18 ms·

Smoking “causes hundreds of DNA changes”

207 points by MichalSikora 10y ago

fithisux 10y ago
So, why do they sell cigarettes?
- mobiuscog 10y ago
  Money
- 6502nerdface 10y ago
  People vary in what gives them pleasure and in their valuation of the time/pleasure trade-off. Cigarettes are a tool for some people to move pleasure from the future to the present (i.e., shorter life/less future pleasure in exchange for more pleasure now); they adress intertemporal pleasure-flow needs for some, much as loans address intertemporal cashflow.
  - rubicon33 10y ago
    One of the best explanations I have ever heard, for why someone might choose to smoke.
  - darksavant 10y ago
    I absolutely loved this explanation.
- DominikR 10y ago
  It is not your business to decide what other people should do with their lives. Go live in North Korea or Venezuela if you desire having a dear leader who tells you what you should do with your life and leave us alone.
  - SketchySeaBeast 10y ago
    I guess the difficulty with this is that we're faced with groups that are actively telling us what to do by ways of advertising. They ask more nicely, and are at times much less obvious, but it's still has a great influence.
    - umanwizard 10y ago
      I'm perfectly fine with cigarette advertising being illegal, mandatory blank packages, and so on. I'd be very angry if they completely banned cigarettes, though.
      - SketchySeaBeast 10y ago
        Me too. I'm just weary of it appealing via marketing to those without the skills to fully understand their choices or to understand that their are being advertised to, like children.
    - DominikR 10y ago
      Then move to North Korea, I already wrote this before. If you want to live here you either accept that you are in a society of free people who actually have a free will or you move somewhere else where you'll find like minded drones serving their dear leader who in turn takes care of them like a father figure. We are not going to give up our freedom and turn into weak minded persons just to accommodate you.
      - SketchySeaBeast 10y ago
        I'm not even in your country, and honestly, I don't want to live there. Where you see people shouting "freedom" the loudest, I see fear, distrust, and anger. I'm just pointing out that no one is as free as you think you are because you always have influences. But I appreciate your willingness for open thought and reflection.
        DominikR 10y ago
        You just "point it out" to convince me to casually accept regulating other peoples or other companies freedom to advertise away because you suppose that people are just sheep who can't help being controlled by it. On top of that you probably do not even realise that you are arguing here for limiting freedom of speech. > Where you see people shouting "freedom" the loudest, I see fear, distrust, and anger. Am I supposed to feel bad now? I don't, I still want to keep freedom of speech. > I'm just pointing out that no one is as free as you think you are because you always have influences. Ominous and sometimes invisible influencers everywhere. Best way to deal with it: Censorship.
  - tirant 10y ago
    As If in other countries they don't tell you what you should do with your life.
    - pavanred 10y ago
      As if they don't tell you what you should do with your life in the US.
      - DominikR 10y ago
        Tell you or order you? I wrote "nobody gets the right to decide for someone else".
        pavanred 10y ago
        Well, here's how I see it. I understand what you are trying to say, it is not your (or anyone's) business to decide what other people should do with their lives, specially if it doesn't affect others. And, so no one (or governments) should intervene and regulate/ban sale of cigarettes. Would you feel absolutely the same way about all banned substances? If not, well you should agree that different people would draw the line differently.
        DominikR 10y ago
        > Would you feel absolutely the same way about all banned substances? Yes, absolutely. If people want to ruin their lives it's not my responsibility to keep them from doing it. It's their own decision and all consequences are their own problem.
        pavanred 10y ago
        This is an absolutist view, while it is quite a compelling argument for certain extreme cases, I am afraid the world is never that black and white. Since we are talking about regulating/banning substances, let me try to point it out with a relevant example. While it might seem fair to say that if someone wants to ruin their own life by substance abuse, why should it be my (or the government's) responsibility to keep them from doing it. But, consider this, one of the growing problems right now in the US is opioid dependence and addiction. In these cases, these opioids are medication that is prescribed by doctors to treat acute pain. But, along with providing pain relief, this medication can cause opioid dependence and addiction over time. A sizable population of regular people who were just seeking treatment for their illness, unfortunately ended up with opioid addiction. This could just as easily happen to any of us or our loved ones. I can't speak for you but I would definitely want the government to step in, fund relevant research to study the problem, based on that perhaps regulate (or ban, if necessary) the availability and/or prescription of such medication because though it provides pain relief, it has unintended consequences that ruin lives of unsuspecting people. Government regulation isn't necessarily always bad. There is no absolutist one-size-fits-all solution for all problems. Would I like the government to tell me what I can and cannot do, absolutely not. I would protest with you if I think government is overreaching. But, would I concede that there are certain issues (which might not affect me, but might affect lot of others) where the government has to intervene, of course, yes.
- umanwizard 10y ago
  Why do they sell richly marbled steak when we know it causes high cholesterol?
  - JoeAltmaier 10y ago
    I don't think it actually does. That was just 'sympathetic magic' - you eat cholesterol, it doesn't really end up in your blood vessel lining?
    - umanwizard 10y ago
      Red meat doesn't cause high cholesterol? Huh? No offense, but unless you post some really reputable source, I'm gonna trust my cardiologist over some guy on the internet.
      - JoeAltmaier 10y ago
        I guess the last few years of news contradicting that fat is bad for you, salt is bad for you and so on had made me believe the legend was long ago punctured. Here's a bunch of references: http://www.sciencedirect.com/science/article/pii/S0309174014001922 http://www.sciencedirect.com/science/article/pii/S0309174014...
      - rhinoceraptor 10y ago
        I would look into Ancel Keys and the diet heart hypothesis. This idea isn't, and never was grounded in evidence. It's based on very poor science done in the 20th century. The old guard of doctors and health officials will be looked at in the same way we look at geocentrists now. They hold a lot of the blame for the current obesity crisis we have.
        deleted 10y ago
        [deleted]
- nom 10y ago
  Because people like to smoke. It's more than pleasurable, but only iff you are able to either ignore or accept the consequences (or you are simply not aware of them).
fithisux 10y ago
Smoking causes COPD too.
melling 10y ago
