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Smoking Permanently Damages Your DNA, Study Finds (nbcnews.com)
An anonymous reader quotes a report from NBC News: Smoking scars DNA in clear patterns, researchers reported Tuesday. Most of the damage fades over time, they found -- but not all of it. Their study of 16,000 people found that while most of the disease-causing genetic footprints left by smoking fade after five years if people quit, some appear to stay there forever. The marks are made in a process called methylation, which is an alteration of DNA that can inactivate a gene or change how it functions -- often causing cancer and other diseases. The team examined blood samples given by 16,000 people taking part in various studies going back to 1971. In all the studies, people have given blood samples and filled out questionnaires about smoking, diet, lifestyle and their health histories. They found smokers had a pattern of methylation changes affecting more than 7,000 genes, or one-third of known human genes. Many of the genes had known links to heart disease and cancers known to be caused by smoking. Among quitters, most of these changes reverted to the patterns seen in people who never smoked after about five years, the team reported in the American Heart Association journal Circulation: Cardiovascular Genetics. But smoking-related changes in 19 genes, including the TIAM2 gene linked to lymphoma, lasted 30 years, the team found.
Would the same be true of people who were exposed to coal smoke for long periods?
Yes, life cut short by wine drinking, that's why the country with the highest per capita consumption of wine, Andorra, has the shortest life....oh wait they have the highest don't they. And Vatican City and France and Slovenia ....all consume more wine than Americans and live longer too
They don't answer the only question we care about.
Heritability.
If it doesn't damage your kids genes ...and by extension, pollute the human genome ...then I don't care if you are dumb enough to damage your own health.
Unless you are a close relative, or smoke around me, it's no skin off my nose, if you want to commit suicide by cigarette or a Kevorkian death machine.
Man, you reek of smuggery. Hopefully that's not heritable, because future generations will be fucked.
The cytosine methylation signal along a strand of DNA is theoretically heritable, even though it has nothing to do with the actual sequence of bases.
There are vast stretches of junk DNA in the genome, some with old genes for ancient viruses or parasitic sequences like transposons, and the way the cell keeps those parts of DNA away from cell machinery is by methylating the cytosine residues. The methyl groups prevent RNA polymerase from transcribing the DNA and therefore it gets silenced.
When a cell divides, the methyl groups are only on the original strand; the new complimentary strand doesn't have any. The methylation signal has to be actively transcribed from one strand to another; an enzyme runs up the DNA feeling for methylated cytosine residues. When it finds some, it starts methylating any cytosine residues that might be nearby on the opposite strand, to make sure the troublesome regions all stay commented out. That's why it's heritable.
What is it about "tobacco" smoke that causes this change in DNA, but maybe not caused by marijuana smoke? Or smog? Or eating sugar? Or getting vaccines?
Could it be caused by the additives? The pesticides? The rolling paper? Is it the carbon monoxide? The nicotine? Or does the tobacco plant simply contain the perfect storm of noxious compounds?
Ok, so what? Another article that says "smoking is bad." Not constructive-- it's just another excuse for people to dogpile onto the boogey man that is tobacco without actually finding the facts, curing addiction, or improving smoking products.
People do not smoke because they think it's smart and healthy. Some people do it because it's social. Others do it because they've been affected by clever marketing as youngsters and have gone years without realizing their Marlboro Man self-image is actually just nicotine addiction. One thing is for sure: being a smug asshole and being rude to people who smoke for one reason or another does not deter them at all-- it reinforces the desire to smoke because the cigarette makes them feel better than anti-smokers' negativity. A cigarette merely offends the smoker's physiology, while smug assholes offend the smoker's very soul.
People have been imbibing tobacco products for hundreds of years. It is obvious the vast majority of us have adapted to its use.
Time is what keeps everything from happening all at once.
"pollute the human genome" Nice one, Hitler!
We already prohibit general use of a number of medical interventions based on transplanting porcine cells into humans.
For example, it's possible to exploit the immune privilege of the brain in order to transplant fetal pig brain cells into humans to treat conditions such as Parkinson's, Huntington's and islet cells into the pancreas of people with Type I diabetes.
The big risk is Porcine endogenous retrovirus (PERV -- yes, it's actually called that), being transmitted, and becoming part of the human genome. Thus, people who have received these xenografts are prohibited from sexual reproduction post-graft (although it's possible to save germ cells prior, to permit in vitro fertilization techniques).
See also:
Porcine xenografts in Parkinson's disease and Huntington's disease patients: preliminary results.
http://www.ncbi.nlm.nih.gov/pu...
So yes, numb-nuts: "pollute the human genome".
It's not Hitlerian, or in any way related to eugenics to prevent introduction of DNA errors or endogenous viruses into the general genome in a heritable way.
When a cell divides, the methyl groups are only on the original strand; the new complimentary strand doesn't have any. The methylation signal has to be actively transcribed from one strand to another; an enzyme runs up the DNA feeling for methylated cytosine residues. When it finds some, it starts methylating any cytosine residues that might be nearby on the opposite strand, to make sure the troublesome regions all stay commented out. That's why it's heritable.
The methylation inactivation is heritable. The issue, in this case, was erroneous activation or switching of cells to modify protein production.
I suspect that the mechanism involved (they don't say) in the repair of the genes which end up going back to normal is related to the production of O6-methyl-transferase via the MGMT complex sites on the long arm of c21 -- the same thing that results in chemo-resistance to cancers, such as pancreatic cancer or glioblastoma, when combined with the appropriate mutation of the p53 gene on c17.
I think as long as it doesn't involve a long term mutation of a cancer related gene, such that it effect the germ cells, it's not a problem. Since you tend to come pre-packed with all the germ cells you are ever going to have in your lifetime, then the issue will be smoking by pregnant women, and all other damage that results in disease will only be self-inflicted diseases, rather than heritable.
Which still means they've failed to answer the question of whether or not it's heritable, because they've failed to discuss whether or not it impacts germ cells (arguably unlikely, but it'd be nice to have an answer, particularly when making decisions on how and when to regulate smoking, or minimally, smoking in public).
Obviously it's too early to say exactly how safe vaping is, however we know smoking tobacco is incredibly bad for you and we know most of the ingredients in e-liquids are (relatively) safe on their own.
While there have been studies showing negative effects they tend to be rife with methodological flaws (running the e-cigs while dry, not replacing coils at the point they're burnt out, or using unrealistic dosages). I expect these studies get away with questionable methodology because we know how bad cigarettes are and no body wants to risk giving e-cigarettes a pass. Having said that there are some well designed studies which suggest vaping has it's own risks, there was a study showing the immune system of mice is temporarily suppressed by the vapour which seemed pretty solid (although that isn't my area so I may be wrong).
So while it's a mistake to say that vaping is definitely 95% safer than smoking, whatever that actually means, it's sensible to say it's probably significantly safer.
So, you *don't* eat snails and frogs legs in real life?
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife