Smoking, smokeless tobacco and cancer (2)

My previous post discussed toxin delivery from different tobacco products. Now what is the evidence relating use of these products to health problems? Unfortunately most studies don’t collect data on different brands or even categories of smokeless tobacco being used, and few compare directly the risks from smokeless with those from smoking. However, we can get a sense of the risks by examining studies based in different parts of the world where different types of tobacco are used. When we look at it this way we can find very clear evidence that the types of smokeless tobacco used in Sudan and India increase the risk of oral cancer. There is also toxicological evidence showing that Sudanese smokeless tobacco has very high concentrations of TSNAs (carcinogenic toxins), as do some forms of smokeless tobacco used in India. In Asia the picture is complicated by the tradition of adding other ingredients, especially areca nut which is highly carcinogenic on its own.

Then when we look at studies of smokeless tobacco use from the U.S. we see mixed results. One particular study published in the 1980s found very high risks of oral cancer. That study by Professor Deborah Winn and colleagues focused on women in southern United States and found that white never-smoking women (who tend to use oral dry snuff powder) had a relative risk of over 4.2 (2.6-6.7), for developing oral and pharyngeal cancer. Women who had used smokeless tobacco for 50 years had a 50-fold increase in risk for some oral cancers. It should be noted that only a tiny minority of smokeless users use the type of dry snuff tobacco that is commonly used by women in these rural parts of North Carolina. It should also be noted that the type of smokeless tobacco with the extremely high concentration of toxins mentioned in my previous post was also a type of dry snuff. So it begins to look like it’s the smokeless tobacco with very high toxin levels that has evidence of a causal effect on oral cancer. In fact, one of the largest studies on the effects of smokeless tobacco use in the United States (by the American Cancer Society) found no significant increase in the risk for oral cancer among smokeless tobacco users. One of these studies examined a population of 2488 smokeless tobacco users with a median age of 57 at enrolment (i.e. they'd used smokeless for decades) and followed them up 18 years later (i.e. mean age 75). This study found only one death from oral cancer in exclusive smokeless tobacco users, and none in former users, which was a slightly lower rate than occurred in people who had never used any tobacco in their life. These findings from the American Cancer Society suggest that any effect of commonly used brands of smokeless tobacco in the United States on oral cancer, if present, is relatively small.

Finally, we can examine the studies conducted in Sweden where the use of a form of low-toxin moist snuff (called snus) is more common than smoking in men. These studies consistently find no increased risk of oral cancer for snus users. One of the best of these studies was published in the Lancet recently and found that snus users have no increased risk of oral or lung cancer, but they have twice the risk of pancreatic cancer of never tobacco users. That same study found higher risks of all these cancers in smokers (e.g. smokers were about 10 times more likely to get lung cancer than either snus users or never tobacco users, who both had similar risks).

So now lets come back the recent report by Hecht and colleagues. It found similar concentrations of a specific carcinogen in smokeless users and smokers. But we have excellent data showing that smokers have much higher risks of lung cancer than smokeless users, and also higher risks of oral cancer than users of some forms of smokeless tobacco. The lung cancer pattern suggests that deposition of carcinogens directly into the lungs is relevant to the causal mechanism as smokeless tobacco has generally not been found to cause lung cancer in humans. But then we also have a higher risk of oral cancer for smokers. This causes one to consider whether the biomarker being measured in the urine in Hecht and colleague's study is very closely linked to the mechanism wherbye tobacco causes cancer in humans. Perhaps there are other toxins (e.g. benzo(a)pyrene) that are important in triggering cancer in smokers, but are found in lower levels in smokeless users? Whatever, the explanation, it seems that urine NNAL levels do not relate very closely to cancer risks in tobacco users.

But when discussing health risks from tobacco we need to be clear that these involve much more than lung or oral cancer, but also other cancers, and also other serious respiratory and cardiovascular diseases. For most of these, the health risks from smoking greatly outweigh the risks from smokeless tobacco. Chronic respiratory diseases are extremely common among smokers but there is neither good evidence nor a plausible rationale linking use of smokeless tobacco to these respiratory diseases.