What about the study that said 15 years after you quit smoking, your chances of dying are the same? https://www.yahoo.com/beauty/are-former-smokers-safe-after-15-years-121685128937.html https://www.yahoo.com/beauty/are-former-smokers-safe-after-1...
ommunist 10y ago
A significant amount of the shredded brown innards of most modern cigarettes is a paper product called "reconstituted tobacco" or "homogenized sheet tobacco," which is made from a pulp of mashed tobacco stems and other parts of the tobacco leaf that would otherwise go to waste. Manufacturers spray and impregnate reconstituted tobacco paper with nicotine and other substances lost during the process, along with as many as 600 chemical additives. These include several that may come as a surprise, such as ammonia, which aids in the delivery of nicotine, and chocolate, which masks the bitter taste of tobacco. Finally, the 'recon' is sliced to resemble shredded leaf tobacco. So basically good research should compare people smoking quality cuban (once a week) with pipe smoker (once a day) with this poor creature addicted to synthetical 'tobacco' on her 20/day. And of course, since urban people are exposed to contaminated air from cars, control group must be taken from rural areas. I predict result that tobacco is not responsible for lung cancer, in absence of other air contamination factors. You know, more than 90% of people with lung cancer ate cucumbers. So think twice before blaming tobacco.
- kabouseng 10y ago
  Downvoted because you provided zero evidence and pure conjecture arguing against a by now well established fact - smoking causes cancer.
  - ommunist 10y ago
    No problem, mate, its a free country. I mean Russia, of course. In the US there are established opinions that firms censorship which you just exercised.
  - ommunist 10y ago
    Eat this http://www.journaloftheoretics.com/editorials/vol-1/e1-4.htm http://www.journaloftheoretics.com/editorials/vol-1/e1-4.htm No evidence that tobacco cause cancer.
    - chaosfox 10y ago
      * this is not a scientific paper, it an editorial * it was published in 1999 * in a very sketchy journal * did you even read what you linked ? it is arguing semantics: >If they would say that smoking increases the incidence of >lung cancer or that smoking is a risk factor in the >development of lung cancer, then I would agree. The >purpose of this article is to emphasize the need to use >language appropriately in both the medical and scientific >literature (the media, as a whole, may be a lost cause).
kawera 10y ago
I wonder if there were studies that analyzed the effect of smoking non-industrialized cigarettes. I smoke 2-4 cigarettes per day and make my own cigarettes from tobacco leaves that I dry/shred myself. The leaves in turn come from a few organically grown plants.
- mountaineer22 10y ago
  Also, you are controlling your own dose (by how big you roll and pack your cigarette), no? I feel with industrialized cigarettes, most users feel obligated to consume it completely. My father-in-law would smoke a portion of the cigarette, put it out, and resume later.
  - kawera 10y ago
    Oh, sure, you can control the size/dose - mines are slightly shorter/thinner than normal cigarettes.
- nabla9 10y ago
  The quality of tobacco does not matter. Homegrown can be even more harmful. The main reason tobacco is so dangerous is because you are inhaling smoke and carcinogens that are created in the burning. Burning organic or non-organic makes no difference. You are like firefighter in a burning house without a mask when you inhale. http://www.livescience.com/7914-warning-homegrown-tobacco-deadly.html http://www.livescience.com/7914-warning-homegrown-tobacco-de...
flukus 10y ago
So us smokers are more highly evolved? /s
- labster 10y ago
  Evolution doesn't have a high or low state, or a linear progression. It's a natural process that is random and responsive to environment changes, not progressing towards an ideal.
  - WaxProlix 10y ago
    If mutation is the engine of evolution, an increase in mutation should mean an increase in the speed of evolution. Obviously not on the scales we're talking about here, but the premise doesn't seem too unsound, external pressures being equal.
    - beedogs 10y ago
      Mutations can be beneficial, benign, or harmful. Smoking obviously only really creates the latter two.
      - mrpopo 10y ago
        That's definitely not obvious. I would agree that mutations due to smoking could be in majority harmful due to the chemical components and the high temperatures involved. Other than that, a mutation is a mutation, whether due to smoke, nuclear irradiation, high altitude, or chance. In all cases, they can be beneficial or harmful. The evolution process will then cause only the beneficial ones to perdure.
        RyanZAG 10y ago
        > The evolution process will then cause only the beneficial ones to perdure. This isn't correct and is a common misconception about evolution. The process which does this is natural selection, and it only occurs through the organism being unable to reproduce as well as an organism with beneficial evolutionary changes. With humans in the modern world, there is no natural selection because of state benefits that keep people alive and able to reproduce who would usually be unable to do so in a world without safety nets. So in the modern world, any evolution in humanity - either positive or negative - will perdure. In effect we've ended the traditional form of evolution ages ago when we became civilized.
trustfundbaby 10y ago
I wonder if drinking does the same?
- forgotpwagain 10y ago
  I would expect so. Alcohol can cause inflammation, triggering various parts of the immune system to kick in. This could result in the release of free radicals from these immune cells, which promotes DNA mutations.
  - TheSpiceIsLife 10y ago
    Alcohol (ethanol) is a Type 1 / Group A carcinogen.[1] 1. http://www.cancer.org/cancer/cancercauses/othercarcinogens/generalinformationaboutcarcinogens/known-and-probable-human-carcinogens http://www.cancer.org/cancer/cancercauses/othercarcinogens/g...
    - ommunist 10y ago
      And surprisingly no mass deaths from cancer of Russians or Irish were detected, with both nations famous for alcohol abuse. Yes, alcohol is harmful, but like Russians joke, it only kills weak brain cells.
      - tluyben2 10y ago
        Maybe a lot of people die before they get cancer from it? Like organ failure (liver, kidney, heart) way before they develop cancer (symptoms)? Or get into accidents (car, freezing to death) etc. It is like people saying smoking can prevent Alzheimer as statistically people who smoke a lot have less instances of it. Because they die from that habit before the Alzheimer shows up.
        a_plastic_bag 10y ago
        Alcohol isn't very carcinogenic, but I think it's been estimated that it's the cause in a few percent of cancer cases.
teamonkey 10y ago
Does anyone know the baseline rate for mutations for a non-smoker? Edit: Corrected autocorrect
- jjn2009 10y ago
  If you meant nonsmoker then you asked the most relevant metric in my opinion.
- CppCoder 10y ago
  I read the original study and yes, they did compare it to lifelong non-smokers. However, as far as I saw they only compared people with cancer. And the numbers were usually increased for smokers and the smokers usually ended up with more of a certain kind of cancer.
  - ommunist 10y ago
    Great. Were the groups stratified against occupation? Were the smokers with no cancer under study?
- pazimzadeh 10y ago
  "In the absence of mutagens, an average gene will mutate about once in a million generations. ~10^16 cell divisions occur in a typical life span so somewhere in cells that are part of you each of your genes has mutated 10^10 times (hence cancer). Only mutations in the germ line can be passed on to the next generation. You have about 50 mutations that your parents dont have (mutations that happened in the egg or sperm that made you up)-each of your parents in turn have passed on ~50 mutants that their parents dont have." Source: an email from my undergrad genetics professor
sidcool 10y ago
How addictive is tobacco/smoking as compared to Opiates/Heroin?
- fithisux 10y ago
  "Animal studies by NIDA-funded researchers have shown that acetaldehyde, another chemical found in tobacco smoke, dramatically increases the reinforcing properties of nicotine and may also contribute to tobacco addiction. The investigators further report that this effect is age-related: adolescent animals display far more sensitivity to this reinforcing effect, which suggests that the brains of adolescents may be more vulnerable to tobacco addiction."
- deleted 10y ago
  [deleted]
- raverbashing 10y ago
  Considering opiate withdraw can cause death I'd say tobacco is less addictive
  - mv 10y ago
    Opioid withdrawal while uncomfortable generally does not lead to death. However withdrawal from benzodiazepines and alcohol are both very dangerous and can lead to death. http://americanaddictioncenters.org/withdrawal-timelines-treatments/risk-of-death/ http://americanaddictioncenters.org/withdrawal-timelines-tre...
  - drvdevd 10y ago
    Actually I believe clinically, "addictiveness" is measured by what it takes to develop a dependence in the first place, rather that what it takes to get rid of that dependence or even the physical effects of an abrupt cessation. I heard somewhere (sorry no references) that by that measure, nicotine is one of if not the most addictive substance known.
    - bigpeopleareold 10y ago
venamresm__ 10y ago
That reminds me of the British information video: https://www.youtube.com/watch?v=sWfOLN9Z1yw https://www.youtube.com/watch?v=sWfOLN9Z1yw
Gatsky 10y ago
This has some legal implications. You can now prove fairly conclusively that your lung cancer came from smoking. I wonder if it will lead to a new wave of tobacco litigation. I think even Fisher would be convinced [1]. [1] https://priceonomics.com/why-the-father-of-modern-statistics-didnt-believe/ https://priceonomics.com/why-the-father-of-modern-statistics...
- TelmoMenezes 10y ago
  Smokers were already and for a long time aware of the risks. They choose to take them. What could they possibly claim? That a product known for causing lung cancer caused lung cancer?
  - Gatsky 10y ago
    That's a good point, I am not a lawyer so I can't really comment. But perhaps there is a material difference between saying you developed a disease that could have been caused by smoking (as lung cancer occurs in non-smokers), and saying you were definitely harmed by smoking. Other avenues could be: - Smoking is also associated with other cancers, such as esophageal cancer and bladder cancer. Generally the warnings don't mention this however. By examining the mutation patterns in an esophageal cancer, you could relate it more conclusively to smoking, and could therefore claim you were not warned about that specific risk. - Tissue samples from lung cancers diagnosed 20 or 30 years ago are sitting in archival storage. You could sequence the whole genome or exome of these tumours for about $1000 - $2000. Statute of limitations aside, sequencing these tumours could reveal the tobacco signature as a basis for a claim from a time when it was less clear or less public what the risks were. - Passive smokers could have a case if their cancer shows a tobacco signature.
    - deleted 10y ago
      [deleted]
    - umanwizard 10y ago
      Lung cancer is caused by smoking 85-90% of the time. Probably more if you add in secondhand smoke. I think it already meets any sort of "preponderance of evidence" sort of bar to just assume anyone with lung cancer got it from smoking.
Shivetya 10y ago
while there are some studies that do not put marijuana smoking as high on the danger list [1] I am really curious that as legalization increases what will we see in the future. Then of course there is the loosely regulated area of vaping and who knows what is in some of those fluids. For the most part I am quite sure they have to be safer than smoking but I would love some hard regulation. 2005 study on marijuana smoke > https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1277837/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1277837/
- ddorian43 10y ago
  You can always go for vaporizers. Are vaporizers actually ever used on tobaco? (i think they're sold "for tobaco use only" like bongs?)
  - ommunist 10y ago
    As a pipe smoker, I can tell that vaporisers work with synthetic liquids containing synthetical nicotine, nothing to do with harms and benefits of tobacco. You could use nicotine plasters with the same effect.
    - ddorian43 10y ago
      I was talking about vaporizers where you put the thing that you usually burn in there, not some kind of liquid. Example: http://sales.magic-flight.com/original-maple-launch-box-kit/ http://sales.magic-flight.com/original-maple-launch-box-kit/
      - ommunist 10y ago
        Thank you, interesting boxes. I understood that whole assembly works like portable shisha, which is a good way to smoke certain tobaccos.
- roflchoppa 10y ago
  Yeah my buddy has been thinking about moving over to just vaporizing marijuana, opposed to smoking it in papers. Might as well remove what you can?
ommunist 10y ago
What the author was smoking? 20 a day of what? Cigarettes? These things have nothing to do with tobacco. Cigarettes are purely synthetical things. The real research could compare say, avid snus user with cigars smoker with pipe smoker with cigarettes smoker with marijuana smoker, with non smoker exposed to industrial work, with non-smoker exposed to work in civil construction, and so on. Poor isolation of factors and lack of statistics are signs of fake research.
nonbel 10y ago
>'Prof Stratton said in these organs smoking seemed to be accelerating a natural mutational process, but how it did this was "mysterious and complex".' Wow, just wow. This is standard Armitage & Doll model that has been taught since the 1950s. Every time a cell divides there is some chance of a genetic error occurring. The more generations away from the zygote a cell is, the more genetic errors it will have accumulated. Activities that damage tissue, etc and necessitate cell division to replenish the cells will contain cells with more errors. Now that is a vague sketch, but many people have implemented mathematical/computational models based on that idea, beginning with Armitage and Doll in 1954. Unless he is going to reject the model that has been driving cancer research for half a century (which should be noted in the interview), there really is no mystery at all.
- scottishfiction 10y ago
  It would be unfair to assume Prof Stratton is unaware of this model, rather than simply tailoring a technical finding to a non-technical audience.
  - nonbel 10y ago
