As we age, cancer rates go up as immune system winds down
arstechnica.com
arstechnica.com
[i] http://www.slate.com/articles/health_and_science/medical_exa...
They try to reconcile the studies: maybe it's the natural-ingredient foods vs the refined foods, maybe it's the generous diet vs the more-than-generous free-feeding, or conceding that the monkey's don't live longer, but they live healthier.
IMO, the best paragraph from the article was this: "Many of us simply roll our eyes and click away when yet another medical study contradicts the last study—so what else is new? Coffee’s bad for you, until it’s good for you—and so is red wine. Antioxidants are essential, or they’re useless. And so on."
Other than some very basic common sense things -- like don't eat rat poison -- I never find that these kinds of studies lead to correct and actionable information about how to slow down aging or how to lead your life. And it's extremely frustrating to even try.
Sorry, I should have been clearer. I meant, to even try to keep up with the contradictory medical studies.
Yes, you should exercise; that's a common sense thing I'm referring to. But trying to decide if things like calorie restriction really work in the face of conflicting studies is frustrating.
spoiler alert - the comprehensive review lead them to the conclusion to eat plants, unprocessed.
But anyway, it is a nice resource to get a round up of studies on a similar topic.
If you cherry-pick different studies you might actually find that consuming large amount of plants stresses our digestive system way more than a fatty steak with potatoes.
You really, REALLY, believe with all information being out there nowadays that a diet of only "fatty steak with potatoes" will be healthier for humans that the "balanced WFPB diet" that is nutritionfacts.org claims is scientifically proven to be the healthiest?
I think you have nothing to back that up. Please cherry pick how you please and present your evidence.
Dr Greger, who started the non-profit nutritionfacts.org, is often attacked for being an ethical vegan. Since people reason that would impair his ability to present unbiased evidence. Though no-one has ever gotten beyond claiming he's cherry picking. I wish someone would describe a different diet that is as well supported by scientific evidence, as what nutritionfacts is doing for WFPB.
There is some scientific evidence building up in for the Keto diet. But that is --as far as I know-- not a diet for life.
On the other hand there is the raw diet movement (basically an uncooked WFPB diet), but that has little scientific and mostly anecdotal evidence.
The raw diet is mostly a trendy thing people write about. The bioavailability of nutrients in many raw foods is just too meh.
We know what the best diet is. A plant and fish based diet with small amounts of other meat. Meat that doesn't subsist on a diet primarily of corn or other, less edible things. This diet is completely unsustainable on a global scale and would result in even more ecological havoc.
The discussion between plants or plants + meat is complicated, but for now I'm going to ignore it because there's more important considerations:
- Companies are making our produce harder to digest as they try and make products with a longer shelf life.
- Eating industrially produced meat (of any sort) is very unhealthy and in many ways unsafe.
- This entire discussion removes dairy from the equation, which is a large part of the puzzle for most people.
- The low-carb vegan and the low-carb omnivore are far better off than anyone consuming 200g+ of carbohydrates a day.
- Hydroponically grown carrots taste gross.
Nope. Fish (most fish) as a central part of diet, will contribute a lot to build up of heavy metals in humans. And what is "small amounts of other meat"? 3x per week? This is basically an omnivorous diet. Compared to the SAD is probably just the junk cut out.
This, SAD-processed, is a very unhealthy diet, compared to a balanced WFPB diet. There are lots of studies to back this up.
> - Companies are making our produce harder to digest as they try and make products with a longer shelf life.
Yups.
> - Eating industrially produced meat (of any sort) is very unhealthy and in many ways unsafe.
Not a problem for those eating WFPB.
> - This entire discussion removes dairy from the equation, which is a large part of the puzzle for most people.
Dairy is a killer. Prolly more so than meat.
https://www.youtube.com/watch?v=h3c_D0s391Q
> - The low-carb vegan and the low-carb omnivore are far better off than anyone consuming 200g+ of carbohydrates a day.
Any study on this?
There is a lot of studies (long running, with large size populations) claiming the opposite. Here some arguments: http://www.masteringdiabetes.org/ketosis-ketogenic-diets-mis...
> - Hydroponically grown carrots taste gross.
Personal taste. It prolly has less phytonutrients. Not sure how this is an important consideration.
I'm not at all saying there's no use for keto, I just think it should never be a mainstream diet (but something applied in specific cases, under medical supervision). As far as sci evidence goes, WFPB seems to be the "best" diet for the human species as a whole.
This diet recommends a pound of fatty meat per day: http://perfecthealthdiet.com/the-diet/
The book that describes the diet cites over 1000 studies and empirical evidence to prove that the diet is healthy. Now who am I to believe?
https://nutritionfacts.org/2011/09/12/dr-gregers-2011-optimu...
Massive individual genetic testing and constant cellphone behavior monitoring might be able to produce decent studies in the future for your specific attributes, but for now advice from parents and grandparents may be the best you can do.
If you want to take a deep dive into a subject, search for a recent paper on the subject and as you read it the paper will reference other papers, especially in the introduction. Here is where you can find possibly a more relevant paper on the subject. Read that paper and repeat. Soon you will have a decent idea of what is going on in the field. Hard to do if you don't know the jargon and the mathematical methods though.
But I believe intermittent fasting where you eat the same 2,000 calories but just shorten the window of eating to allow your body to crank-up the growth hormone and start autophagy does have long-term benefits, that should lead to prolonged life.
And of course, a calorie isn't a calorie. If you eat 200g of net carbs a day, intermittent fasting probably won't prolong your life too much, but it's also going to be more difficult to do IF when you're body is used to having high-levels of blood sugar and insulin in it.
I think the modern life has maxed out as much life extension as we are going to get from our nutrition and lifestyle. We need to do interventional genetic modification to see any further improvements.
Common sense is often mistaken. Here are two rat poisons which are also medicines:
Ergocalciferol -- a.k.a. Vitamin D2 (used as a supplement for many years; now D3 is preferred)
Warfarin -- oral anticoagulant widely in use today
Don't salt your food _at all_ to maintain a healthy blood pressure.
>Furthermore, it also found that populations with low average daily salt intakes had low BP (blood pressure) and very little or no increase in BP with age. INTERSALT study indicates that BP increases with age only if accompanied by increased salt intake.
I just turned 50 but am regularly assumed to be 36, the age everyone always guess... including by my gf's parents who are just a few years older than me. I am a rather crazy outlier though, I actually enjoy working out and do a hundred+ pull-ups a week, and even on my light workout days tend to do at least 20 or so just to loosen up a bit.
The problem with having a healthy lifestyle is that our lives aren't statistics. Big number theory does not apply, we only have one draw, one life and if it happens that we are one of those unlucky ones to get lung cancer while never having smoked or generally lead a healthy life then we still die within a year and there's nothing we can do about it.
Any drastic lifestyle change has costs: serious time, commitment, money and we sacrifice opportunities, things that we could be doing/enjoying instead. So my advice is: for anyone deciding to drastically change their lifestyle to a "healthier" one, do so for all the _other_ reasons (feeling fit and good, looking younger, improved relationships, having more energy, etc) but not expecting for that to increase your life span. Because then you may be up for a one nasty disappointment when cancer strikes and you are left wondering why did you do all that, why did you sacrifice so much. You better have a good answer when that happens is what I'm saying. :) (and that is true no matter what lifestyle you lead)
The first is to sincerely imagine that I will die in 10 years. That's far enough away not to require drastic changes in my life — I still want to work hard on something that I'm passionate about — but close enough to remind me not to fuck around and take these years for granted. There's also a bonus that, if I do happen to run into some bad luck and have my life expectancy cut short, then it won't come as such a shock, because I've been living like it's my last decade anyway. And if that doesn't come to pass and I live a normal life, I'll feel more gratitude for it.
The second trick I use is to imagine that reincarnation is true, but that instead of "coming back" as plankton or a bug or another person, I come back as me and relive my life, over and over again, forever. In that situation, I'd want to optimize to have a great quality of life, and spend as little of it as possible worrying about my inevitable death, or agonizing over things that have gone wrong in my past. Since my rebirth is inevitable, I'd just be dooming myself to future agonizing. It sounds morbid, but I've found that this helps me to recover a bit when I feel down about something.
Would you not throw yourself down and gnash your teeth and curse the demon who spoke thus? Or have you once experienced a tremendous moment when you would have answered him: "You are a god and never have I heard anything more divine." If this thought gained possession of you, it would change you as you are or perhaps crush you. The question in each and every thing, "Do you desire this once more and innumerable times more?" would lie upon your actions as the greatest weight. Or how well disposed would you have to become to yourself and to life to crave nothing more fervently than this ultimate eternal confirmation and seal?
Friedrich Nietzsche, The Gay Science
I'm kind of taking the 80 / 20 approach to living healthy. Don't smoke. Don't eat too too much. Sleep well. See the doctor each year. I'll let you know how it goes.
Don't you have problems keeping warm, sleeping, and maintaining muscle mass at that level of calorie deficit?
Also wondering what your supplementations are. I take Vit D, Zinc, pre/probiotics but having an aggressive vitamin routine isn't considered ideal these days.
