestyle, but I'd like to see further confirmation of this.

So the natural question is - what can one practically do to try to postpone DNA damage as much as possible?

The only treatment that has large proven effects is calorie restriction[0] although that really lowers ones quality of life. Intermittent Fasting [1] seems to have many of the same benefits without being anywhere near as hellish.



3rd paragraph: "If you have a healthy diet low in sugar, high in antioxidants, in theory you can reduce DNA damage, keeping your DNA looking younger", etc...

Eat your leafy greens.

With respect to antioxidants, there had been mounting evidence recently that antioxidants could paradoxically increase cancer risk. The evidence so far is that there are cellular pathways that spool up in the presence of oxidants and can cause cells to undergo cell death. Antioxidants can hinder these pathways from firing and instead, allow cells to linger around longer than they should.

Slip-slop-slap (http://en.wikipedia.org/wiki/Slip-Slop-Slap), or just stay out of the sun as much a possible (do not stay in a bunker 24/7, as that would lead to vitamin D deficiency)

That is nice explanation. As our ancestors used to say - Clarity is an evidence. ^_^

There is another simple point - who on earth will ever publish a study which proves that the whole ready food and fast food industry makes us sick, that the whole idea of office work (and driving a car!) is deeply wrong and that just vegetarian diet and regular exercise, e.g. agriculture work, and community of our equals is what we need because it defines what we are? ^_^

Of course, the study that shows that common sense has some sense will never be widely pushed through media. First, who will give you money to prove things that everyone knew but forgot? And corporations, who need to push more crap to get more profit, will stop it on very early stage, because that is the best strategy for them.

So, yes, diet, exercise and proper state of the mind (avoidance of stress, attachments, passions) together makes us healthy and younger, but people knew this for aeons without any Wikipedia articles. ^_^

It sounds like we have enough information in understanding the problems of aging and cancer that we're at a point where solving these problems is possible.

I keep thinking something I heard in a yoga class: "The pain that is to come is to be avoided."

Unfair title--the redditor himself says that while his hypothesis is scientific and has some cellular evidence, it is still a more or less unproven principle.

Fair point - I would edit it, but it's locked down now. I didn't intend to mislead HN readers with this title.

Additional ideas to consider:

1. Human stem cells will reproduce indefinitely without aging in a controlled environment.

2. Some turtles live 200 years, do they have a different DNA aging and cancer management program?

3. I thought aging was due to the polymerase having run out of buffer telomere junk data, cuts into the in-use data DNA files that are responsible for managing the refreshing of your body. src http://www.hhmi.org/biointeractive/cancer/animations.html

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