So although it is clear that smokeless tobacco contains carcinogens and is not harmless, it is significantly less harmful than smoking cigarettes. I agree with Hecht and colleagues that we should not encourage anyone to use smokeless tobacco, when we have safe and effective medicines to help them quit smoking. However, I think we need to be able to give an honest answer to the question, “Are there forms of smokeless tobacco that are much less likely to kill me than smoking cigarettes?”. The honest answer is,”yes”. Similarly, of we are asked whether some types of smokeless tobacco may be less harmful than others, it seems prudent to suggest that some types of tobacco that have higher concentrations of toxins than others, and that the type of smokeless tobacco used in Sweden (snus) appears to be lower in toxins and health risks than much of the tobacco used in the rest of the world. It is far from risk-free (as are many things that people choose to do on a regular basis, like driving a car, eating donuts, drinking beer, mountain-climbing, or having sex), but experts agree that it is about 90% less harmful than smoking:
http://cebp.aacrjournals.org/cgi/content/full/13/12/2035
Similarly, given the relationship between toxin delivery and health effects from smokeless tobacco, it would seem to be sensible to regulate tobacco products in a manner that requires manufacturers to minimize the concentrations of toxins delivered as much as is technically possible.

In the mean time (and also after regulation is in place), manufacturers who produce and market products containing and delivering unnecessarily high quantities of toxins should be legally liable for the effects of their defective products.

Labels: cancer, smokeless, Smoking, tobacco

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Carcinogens from smoking and smokeless tobacco use (1)

This month an interesting study by Professor Stephen Hecht and colleagues at University of Minnesota was published in the journal, Cancer Epidemiology, Biomarkers & Prevention. The study compared cigarette smokers with smokeless tobacco users on their urine concentration of a biomarker of nicotine intake (cotinine, the main metabolite of nicotine), and a biomarker of exposure to a known carcinogen (NNAL, a biomarker of NNK exposure). The study found that the smokeless tobacco users had higher concentrations of the nicotine metabolite and higher concentrations of the carcinogen biomarker than smokers. The authors concluded that smokeless tobacco is not a safe substitute for smoking.

The authors are correct in this conclusion, as some forms of smokeless tobacco have been shown to be associated with oral cancer, other oral lesions, and may also increase some cardiovascular risks. The idea that smokeless tobacco is not safe is unlikely to be surprising to many people. But given that many of the major cigarette manufacturers are currently test-marketing smokeless tobacco products it may be worth examining the types and risks from smokeless tobacco in more detail, and also looking at how the epidemiological data relates to the recent findings from Hecht and colleagues.

The first thing that needs to be said about smokeless tobacco is that it is not just one thing. The extremely wide variety of different types of smokeless tobacco can be viewed on an excellent website produced by the U.S. National Cancer Institute and Centers for Disease Control, online at: www.cancercontrol.cancer.gov/tcrb/stfact_sheet_combined10-23-02.pdf.

Secondly, smokeless tobaccos vary enormously in the amount of toxins (including carcinogens) they deliver, and (not surprisingly) the ones containing higher concentrations of toxins (like carcinogenic tobacco-specific nitrosamines, or benzo(a)pyrene), appear to be more likely to have adverse health effects. To give an idea of the range of concentrations of toxins, Professor Brad Rodu at University of Louisville published data on the concentration of carcinogenic Tobacco-Specific Nitrosamines (TSNAs) in various smokeless tobacco products. Some examples are as follows (the units of measurement are parts per million based on dry weight):

Ariva (new powdered tobacco lozenge): <0.1 ppms
Ettan (Swedish snus): 2.0 ppms
Red Man (US chewing tobacco): 1.8 ppms
Copenhagen (leading US moist snuff): 12.1 ppms
Red Seal (US dry snuff): 1096 ppms

So we have here over a thousand-fold difference in the concentration of certain toxins in different types of smokeless tobacco! There are a few additional problems. Most of the smokeless tobacco products sold in the United States use fermentation in their production. This facilitates the development of carcinogenic compounds in the tobacco. In fact there is evidence to show that in these fermented products, they continue to ferment in the can, such that the concentration of carcinogens may increase in the can as it sits on the shelf. The method of production used for Swedish snus does not include fermentation, but rather uses a pasteurization-like process that treats the product with steam and appears to kill the microbes required for fermentation. This is thought to be the reason why Swedish snus has lower levels of carcinogens than US Smokeless tobacco. It may also be the reason that Swedish snus does not appear to cause oral cancer. However, the problem remains in the United States that the tobacco manufacturers can adjust the way they produce their products and the ingredients included in them without telling anyone. That is part of the reason why many experts support the pending legislation that would give the FDA the power to regulate tobacco products. This legislation appears to enable the FDA to require maximum permissible levels of harmful toxins in both smoked and smokeless tobacco products. With cigarettes the problem of what happens when you burn the product and inhale the smoke remains, but for smokeless there is a real prospect of offering a product that contains and delivers a known maximum level of toxins – and potentially a level that would be extremely unlikely to cause cancer. But for now, as demonstrated in Hecht and colleagues study, US smokeless tobacco delivers more toxins than necessary and there is little we can do about it.

In my next post I’ll discuss the relationship between the concentration of toxins in smokeless tobacco products and their harmfulness to health.

If you are interested in the views of tobacco and cancer experts on this topic you can learn more by reading the article linked below:
http://cebp.aacrjournals.org/cgi/content/full/13/12/2035

Labels: cancer, cigarette smoking, smokeless, tobacco

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Getting through the first few weeks

When people quit smoking it is very common for them to experience a temporary increase in certain unpleasant symptoms. The most common nicotine withdrawal symptoms are:
1. Irritability
2. Restlessness
3. Poor concentration
4. Depression
5. Increased appetite
6. Anxiety
7. Insomnia

I discussed these symptoms in previous posts:
What is nicotine withdrawal syndrome? 3/6/07
http://www.healthline.com/blogs/smoking_cessation/2007/03/what-is-nicotine-withdrawal-syndrome.html

Ten tips for coping with nicotine withdrawal. 3/7/07
http://www.healthline.com/blogs/smoking_cessation/2007/03/ten-tips-on-coping-with-tobacco.html

However, I’m bringing this topic up again because I’m noticing a number of people trying to quit smoking by using Chantix who are still experiencing some of the symptoms mentioned above but are concluding that these symptoms are caused by the medicine. Of course with any individual person the best way to figure out the cause of a new or worsening symptom is to discuss the problem in detail with your health professional. But in general, if someone has just quit smoking and they experience one of the symptoms mentioned above, the first explanation to consider is that it is a temporary nicotine withdrawal symptom caused by stopping smoking, rather than a symptom caused by a smoking cessation medicine.

Sometimes similar symptoms can be caused by smoking cessation medicines. For example, insomnia and vivid dreams can also be caused by the 24 hour nicotine patch and by bupropion (Zyban or Welbutrin). Chantix has also been known to cause vivid dreams. Generally, the heavier a smoker the person is, the more likely they will be to experience strong withdrawal symptoms, and the less likely their symptoms are caused by their medication. The opposite is also true. So if a 40-a day smoker experiences insomnia 2 days after quitting smoking while taking the standard dose of a smoking cessation medicine it is more likely to be due to nicotine withdrawal. If a 10 cigarettes per day smoker who never wakes at night to smoke and doesn’t smoke within half an hour of waking in the morning experienced the same insomnia it is might be caused by the medicine. In the case of the patch, they might want to try taking it off a few hours before going to bed, and in the case of Zyban or Chantix they might want to make sure they don’t take the second pill just before going to bed.

My main point here, however, is to caution against blaming the medicine for symptoms that it may actually be helping with, and then stopping using the medicine too soon. Any change in timing or dosage of a medicine should be discussed with your doctor first.

Similarly, it is tempting when a medicine is not giving complete relief of unpleasant symptoms like insomnia, anxiety or cravings to want to try another medicine as well. As always, a decision on what medicines are most likely to help you in any specific situation is best made after a full discussion between you and your doctor. However, when one of the symptoms mentioned above is the problem, and particularly if you were a heavy smoker and have recently quit, then the symptom is likely caused by nicotine withdrawal and will resolve by itself gradually over a couple of weeks. Medicines that have not been approved by the FDA or a similar medicines regulatory authority for smoking cessation will be unlikely to help much.

To tell if you are a “heavy smoker” check out my previous posts on that topic:
How addicted are you to cigarettes? (1) 5/19/07
http://www.healthline.com/blogs/smoking_cessation/2007/05/how-addicted-are-you-to-cigarettes-1.html

How addicted are you? (2) 5/19/07
http://www.healthline.com/blogs/smoking_cessation/2007/05/how-addicted-are-you-2.html

If you are a heavy smoker and are having a rough time quitting I’d strongly encourage you to get as much support as you possibly can. As well as speaking to your own personal health professional, I’d recommend a specialist face-to-face tobacco treatment service if there is one near you (they will have experts in smoking cessation counseling and medicines), as well as use of smoking cessation telephone helplines and internet sites, that were also discussed in previous posts:

Telephone quitlines: do they help smokers to quit? 4/19/07
http://www.healthline.com/blogs/smoking_cessation/2007/04/telephone-quitlines-do-they-help.html

Can smoking cessation internet sites help you to quit? 4/21/07
http://www.healthline.com/blogs/smoking_cessation/2007/04/can-smoking-cessation-internet-sites.html

Key things to remember during the rough times are:
A. Nicotine withdrawal symptoms are worst during the first couple of weeks after you completely quit tobacco and gradually calm down to be almost gone by the 4th week.
B. Each individual episode of craving for a cigarette typically lasts a few seconds, and rarely longer than a couple of minutes. Keeping yourself busy and actively switching your mind onto other things will help get rid of cravings more quickly.
C. Cravings are stimulated by being around tobacco and other people smoking. If you have any in the house, get rid of it. If you are hanging out in a place where people are smoking, hang out somewhere else!

You have probably put in quite alot of effort by the time you found this web-site. Don't throw it away by having a smoke. Keep going. It is tough but you can succeed.

Labels: Chantix, cigarette smoking, nicotine, patch, quitting, side-effects, symptoms, withdrawal, Zyban

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Thanks to Grand Rounds 3:47

Thank you to Christian Bachmann of Med Journal Watch for publishing my article on
Could smoking reduction improve your health? 7/27/07
http://www.healthline.com/blogs/smoking_cessation/2007/07/could-smoking-reduction-improve-your.html in his Grand Rounds 3:47 on Sudden Changes. Grand Rounds is a compilation of the best of medical-oriented blogs and this time the theme is change. There are 41 different blog entries highlighted. Have a look at:
http://medjournalwatch.blogspot.com/2007/08/grand-rounds.html

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Two new studies of Chantix (varenicline)

Two new trials of the smoking cessation medicine varenicline (Chantix) were published this past weekend. One reported the results in 515 nicotine-dependent Japanese smokers (mainly men) and the other reported the results in 250 Korean and Taiwanese smokers.

The Japanese study compared the outcomes across various doses of varenicline, with participants taking the pills for 12 weeks, and then being followed up for a further 40 weeks off drug. As in previous studies, the 1mg dose (twice daily) achieved slightly higher quit rates than lower doses, albeit with higher reported side-effects. The 1mg dose achieved abstinence rates of 65% at 12 weeks, as compared with 40% among those using placebo pills. At one year follow up, 35% of those who were given 1mg pills for the first 12 weeks remained abstinent, compared with 23% of those who had taken placebo pills. So this study in Japan confirmed the safety and efficacy of Chantix, but the “effect size” – the degree to which the drug performed better than placebo, was not quite as impressive as previous studies. This was partly because a relatively large proportion of Japanese smokers in this study succeeded in quitting while using placebo pills.

Another study based in Korea and Taiwan directly compared 12 weeks of 1mg varenicline with 12 weeks of placebo in 250 smokers (mainly men). After 12 weeks, 60% of those using varenicline were not smoking, compared with 32% of those using placebo pills. After 24 weeks (i.e. another 12 weeks “off drug”) the quit rate was 47% among those who had used varenicline, versus 22% among those who had used placebo. As in previous studies, those taking varenicline were more likely to report some nausea, constipation and abnormal dreams, but these were generally mild in nature. Also like prior studies, those on Chantix were not less likely to report an increased appetite. This is noteworthy as most previous smoking cessation medicines (such as nicotine replacement therapy or bupropion) tend to reduce appetite compared with placebo, and suggests that Chantix works via a slightly different mechanism.

So far, the placebo-controlled trials of varenicline have been remarkably consistent in finding that it approximately doubles quit rates compared with placebo, and that this increased quit rate is maintained even after up to 40 weeks off drug. The early studies suggested that Chantix may result in higher quit rates than other pharmacological treatments for smoking. Whether this ultimately turns out to be the case will require additional studies directly comparing different treatments.

The take-home message for smokers interested in trying to quit is that this new medicine continues to demonstrate that it is safe and effective in increasing smokers’ chances of successfully quitting, with the most frequent side-effect being mild nausea (16-42% of users). The nausea is less marked at lower doses, and also appears less when taking the pill along with food and water. Most people using Chantix are able to continue using it and the initial nausea subsides. Those continuing to take Chantix for the full course (up to 24 weeks) tend to have higher quit rates than those discontinuing early.