Next time we met they were both taking their metformin, although intermittently and apparently somewhat reluctantly. One of them was late for our meeting. In way of explanation he said that he had taken a metformin tablet just before driving off but, on the way, a fart proved to be untrustworthy: he had to drive back home and changed his pants.
I've heard the drug termed "metfartmin" b/c of its effects on the GI tract.
An even stronger data point to me would be the actual people of Okinawa who are (were?) among the healthiest and oldest in the world.
In addition to having a high quality diet and a rich social life in general, they are practicing “hara hachi bu” – the confucian tradition of always eating only until “about 80% full”.
Here is a cancer.com (American Cancer Society) article on the relationship between AIDS and cancer.
Source: https://www.cancer.org/cancer/cancer-causes/infectious-agent...
Firstly, they say that "In fact, some types of cancer occur so often in people with AIDS that they are considered AIDS-defining conditions".
But that's only certain specific cancers. Then there are some other cancers that occur often with AIDS but are not "AIDS-defining".
And then there is the kicker: "Of course, as people with HIV are now living longer, they are also developing other cancers that are not clearly linked to HIV but are more common in older people, such as breast, colorectal, and prostate cancer.".
So, these cancers go up in AIDS survivors due to age, even though those people have immune systems that were already shot years before.
So much for a tidy hypothesis about aging -> lower immune system -> cancer, I suppose.
As for why those afflicted with AIDS get certain cancers, one explanation (also given in above page) is that some cancers are caused by viral infections. Weakened defense against viral infections, increased cancer of that type.
https://doi.org/10.1371/journal.pgen.1007108
"Recent single-cell studies point to the possibility that essentially all cells have unshared mutations in their genomes. In view of this extensive genetic diversity, it is perhaps not surprising that mutations that confer a proliferative advantage are readily detected as clonal populations of increasing abundance and size in the elderly. These clonal populations might lead to loss of organismal health through the functional decline of tissue and/or the promotion of disease processes, such as cancer. In this review, we summarize recent research that supports the notion that aberrant clonal expansion (ACE) resulting from cancer-associated mutations are common in noncancerous tissue and accumulate with age. We propose ACE to be a previously underappreciated aging phenotype that is universal in most organisms, affects multiple tissues, and likely helps explain why aging is the biggest risk factor for cancer."
Also, in the intro you say "the risk of skin cancer increases exponentially with age and is associated with accumulation of somatic mutations8". Your source groups ages into only 3 categories... If you look closer at the data you will see that developing most cancers becomes less common in old age (peaks at 60 - 90 years old). For cancers involving tissue like bone or reproductive organs this peaks much earlier, probably due to when the majority of cell divisions are occurring.
Until it doesn't.
I would wager the opposite is true. Body systems maintain themselves and their fitness and function through use.
The obvious examples are bone and muscle tissue that become stronger through stress but are you aware that breast cancer incidence is strongly, negatively correlated to frequency and duration of breastfeeding ?
The immune system is also a bodily system and I would be surprised if it did not, also, strengthen itself and maintain its function through stresses and use.
"For example, curing the common cold and/or developing a universal flu vaccine."
Be careful what you wish for ...
We "cured" hard physical labor and traditional life patterns with lots of walking and standing. How's that working out for us ?
I'll bite -- terribly. Many of the millennial generation and younger are actively starting to revolt against these sedentary lifestyles. It's why fitness and fitness culture is so marketable these days, much more than I remember. I think the studies that came out showing the millennial were the first generation since the industrial revolution to have a decreased life expectancy versus the prior generation was a real wakeup call.
I like rsync's main point though about the immune system maybe requiring usage and callibration (gojomo mentions the hygiene hypothesis). Perhaps one day we'll determine the precise amount of these required (if any) for us to be healthy without being bothered by too much sickness.
* the hygiene hypothesis suggests that allergies and auto-immune disorders can arise from having insufficient immune-system challenges, especially when young. Lacking the calibration from an 'expected' or 'optimal' level of dirt/allergens/infectious-diseases, the immune system starts doing unwanted self-destructive things.
* hormesis is the observation that almost everything bad for you also turns out to be good in very-tiny exposures – radiation, poisons, cancer-causing chemicals, etc. It's as if tiny doses trigger beneficial self-repairs to occur even beyond the direct damage received, even as larger doses overwhelm that mechanism.
Removing mild, survivable challenges from the environment could thus leave the immune system less 'tuned' for the full spectrum of challenges it faces (like clearing early cancers). It's an adaptive dynamic system with nonlinear effects, not a simple pool of fixed exhaustible capability.