    It really is not a complex concept. If that is too "mysterious and complex" of a process for the audience to understand then I doubt there is much point attempting rational communication with them. Note: I think the vast majority of people could easily understand my sketch above.
    - QuantumRoar 10y ago
      There is a difference between using statistical models and understanding the underlying processes. I can tell someone that when we smash together Muons and nucleons that there is a certain chance that we will produce Kaons. That, I believe, many can understand. What I cannot explain briefly to a general audience is how quantum field theory and the standard model of particle physics works and how we can compute the probabilities from that. Just because you know that something is happening, doesn't mean you understand anything about the underlying processes involved.
pizza 10y ago
Anything similar about vaping/e-cigs?
- mathw 10y ago
  Not much literature on vaping as yet. However, British authorities currently consider vaping to be significantly safer than smoking, and encourage smokers to switch in order to help them quit. Also, vaping fluids don't contain the many, many compounds which are present in tobacco smoke and known to be dangerous, so it seems quite likely it's significantly safer. The unanswered questions are over what long-term inhalation of vaping fluid might do.
- indigo_rex 10y ago
  "E-cigarette vapour does not induce DNA mutations commonly observed with tobacco smoke exposures in lab-based tests." Yes. https://www.eurekalert.org/pub_releases/2016-11/raba-evd110416.php https://www.eurekalert.org/pub_releases/2016-11/raba-evd1104...
nonbel 10y ago
Unless I am misunderstanding something, their figure 3 seems to be plotting effect size vs p-value... So all it would be showing is that they had more data from lung adenocarcinomas (ie sample size is larger for that cancer type). It isn't 100% clear to me if they shared the data used for that figure, but here are the frequencies each cancer type appeared in table S1: Acute myeloid leukaemia (AML) Bladder 202 399 Cervix Colorectal cancer 168 559 Esophageal Adenocarcinoma Esophageal Squamous 242 292 Gastric cancer Kidney 472 257 Larynx Liver 123 392 Lung Adeno Lung Squamous 678 175 Oral cavity Ovarian cancer 363 458 Pancreas Pharynx 239 76 Small Cell Lung Cancer 148 It is essentially just figure 1 from here: https://arxiv.org/abs/1311.0081 https://arxiv.org/abs/1311.0081
- nonbel 10y ago
  Looking more I see: "Comparison of overall methylation between smokers and non-smokers was performed for all tobacco-associated cancer types for which there were available data from Illumina Infinium HumanMethylation450 BeadChip array, where each array contains 473,864 autosomal CpG probes. The examined data were downloaded from the original data source (Table S1) [...] distributions were subsequently compared between smokers and non-smokers using a two-sample Student’s t-test. Results were considered significant for Bonferroni threshold of 10-7." So it is not like figure one from that Lew paper, because their effect size is not normalized to the inter-individual variance. This is a point in their favor. However, the sample sizes do match up to those found in table S1 (which I posted above). From the data provided, we cannot tell whether that difference in p-values is solely due to sample size or not. They need to tell us the variance for each CpG/tissue combo as well.
drusepth 10y ago
So, could we detect what properties of smoking map to which DNA changes, and design a cigarette that maximizes net-positive DNA changes while minimizing harmful/negative ones?
- mtw 10y ago
  What are examples of net-positive DNA changes?
  - qb45 10y ago
    The ones that differentiated us from cabbage. At least positive for us, not sure if for cabbage ;) Though if you count only DNA changes in smokers' lungs, probably none. Or we would have found some superhuman abilities in smokers by now.
qb45 10y ago
Trivia: Polonium-210 in tobacco contributes to many of the cases of lung cancer worldwide. Most of this polonium is derived from lead-210 deposited on tobacco leaves from the atmosphere; the lead-210 is a product of radon-222 gas, much of which appears to originate from the decay of radium-226 from fertilizers applied to the tobacco soils. https://en.wikipedia.org/wiki/Polonium#Tobacco https://en.wikipedia.org/wiki/Polonium#Tobacco
- zymhan 10y ago
  Would organic tobacco avoid the issue of Polonium then?
  - deleted 10y ago
    [deleted]
  - pboutros 10y ago
    Only if organic fertilizer is immune to that.
    - zymhan 10y ago
      Yeah, I suppose a better question is what fertilizer is used on organic tobacco. But u/searine mentioned that mined phosphate can be used on organic crops so maybe organic tobacco won't avoid the problem.
  - qb45 10y ago
    That's an interesting question because it's the first time I hear about radium in artificial fertilizers. Will need to dig into these Wikipedia sources. That tobacco contains lead and polonium had been known for decades, but I used to think that it originated from the decay of natural atmospheric radon and these plants just had some unusual tendency to accumulate heavy metals. Maybe I should put my tinfoil hat on and run away from non-organic food too? edit: From the first source: Tobacco farmers in developed countries primarily use manufactured fertilizer high in phosphates produced from apatite rock that contains radium-226 and descendant radioisotopes such as lead-210 and PO-210. Tobacco is a unique agricultural crop in that its flavor depends on nitrogen reduction, which occurs through the repeated application of high-phosphate fertilizers. The higher the phosphate level of the fertilizer, the higher the concentration of PO-210 in the tobacco plant. Tobacco grown in certain developing countries has approximately one third less radioactivity than tobacco grown in developed countries, and the radioactivity of tobacco grown in the United States has increased over time. So maybe you are right.
norea-armozel 10y ago
Nice to know all that second hand smoke my dad exposed me to probably will wind up giving some kind of cancer. Thanks for the mutations dad. /s
zimbatm 10y ago
So how much more is it compared to a non-smoker? I understand the idea of shock factor but everyone gets mutations, it would be nice to get a baseline.
tonyplee 10y ago
Next Ad for Tobacco: If you smoke hard enough, you might become X-man.
sireat 10y ago
Is there anything you can do to help your odds of not dying from lung cancer once you have stopped smoking? Any yearly tests to perform? I was a 10cigs a day smoker for 15 years(quit some years ago) and it really weights heavy on my mind that there is nothing I can do about my past mistakes.
WheelsAtLarge 10y ago
I suspect there are multiple reasons for the DNA changes. One that comes to mind is the number of times the lungs have to repair themselves due to the tar and other contaminants. The hot smoke might even contribute to the tissue damage. Cancer is uncontrollable cell growth. The cell/body's ability to control a certain type of cell division has been lost. So, my thinking is, in the same way that you lose quality as you make a copy of a copy in a copy machine the same happens to the cell's DNA. The more a cell has to divide the less the DNA can remain without errors. DNA can tolerate a number of errors but it can eventually lead to cancer. My guess is that not one issues causes the DNA changes but and array of them given the number of substances a cigarette has.

