Some seem to think experiments show smoking causes cancer in animals. Not so, for mice or rats: I review the results of a representative selection of chronic inhalation studies with rats and mice exposed to mainstream cigarette smoke. … Smoke-induced epithelial hypertrophy, hyperplasia, and squamous metaplasia were reported in the conducting airways in most of the studies, along with increased numbers of intra-alveolar macrophages that were occasionally associated with alveolar metaplasia. Lung adenomas and adenocarcinomas were reported in only a few of the studies. No statistically significant increase in the incidence of malignant lung tumors was seen. …
I smoked for 23 years, in June 2014 i was diagnosed of Emphysema, i constantly go out of breath and lost my Job in 2015 due to this condition, this continued till a friend of mine told me about Ejiro Herbal Home, according to her she bought Glaucoma herbal medicine from Ejiro Herbal Home that totally cured her mother, so i decided to give it a try too. I was given Dr Ejiro's mobile number and i called him and explained my condition, he recommended a COPD herbal remedy which he said its 100% guaranteed to cure me. I bought this herbal remedy and received it in less than 2 weeks, It was 3 weeks program, i used it as prescribed and was surprised how i gradually gained back my health like the herbal medicine was some sort of magical medicine. All thanks to Ejiro herbal home, contact Ejiro Herbal Home via their website or email ejiroherbalcure(at)gmail(dot)com or call +27617403481 (write email in right format)
I too was suprised to find out that all attempts to create lung cancers had failed in animinal models when I first read about it from looking
through the evidence given in the McTear case. I was taught at school that
the tobacco companies had known that animal studies showed tobacco smoke to be carcinogenic but had suppressed the information. Clearly this was utter nonsense. But what is more confusing is that in murine models life expectancy of tobacco smoke exposed animals is increased over controls see the kaplan meier survival curve at the botom of the post in this surreal discussion here. In addition to animal studies causing confusion in the issue of causation, I find it odd that in country such as Sweden that took up smoking some 30 years later than a country such as the USA experiences a lung cancer epidemic at exactly the same time as the US, ~1950, as can be seen on my blog here.
Correct. COPD has classically been defined as comprising both emphysema and chronic bronchitis (although now a broader umbrella definition is preferred). My sense is that not many epidemiological studies of COPD have sought to separate out risk factors for the emphysema and chronic bronchitis components, but I am by no means expert in this literature.
Does COPD include emphysema? I was under the impression that emphysema was an uncontroversial effect of smoking, and almost as deadly as cancer in its extreme forms.
It seems to me that the Animals tested do not live long enough to get lung cancer from smoking. From what I have read, there is almost no increased mortality due to smoking before the age of 30 which generally 10 to 15 years in from starting. So I am not surprised that Animals do not show increased mortality due to smoking.
Right -- because you aren't trying to kill the mice. You're trying to evoke COPD so you can a) examine the biology, b) see if your test compound has effect. These animals for sure have inflammation and airway pathology suggestive of human COPD.
Here's one well-done observational study on the relationship of smoking to COPD.
TI Developing COPD: a 25 year follow up study of the general population.AU Lokke A; Lange P; Scharling H; Fabricius P; Vestbo JSO Thorax. 2006 Nov;61(11):935-9.
BACKGROUND: Smokers are more prone to develop chronic obstructive pulmonary disease (COPD) than non-smokers, but this finding comes from studies spanning 10 years or less. The aim of this study was to determine the 25 year absolute risk of developing COPD in men and women from the general population. METHODS: As part of the Copenhagen City Heart Study, 8045 men and women aged 30-60 years with normal lung function at baseline were followed for 25 years. Lung function measurements were collected and mortality from COPD during the 25 year observation period was analysed. RESULTS: The percentage of men with normal lung function ranged from 96% of never smokers to 59% of continuous smokers; for women the proportions were 91% and 69%, respectively. The 25 year incidence of moderate and severe COPD was 20.7% and 3.6%, respectively, with no apparent difference between men and women. Smoking cessation, especially early in the follow up period, decreased the risk of developing COPD substantially compared with continuous smoking. During the follow up period there were 2912 deaths, 109 of which were from COPD. 92% of the COPD deaths occurred in subjects who were current smokers at the beginning of the follow up period. CONCLUSION: The absolute risk of developing COPD among continuous smokers is at least 25%, which is larger than was previously estimated.
Those are interesting, but they don't seem to be measuring animal mortality, right? We have many conflicting reasons here; I'm trying to sort them out.
I found many sources admitting we haven’t found much evidence smoking hurts animals
A tobacco-smoke exposure model is an industry standard system for evaluating COPD medicines. There is of course concern about the transferability of findings in these systems to the human disease state. But pharmas and biotechs are using these models to direct multi-million dollar development decisions.