Exactly. You want to protect people from, say, Rubella ... but I think we should proceed with caution with things like the cold and the flu ...
http://dx.doi.org/10.1016/j.chom.2017.03.002
Not all pathogens are equal; cytomegalovirus may be far more important than the rest:
https://doi.org/10.3389/fimmu.2017.01953
And historically, reducing the burden of infectious disease already has increased life expectancy and reduced/postponed incidence of age-related disease:
http://www.slate.com/articles/health_and_science/science_of_...
There's a huge variability in terms of your thymus (the organ that produces new T cells) getting switched off after your mid 20s. For some people its almost immediate. For others, it takes many decades: https://insight.jci.org/articles/view/93739/figure/5
Tweaking this process, without breaking anything else, would be huge to extend our lifespan with some good quality years.
However, it does not seem to make a significant difference in lifespans.
Moral of this story, figure out how to tell all the anti-vaccination people they are wrong in some way they will believe. (the first is easy, the latter is impossible in my experience)
Die, per nature's capricious designs.
Robo-you lives smugly without any of this nonsense and can be resurrected if the power cuts out and sent across the stars at light speed with no need for fuel or supplies--breathes
... to somewhere without air.
Here is the classic review paper on tumor formation: http://www.cell.com/abstract/S0092-8674(11)00127-9
Live long enough and you will eventually get cancer.
To me it's a no-brainer. You get old, cells break down, immune system isn't what it use to be, increasing the risk of that rouge new cell becoming cancerous.
https://gravityandlevity.wordpress.com/2009/07/08/your-body-...
Is this where the blood transfusion concept is strong?
What is the oxygen-carrying-capacity of hemoglobin in old blood vs young blood?
Which is a suggestive model, by the way, not direct evidence. The best direct evidence would be to restore the pace of immune cell creation - such as via regeneration of the thymus (via FOXN1, or BMP4, or tissue engineering), cell therapy to replace or increase the pool of hematopoietic stem cells, etc. - and then see what happens. This sort of thing is five years out; there are people working on it, though more of those and more funding would certainly be a good thing. It would certainly be possible to push forward a startup today based on thymic regeneration or hematopoietic stem cell transplantation; the science is more or less ready for it.
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T cells develop from hematopoietic stem cells as part of the lymphoid lineage and have the ability to detect foreign antigens and neoantigens arising from cancer cells. In the thymus, lymphoid progenitors commit to a specific T cell receptor and undergo selection events that screen against self-reactivity. Cells that pass these selection gates then leave the thymus, clonally expanding to form the patrolling naive T cell pool.
The vast majority of vertebrates experience thymic involution (or atrophy) in which thymic epithelial tissue is replaced with adipose tissue, resulting in decreasing T cell export from the thymus. In humans, this is thought to begin as early as 1 year of age. The rate of thymic T cell production is estimated to decline exponentially over time with a half-life of ∼15.7 years. Declining production of new naive T cells is thought to be a significant component of immunosenescence, the age-related decline in immune system function. With the recent successes of T cell-based immunotherapies, it is timely to assess how thymic involution may affect cancer and infectious disease incidence.
It is clear from epidemiological data that incidence of infectious disease and cancer increases dramatically with age, and, specifically, that many cancer incidence curves follow an apparent power law. The simplest model to account for this assumes that cancer initiation is the result of a gradual accumulation of rare "driver" mutations in one single cell. Furthermore, the fitting of this power law model (PLM) can be used to estimate the number of such mutations. Exponential curves have also been used to fit cancer incidence data, resulting in worse fits than the PLM overall. Nevertheless, it is worth noting that exponential rates close to the declining curve for thymic T cell production can be seen to emerge from the incidence data, indicating the relevance of the thymic involution timescale. While the PLM fits well, it does not account for changes in the immune system with age. To better determine the processes underlying carcinogenesis, we asked whether an alternative model, based only on age-related changes in immune system function, might partly or entirely explain cancer incidence.
Our model outperforms the power law model with the same number of fitting parameters in describing cancer incidence data across a wide spectrum of different cancers, and provides excellent fits to infectious disease data. Our hypothesis and results add to the understanding of infectious disease and cancer incidence, suggesting in the latter case that immunosenescence, rather than gradual accumulation of mutations, serves as the predominant reason for an increase in cancer incidence with age for many cancers. For future therapies, including preventative therapies, strengthening the functionality of the aging immune system appears to be more feasible than limiting genetic mutations, which raises hope for effective new treatments.
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I'll summarize it: "We don't understand cancer but we'll keep throwing shit at the wall until something sticks, and we're going to write up a bunch of shit and you shits read it so we can pay for throwing more shit."