207 points by MichalSikora 10y ago

fithisux 10y ago

So, why do they sell cigarettes?

mobiuscog 10y ago
Money
6502nerdface 10y ago
People vary in what gives them pleasure and in their valuation of the time/pleasure trade-off. Cigarettes are a tool for some people to move pleasure from the future to the present (i.e., shorter life/less future pleasure in exchange for more pleasure now); they adress intertemporal pleasure-flow needs for some, much as loans address intertemporal cashflow.
- rubicon33 10y ago
  One of the best explanations I have ever heard, for why someone might choose to smoke.
- darksavant 10y ago
  I absolutely loved this explanation.
DominikR 10y ago
It is not your business to decide what other people should do with their lives. Go live in North Korea or Venezuela if you desire having a dear leader who tells you what you should do with your life and leave us alone.
- SketchySeaBeast 10y ago
  I guess the difficulty with this is that we're faced with groups that are actively telling us what to do by ways of advertising. They ask more nicely, and are at times much less obvious, but it's still has a great influence.
  - umanwizard 10y ago
    I'm perfectly fine with cigarette advertising being illegal, mandatory blank packages, and so on. I'd be very angry if they completely banned cigarettes, though.
    - SketchySeaBeast 10y ago
      Me too. I'm just weary of it appealing via marketing to those without the skills to fully understand their choices or to understand that their are being advertised to, like children.
  - DominikR 10y ago
    Then move to North Korea, I already wrote this before. If you want to live here you either accept that you are in a society of free people who actually have a free will or you move somewhere else where you'll find like minded drones serving their dear leader who in turn takes care of them like a father figure. We are not going to give up our freedom and turn into weak minded persons just to accommodate you.
    - SketchySeaBeast 10y ago
      I'm not even in your country, and honestly, I don't want to live there. Where you see people shouting "freedom" the loudest, I see fear, distrust, and anger. I'm just pointing out that no one is as free as you think you are because you always have influences. But I appreciate your willingness for open thought and reflection.
      - DominikR 10y ago
        You just "point it out" to convince me to casually accept regulating other peoples or other companies freedom to advertise away because you suppose that people are just sheep who can't help being controlled by it. On top of that you probably do not even realise that you are arguing here for limiting freedom of speech. > Where you see people shouting "freedom" the loudest, I see fear, distrust, and anger. Am I supposed to feel bad now? I don't, I still want to keep freedom of speech. > I'm just pointing out that no one is as free as you think you are because you always have influences. Ominous and sometimes invisible influencers everywhere. Best way to deal with it: Censorship.
- tirant 10y ago
  As If in other countries they don't tell you what you should do with your life.
  - pavanred 10y ago
    As if they don't tell you what you should do with your life in the US.
    - DominikR 10y ago
      Tell you or order you? I wrote "nobody gets the right to decide for someone else".
      - pavanred 10y ago
        Well, here's how I see it. I understand what you are trying to say, it is not your (or anyone's) business to decide what other people should do with their lives, specially if it doesn't affect others. And, so no one (or governments) should intervene and regulate/ban sale of cigarettes. Would you feel absolutely the same way about all banned substances? If not, well you should agree that different people would draw the line differently.
        DominikR 10y ago
        > Would you feel absolutely the same way about all banned substances? Yes, absolutely. If people want to ruin their lives it's not my responsibility to keep them from doing it. It's their own decision and all consequences are their own problem.
        pavanred 10y ago
        This is an absolutist view, while it is quite a compelling argument for certain extreme cases, I am afraid the world is never that black and white. Since we are talking about regulating/banning substances, let me try to point it out with a relevant example. While it might seem fair to say that if someone wants to ruin their own life by substance abuse, why should it be my (or the government's) responsibility to keep them from doing it. But, consider this, one of the growing problems right now in the US is opioid dependence and addiction. In these cases, these opioids are medication that is prescribed by doctors to treat acute pain. But, along with providing pain relief, this medication can cause opioid dependence and addiction over time. A sizable population of regular people who were just seeking treatment for their illness, unfortunately ended up with opioid addiction. This could just as easily happen to any of us or our loved ones. I can't speak for you but I would definitely want the government to step in, fund relevant research to study the problem, based on that perhaps regulate (or ban, if necessary) the availability and/or prescription of such medication because though it provides pain relief, it has unintended consequences that ruin lives of unsuspecting people. Government regulation isn't necessarily always bad. There is no absolutist one-size-fits-all solution for all problems. Would I like the government to tell me what I can and cannot do, absolutely not. I would protest with you if I think government is overreaching. But, would I concede that there are certain issues (which might not affect me, but might affect lot of others) where the government has to intervene, of course, yes.
umanwizard 10y ago
Why do they sell richly marbled steak when we know it causes high cholesterol?
- JoeAltmaier 10y ago
  I don't think it actually does. That was just 'sympathetic magic' - you eat cholesterol, it doesn't really end up in your blood vessel lining?
  - umanwizard 10y ago
    Red meat doesn't cause high cholesterol? Huh? No offense, but unless you post some really reputable source, I'm gonna trust my cardiologist over some guy on the internet.
    - JoeAltmaier 10y ago
      I guess the last few years of news contradicting that fat is bad for you, salt is bad for you and so on had made me believe the legend was long ago punctured. Here's a bunch of references: http://www.sciencedirect.com/science/article/pii/S0309174014001922 http://www.sciencedirect.com/science/article/pii/S0309174014...
    - rhinoceraptor 10y ago
      I would look into Ancel Keys and the diet heart hypothesis. This idea isn't, and never was grounded in evidence. It's based on very poor science done in the 20th century. The old guard of doctors and health officials will be looked at in the same way we look at geocentrists now. They hold a lot of the blame for the current obesity crisis we have.
      - deleted 10y ago
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nom 10y ago
Because people like to smoke. It's more than pleasurable, but only iff you are able to either ignore or accept the consequences (or you are simply not aware of them).

fithisux 10y ago

Smoking causes COPD too.

melling 10y ago

What about the study that said 15 years after you quit smoking, your chances of dying are the same? https://www.yahoo.com/beauty/are-former-smokers-safe-after-15-years-121685128937.html https://www.yahoo.com/beauty/are-former-smokers-safe-after-1...