It would be helpful for Robin to clarify what hypothesis he is advancing. Is it:
1) We do not have reason to believe smoking increases risk for any health problem 2) We do not have reason to believe smoking increases risk for lung cancer specifically3) We have reason to believe both 1 and 2, but the magnitude of the risk is less certain than we imagine
I smoked for 23 years, in June 2014 i was diagnosed of Emphysema, i constantly go out of breath and lost my Job in 2015 due to this condition, this continued till a friend of mine told me about Ejiro Herbal Home, according to her she bought Glaucoma herbal medicine from Ejiro Herbal Home that totally cured her mother, so i decided to give it a try too. I was given Dr Ejiro's mobile number and i called him and explained my condition, he recommended a COPD herbal remedy which he said its 100% guaranteed to cure me. I bought this herbal remedy and received it in less than 2 weeks, It was 3 weeks program, i used it as prescribed and was surprised how i gradually gained back my health like the herbal medicine was some sort of magical medicine. All thanks to Ejiro herbal home, contact Ejiro Herbal Home via their website or email ejiroherbalcure(at)gmail(dot)com or call +27617403481 (write email in right format)
Robin
I too was suprised to find out that all attempts to create lung cancers had failed in animinal models when I first read about it from looking
through the evidence given in the McTear case. I was taught at school that
the tobacco companies had known that animal studies showed tobacco smoke to be carcinogenic but had suppressed the information. Clearly this was utter nonsense. But what is more confusing is that in murine models life expectancy of tobacco smoke exposed animals is increased over controls see the kaplan meier survival curve at the botom of the post in this surreal discussion here. In addition to animal studies causing confusion in the issue of causation, I find it odd that in country such as Sweden that took up smoking some 30 years later than a country such as the USA experiences a lung cancer epidemic at exactly the same time as the US, ~1950, as can be seen on my blog here.
"Curiouser and curiouser" said Alice.
As hamsters, rats and dogs have lifespans much shorter than humans, perhaps they are not exposed to smoke for long enough to produce damage.
Exactly my thoughts.
If there's a button I can push that would kill every mass murderer, I'd press it.
Wait, what decision-theoretic problem was all of this isomorphic to, again?
The brisket yarmulke, just in case:
http://www.royalbaconsociet...
Yes this review author works for a tobacco firm, but his papers seem professional.
this is a riot. good one!
Correct. COPD has classically been defined as comprising both emphysema and chronic bronchitis (although now a broader umbrella definition is preferred). My sense is that not many epidemiological studies of COPD have sought to separate out risk factors for the emphysema and chronic bronchitis components, but I am by no means expert in this literature.
COPD certainly has a significant disease burden. http://www.who.int/mediacen...
Just in case.
Does COPD include emphysema? I was under the impression that emphysema was an uncontroversial effect of smoking, and almost as deadly as cancer in its extreme forms.
It seems to me that the Animals tested do not live long enough to get lung cancer from smoking. From what I have read, there is almost no increased mortality due to smoking before the age of 30 which generally 10 to 15 years in from starting. So I am not surprised that Animals do not show increased mortality due to smoking.
Right -- because you aren't trying to kill the mice. You're trying to evoke COPD so you can a) examine the biology, b) see if your test compound has effect. These animals for sure have inflammation and airway pathology suggestive of human COPD.
Here's one well-done observational study on the relationship of smoking to COPD.
TI Developing COPD: a 25 year follow up study of the general population.AU Lokke A; Lange P; Scharling H; Fabricius P; Vestbo JSO Thorax. 2006 Nov;61(11):935-9.
BACKGROUND: Smokers are more prone to develop chronic obstructive pulmonary disease (COPD) than non-smokers, but this finding comes from studies spanning 10 years or less. The aim of this study was to determine the 25 year absolute risk of developing COPD in men and women from the general population. METHODS: As part of the Copenhagen City Heart Study, 8045 men and women aged 30-60 years with normal lung function at baseline were followed for 25 years. Lung function measurements were collected and mortality from COPD during the 25 year observation period was analysed. RESULTS: The percentage of men with normal lung function ranged from 96% of never smokers to 59% of continuous smokers; for women the proportions were 91% and 69%, respectively. The 25 year incidence of moderate and severe COPD was 20.7% and 3.6%, respectively, with no apparent difference between men and women. Smoking cessation, especially early in the follow up period, decreased the risk of developing COPD substantially compared with continuous smoking. During the follow up period there were 2912 deaths, 109 of which were from COPD. 92% of the COPD deaths occurred in subjects who were current smokers at the beginning of the follow up period. CONCLUSION: The absolute risk of developing COPD among continuous smokers is at least 25%, which is larger than was previously estimated.
http://thorax.bmj.com/conte...
Those are interesting, but they don't seem to be measuring animal mortality, right? We have many conflicting reasons here; I'm trying to sort them out.
I found many sources admitting we haven’t found much evidence smoking hurts animals
A tobacco-smoke exposure model is an industry standard system for evaluating COPD medicines. There is of course concern about the transferability of findings in these systems to the human disease state. But pharmas and biotechs are using these models to direct multi-million dollar development decisions.
http://chestjournal.chestpu...
http://ajplung.physiology.o...
It would be helpful for Robin to clarify what hypothesis he is advancing. Is it:
1) We do not have reason to believe smoking increases risk for any health problem 2) We do not have reason to believe smoking increases risk for lung cancer specifically3) We have reason to believe both 1 and 2, but the magnitude of the risk is less certain than we imagine
Warning: Eric Taylor once had to eat his hat after making a remark like that. ;)