ommunist 10y ago

A significant amount of the shredded brown innards of most modern cigarettes is a paper product called "reconstituted tobacco" or "homogenized sheet tobacco," which is made from a pulp of mashed tobacco stems and other parts of the tobacco leaf that would otherwise go to waste. Manufacturers spray and impregnate reconstituted tobacco paper with nicotine and other substances lost during the process, along with as many as 600 chemical additives. These include several that may come as a surprise, such as ammonia, which aids in the delivery of nicotine, and chocolate, which masks the bitter taste of tobacco. Finally, the 'recon' is sliced to resemble shredded leaf tobacco. So basically good research should compare people smoking quality cuban (once a week) with pipe smoker (once a day) with this poor creature addicted to synthetical 'tobacco' on her 20/day. And of course, since urban people are exposed to contaminated air from cars, control group must be taken from rural areas. I predict result that tobacco is not responsible for lung cancer, in absence of other air contamination factors. You know, more than 90% of people with lung cancer ate cucumbers. So think twice before blaming tobacco.

kabouseng 10y ago
Downvoted because you provided zero evidence and pure conjecture arguing against a by now well established fact - smoking causes cancer.
- ommunist 10y ago
  No problem, mate, its a free country. I mean Russia, of course. In the US there are established opinions that firms censorship which you just exercised.
- ommunist 10y ago
  Eat this http://www.journaloftheoretics.com/editorials/vol-1/e1-4.htm http://www.journaloftheoretics.com/editorials/vol-1/e1-4.htm No evidence that tobacco cause cancer.
  - chaosfox 10y ago
    * this is not a scientific paper, it an editorial * it was published in 1999 * in a very sketchy journal * did you even read what you linked ? it is arguing semantics: >If they would say that smoking increases the incidence of >lung cancer or that smoking is a risk factor in the >development of lung cancer, then I would agree. The >purpose of this article is to emphasize the need to use >language appropriately in both the medical and scientific >literature (the media, as a whole, may be a lost cause).

kawera 10y ago

I wonder if there were studies that analyzed the effect of smoking non-industrialized cigarettes. I smoke 2-4 cigarettes per day and make my own cigarettes from tobacco leaves that I dry/shred myself. The leaves in turn come from a few organically grown plants.

mountaineer22 10y ago
Also, you are controlling your own dose (by how big you roll and pack your cigarette), no? I feel with industrialized cigarettes, most users feel obligated to consume it completely. My father-in-law would smoke a portion of the cigarette, put it out, and resume later.
- kawera 10y ago
  Oh, sure, you can control the size/dose - mines are slightly shorter/thinner than normal cigarettes.
nabla9 10y ago
The quality of tobacco does not matter. Homegrown can be even more harmful. The main reason tobacco is so dangerous is because you are inhaling smoke and carcinogens that are created in the burning. Burning organic or non-organic makes no difference. You are like firefighter in a burning house without a mask when you inhale. http://www.livescience.com/7914-warning-homegrown-tobacco-deadly.html http://www.livescience.com/7914-warning-homegrown-tobacco-de...

flukus 10y ago

So us smokers are more highly evolved? /s

labster 10y ago
Evolution doesn't have a high or low state, or a linear progression. It's a natural process that is random and responsive to environment changes, not progressing towards an ideal.
- WaxProlix 10y ago
  If mutation is the engine of evolution, an increase in mutation should mean an increase in the speed of evolution. Obviously not on the scales we're talking about here, but the premise doesn't seem too unsound, external pressures being equal.
  - beedogs 10y ago
    Mutations can be beneficial, benign, or harmful. Smoking obviously only really creates the latter two.
    - mrpopo 10y ago
      That's definitely not obvious. I would agree that mutations due to smoking could be in majority harmful due to the chemical components and the high temperatures involved. Other than that, a mutation is a mutation, whether due to smoke, nuclear irradiation, high altitude, or chance. In all cases, they can be beneficial or harmful. The evolution process will then cause only the beneficial ones to perdure.
      - RyanZAG 10y ago
        > The evolution process will then cause only the beneficial ones to perdure. This isn't correct and is a common misconception about evolution. The process which does this is natural selection, and it only occurs through the organism being unable to reproduce as well as an organism with beneficial evolutionary changes. With humans in the modern world, there is no natural selection because of state benefits that keep people alive and able to reproduce who would usually be unable to do so in a world without safety nets. So in the modern world, any evolution in humanity - either positive or negative - will perdure. In effect we've ended the traditional form of evolution ages ago when we became civilized.

trustfundbaby 10y ago

I wonder if drinking does the same?

forgotpwagain 10y ago
I would expect so. Alcohol can cause inflammation, triggering various parts of the immune system to kick in. This could result in the release of free radicals from these immune cells, which promotes DNA mutations.
- TheSpiceIsLife 10y ago
  Alcohol (ethanol) is a Type 1 / Group A carcinogen.[1] 1. http://www.cancer.org/cancer/cancercauses/othercarcinogens/generalinformationaboutcarcinogens/known-and-probable-human-carcinogens http://www.cancer.org/cancer/cancercauses/othercarcinogens/g...
  - ommunist 10y ago
    And surprisingly no mass deaths from cancer of Russians or Irish were detected, with both nations famous for alcohol abuse. Yes, alcohol is harmful, but like Russians joke, it only kills weak brain cells.
    - tluyben2 10y ago
      Maybe a lot of people die before they get cancer from it? Like organ failure (liver, kidney, heart) way before they develop cancer (symptoms)? Or get into accidents (car, freezing to death) etc. It is like people saying smoking can prevent Alzheimer as statistically people who smoke a lot have less instances of it. Because they die from that habit before the Alzheimer shows up.
      - a_plastic_bag 10y ago
        Alcohol isn't very carcinogenic, but I think it's been estimated that it's the cause in a few percent of cancer cases.

teamonkey 10y ago

Does anyone know the baseline rate for mutations for a non-smoker? Edit: Corrected autocorrect

jjn2009 10y ago
If you meant nonsmoker then you asked the most relevant metric in my opinion.
CppCoder 10y ago
I read the original study and yes, they did compare it to lifelong non-smokers. However, as far as I saw they only compared people with cancer. And the numbers were usually increased for smokers and the smokers usually ended up with more of a certain kind of cancer.
- ommunist 10y ago
  Great. Were the groups stratified against occupation? Were the smokers with no cancer under study?
pazimzadeh 10y ago
"In the absence of mutagens, an average gene will mutate about once in a million generations. ~10^16 cell divisions occur in a typical life span so somewhere in cells that are part of you each of your genes has mutated 10^10 times (hence cancer). Only mutations in the germ line can be passed on to the next generation. You have about 50 mutations that your parents dont have (mutations that happened in the egg or sperm that made you up)-each of your parents in turn have passed on ~50 mutants that their parents dont have." Source: an email from my undergrad genetics professor

sidcool 10y ago

How addictive is tobacco/smoking as compared to Opiates/Heroin?

fithisux 10y ago
"Animal studies by NIDA-funded researchers have shown that acetaldehyde, another chemical found in tobacco smoke, dramatically increases the reinforcing properties of nicotine and may also contribute to tobacco addiction. The investigators further report that this effect is age-related: adolescent animals display far more sensitivity to this reinforcing effect, which suggests that the brains of adolescents may be more vulnerable to tobacco addiction."
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raverbashing 10y ago
Considering opiate withdraw can cause death I'd say tobacco is less addictive
- mv 10y ago
  Opioid withdrawal while uncomfortable generally does not lead to death. However withdrawal from benzodiazepines and alcohol are both very dangerous and can lead to death. http://americanaddictioncenters.org/withdrawal-timelines-treatments/risk-of-death/ http://americanaddictioncenters.org/withdrawal-timelines-tre...
- drvdevd 10y ago
  Actually I believe clinically, "addictiveness" is measured by what it takes to develop a dependence in the first place, rather that what it takes to get rid of that dependence or even the physical effects of an abrupt cessation. I heard somewhere (sorry no references) that by that measure, nicotine is one of if not the most addictive substance known.
  - bigpeopleareold 10y ago

venamresm__ 10y ago

That reminds me of the British information video: https://www.youtube.com/watch?v=sWfOLN9Z1yw https://www.youtube.com/watch?v=sWfOLN9Z1yw

Gatsky 10y ago

This has some legal implications. You can now prove fairly conclusively that your lung cancer came from smoking. I wonder if it will lead to a new wave of tobacco litigation. I think even Fisher would be convinced [1]. [1] https://priceonomics.com/why-the-father-of-modern-statistics-didnt-believe/ https://priceonomics.com/why-the-father-of-modern-statistics...

TelmoMenezes 10y ago
Smokers were already and for a long time aware of the risks. They choose to take them. What could they possibly claim? That a product known for causing lung cancer caused lung cancer?
- Gatsky 10y ago
  That's a good point, I am not a lawyer so I can't really comment. But perhaps there is a material difference between saying you developed a disease that could have been caused by smoking (as lung cancer occurs in non-smokers), and saying you were definitely harmed by smoking. Other avenues could be: - Smoking is also associated with other cancers, such as esophageal cancer and bladder cancer. Generally the warnings don't mention this however. By examining the mutation patterns in an esophageal cancer, you could relate it more conclusively to smoking, and could therefore claim you were not warned about that specific risk. - Tissue samples from lung cancers diagnosed 20 or 30 years ago are sitting in archival storage. You could sequence the whole genome or exome of these tumours for about $1000 - $2000. Statute of limitations aside, sequencing these tumours could reveal the tobacco signature as a basis for a claim from a time when it was less clear or less public what the risks were. - Passive smokers could have a case if their cancer shows a tobacco signature.
  - deleted 10y ago
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  - umanwizard 10y ago
    Lung cancer is caused by smoking 85-90% of the time. Probably more if you add in secondhand smoke. I think it already meets any sort of "preponderance of evidence" sort of bar to just assume anyone with lung cancer got it from smoking.

Shivetya 10y ago

while there are some studies that do not put marijuana smoking as high on the danger list [1] I am really curious that as legalization increases what will we see in the future. Then of course there is the loosely regulated area of vaping and who knows what is in some of those fluids. For the most part I am quite sure they have to be safer than smoking but I would love some hard regulation. 2005 study on marijuana smoke > https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1277837/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1277837/

ddorian43 10y ago
You can always go for vaporizers. Are vaporizers actually ever used on tobaco? (i think they're sold "for tobaco use only" like bongs?)
- ommunist 10y ago
  As a pipe smoker, I can tell that vaporisers work with synthetic liquids containing synthetical nicotine, nothing to do with harms and benefits of tobacco. You could use nicotine plasters with the same effect.
  - ddorian43 10y ago
    I was talking about vaporizers where you put the thing that you usually burn in there, not some kind of liquid. Example: http://sales.magic-flight.com/original-maple-launch-box-kit/ http://sales.magic-flight.com/original-maple-launch-box-kit/
    - ommunist 10y ago
      Thank you, interesting boxes. I understood that whole assembly works like portable shisha, which is a good way to smoke certain tobaccos.
roflchoppa 10y ago
Yeah my buddy has been thinking about moving over to just vaporizing marijuana, opposed to smoking it in papers. Might as well remove what you can?

ommunist 10y ago

What the author was smoking? 20 a day of what? Cigarettes? These things have nothing to do with tobacco. Cigarettes are purely synthetical things. The real research could compare say, avid snus user with cigars smoker with pipe smoker with cigarettes smoker with marijuana smoker, with non smoker exposed to industrial work, with non-smoker exposed to work in civil construction, and so on. Poor isolation of factors and lack of statistics are signs of fake research.

nonbel 10y ago

>'Prof Stratton said in these organs smoking seemed to be accelerating a natural mutational process, but how it did this was "mysterious and complex".' Wow, just wow. This is standard Armitage & Doll model that has been taught since the 1950s. Every time a cell divides there is some chance of a genetic error occurring. The more generations away from the zygote a cell is, the more genetic errors it will have accumulated. Activities that damage tissue, etc and necessitate cell division to replenish the cells will contain cells with more errors. Now that is a vague sketch, but many people have implemented mathematical/computational models based on that idea, beginning with Armitage and Doll in 1954. Unless he is going to reject the model that has been driving cancer research for half a century (which should be noted in the interview), there really is no mystery at all.

scottishfiction 10y ago
It would be unfair to assume Prof Stratton is unaware of this model, rather than simply tailoring a technical finding to a non-technical audience.
- nonbel 10y ago
  It really is not a complex concept. If that is too "mysterious and complex" of a process for the audience to understand then I doubt there is much point attempting rational communication with them. Note: I think the vast majority of people could easily understand my sketch above.
  - QuantumRoar 10y ago
    There is a difference between using statistical models and understanding the underlying processes. I can tell someone that when we smash together Muons and nucleons that there is a certain chance that we will produce Kaons. That, I believe, many can understand. What I cannot explain briefly to a general audience is how quantum field theory and the standard model of particle physics works and how we can compute the probabilities from that. Just because you know that something is happening, doesn't mean you understand anything about the underlying processes involved.

pizza 10y ago

Anything similar about vaping/e-cigs?

mathw 10y ago
Not much literature on vaping as yet. However, British authorities currently consider vaping to be significantly safer than smoking, and encourage smokers to switch in order to help them quit. Also, vaping fluids don't contain the many, many compounds which are present in tobacco smoke and known to be dangerous, so it seems quite likely it's significantly safer. The unanswered questions are over what long-term inhalation of vaping fluid might do.
indigo_rex 10y ago
"E-cigarette vapour does not induce DNA mutations commonly observed with tobacco smoke exposures in lab-based tests." Yes. https://www.eurekalert.org/pub_releases/2016-11/raba-evd110416.php https://www.eurekalert.org/pub_releases/2016-11/raba-evd1104...

nonbel 10y ago

Unless I am misunderstanding something, their figure 3 seems to be plotting effect size vs p-value... So all it would be showing is that they had more data from lung adenocarcinomas (ie sample size is larger for that cancer type). It isn't 100% clear to me if they shared the data used for that figure, but here are the frequencies each cancer type appeared in table S1: Acute myeloid leukaemia (AML) Bladder 202 399 Cervix Colorectal cancer 168 559 Esophageal Adenocarcinoma Esophageal Squamous 242 292 Gastric cancer Kidney 472 257 Larynx Liver 123 392 Lung Adeno Lung Squamous 678 175 Oral cavity Ovarian cancer 363 458 Pancreas Pharynx 239 76 Small Cell Lung Cancer 148 It is essentially just figure 1 from here: https://arxiv.org/abs/1311.0081 https://arxiv.org/abs/1311.0081

nonbel 10y ago
Looking more I see: "Comparison of overall methylation between smokers and non-smokers was performed for all tobacco-associated cancer types for which there were available data from Illumina Infinium HumanMethylation450 BeadChip array, where each array contains 473,864 autosomal CpG probes. The examined data were downloaded from the original data source (Table S1) [...] distributions were subsequently compared between smokers and non-smokers using a two-sample Student’s t-test. Results were considered significant for Bonferroni threshold of 10-7." So it is not like figure one from that Lew paper, because their effect size is not normalized to the inter-individual variance. This is a point in their favor. However, the sample sizes do match up to those found in table S1 (which I posted above). From the data provided, we cannot tell whether that difference in p-values is solely due to sample size or not. They need to tell us the variance for each CpG/tissue combo as well.

drusepth 10y ago

So, could we detect what properties of smoking map to which DNA changes, and design a cigarette that maximizes net-positive DNA changes while minimizing harmful/negative ones?

mtw 10y ago
What are examples of net-positive DNA changes?
- qb45 10y ago
  The ones that differentiated us from cabbage. At least positive for us, not sure if for cabbage ;) Though if you count only DNA changes in smokers' lungs, probably none. Or we would have found some superhuman abilities in smokers by now.

qb45 10y ago

Trivia: Polonium-210 in tobacco contributes to many of the cases of lung cancer worldwide. Most of this polonium is derived from lead-210 deposited on tobacco leaves from the atmosphere; the lead-210 is a product of radon-222 gas, much of which appears to originate from the decay of radium-226 from fertilizers applied to the tobacco soils. https://en.wikipedia.org/wiki/Polonium#Tobacco https://en.wikipedia.org/wiki/Polonium#Tobacco

zymhan 10y ago
Would organic tobacco avoid the issue of Polonium then?
- deleted 10y ago
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- pboutros 10y ago
  Only if organic fertilizer is immune to that.
  - zymhan 10y ago
    Yeah, I suppose a better question is what fertilizer is used on organic tobacco. But u/searine mentioned that mined phosphate can be used on organic crops so maybe organic tobacco won't avoid the problem.
- qb45 10y ago
  That's an interesting question because it's the first time I hear about radium in artificial fertilizers. Will need to dig into these Wikipedia sources. That tobacco contains lead and polonium had been known for decades, but I used to think that it originated from the decay of natural atmospheric radon and these plants just had some unusual tendency to accumulate heavy metals. Maybe I should put my tinfoil hat on and run away from non-organic food too? edit: From the first source: Tobacco farmers in developed countries primarily use manufactured fertilizer high in phosphates produced from apatite rock that contains radium-226 and descendant radioisotopes such as lead-210 and PO-210. Tobacco is a unique agricultural crop in that its flavor depends on nitrogen reduction, which occurs through the repeated application of high-phosphate fertilizers. The higher the phosphate level of the fertilizer, the higher the concentration of PO-210 in the tobacco plant. Tobacco grown in certain developing countries has approximately one third less radioactivity than tobacco grown in developed countries, and the radioactivity of tobacco grown in the United States has increased over time. So maybe you are right.

norea-armozel 10y ago

Nice to know all that second hand smoke my dad exposed me to probably will wind up giving some kind of cancer. Thanks for the mutations dad. /s

zimbatm 10y ago

So how much more is it compared to a non-smoker? I understand the idea of shock factor but everyone gets mutations, it would be nice to get a baseline.

tonyplee 10y ago

Next Ad for Tobacco: If you smoke hard enough, you might become X-man.

sireat 10y ago

Is there anything you can do to help your odds of not dying from lung cancer once you have stopped smoking? Any yearly tests to perform? I was a 10cigs a day smoker for 15 years(quit some years ago) and it really weights heavy on my mind that there is nothing I can do about my past mistakes.

WheelsAtLarge 10y ago

I suspect there are multiple reasons for the DNA changes. One that comes to mind is the number of times the lungs have to repair themselves due to the tar and other contaminants. The hot smoke might even contribute to the tissue damage. Cancer is uncontrollable cell growth. The cell/body's ability to control a certain type of cell division has been lost. So, my thinking is, in the same way that you lose quality as you make a copy of a copy in a copy machine the same happens to the cell's DNA. The more a cell has to divide the less the DNA can remain without errors. DNA can tolerate a number of errors but it can eventually lead to cancer. My guess is that not one issues causes the DNA changes but and array of them given the number of substances a cigarette has.