Labels: addiction, cessation, Chantix, cigarette smoking, nicotine, tobacco, varenicline

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Chantix and mental illness - what are the facts?

The August issue of the American Journal of Psychiatry included two letters reporting single cases of worsening of symptoms of schizophrenia and mania, while they were taking the new smoking cessation medication, Chantix (varenicline). Links to those case reports can be found below. It was also noticeable that some readers of my previous article on Chantix who were also taking medications for psychiatric problems wrote online comments about unpleasant side effects.
http://www.healthline.com/blogs/smoking_cessation/2007/04/chantix-how-does-this-new-quit-smoking.html

People suffering from major mental illnesses were excluded from the initial placebo-controlled trials of varenicline (Chantix), which showed that it is both safe and effective in helping smokers to quit. It is normal practice to exclude certain categories of patient from trials of new medicines, prior to the drug being approved for sale to the public. Often the reason is that patients with certain diagnoses are more likely to be taking medications that may affect the condition being treated (e.g. antidepressants could theoretically affect smoking cessation, as at least 2 antidepressants are effective for smoking cessation). Sometimes it is partly to protect those considered “at risk”, from taking an unlicensed experimental medicine. What we end up with is that many new medicines have mainly been studied in people who are relatively healthy, apart from having the condition the new medicine is designed to treat. Chantix is like many new drugs in this respect. It is also very common, especially for new medicines that are very widely used, for reports to appear of unusual side-effects occurring in some patients. I’ve published a few such reports myself.

However, it is not until fairly thorough additional placebo-controlled studies have been published in more patient groups, that we can tell with any confidence whether the new drug really does cause problematic side effects in certain patient groups or not. Sometimes such studies are never carried out and in that case we need to rely on the reported experiences of clinicians treating those patient groups over a period of time.

One thing we have to bear in mind is that when a person starts using Chantix, that’s not the only thing that’s changing. That person will also be trying to quit smoking. Quitting smoking itself causes a number of changes, including the increases in nicotine withdrawal symptoms I’ve talked about before (see link below), and also a slowing in metabolism of some medications, that could cause an increase in the blood levels of the drugs contained in those medicines (I’ll discuss this in a future post). So some symptoms may be related to quitting smoking, rather than Chantix per se.

So if I had a relative who smoked and suffered from a mental illness (like schizophrenia, bipolar disorder or depression) and was taking medicine for that illness but wanted help to quit smoking, what would I suggest?

As with all the people I see who want to quit smoking, I’d describe all the available forms of help, including counseling, internet support and medicines. I’d recommend that they use these. With regards to medicines, I’d point out one advantage of nicotine replacement therapy, which is that it does not involve taking a “new” drug, - as they have been taking nicotine in a much more harmful form every day, for years. When discussing Chantix I’d point out that it had not been studied in many people with a serious mental health problem, and so it would be particularly important to discuss that option with their doctor and to allow the doctor to monitor their progress on that medicine fairly closely if the doctor decided to prescribe it. But if my family member had already tried nicotine replacement therapy and wanted to try something different, I wouldn’t discourage it. I’ve heard from many clinicians who have treated patients with mental health problems successfully with Chantix, and so I am not convinced yet that there is a markedly increased risk of adverse events caused by Chantix in such patients.

It would be helpful to hear peoples’ experiences of using Chantix, particularly if you have also had a mental health problem. If you feel that any medicine has caused a harmful effect, then you should tell your doctor, and particularly in the case of a new medicine, it may be appropriate to report this to the FDA. For further information on that procedure, visit: http://www.fda.gov/medwatch/

Here are the links to the recent case reports:
http://ajp.psychiatryonline.org/cgi/content/full/164/8/1269
http://ajp.psychiatryonline.org/cgi/content/full/164/8/1269-a

Here is the link to my previous article on nicotine withdrawal:http://www.healthline.com/blogs/smoking_cessation/2007/03/what-is-nicotine-withdrawal-syndrome.html

Labels: Chantix, mental illness, quit smoking cessation tobacco advice cigarettes, Smoking, tobacco, varenicline

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Make yours a smoke-free home

My previous two posts focused on the harmful effects of exposure to tobacco smoke pollution (ETS or SHS). It is clear that inhaling air contaminated by smoke from other people’s tobacco smoke can harm your health. As always, the risk is related to the cumulative dose and so the riskiest places are those in which we spend most time. The primary reason for legislation banning smoking in public places is actually to protect the people for whom that place is their workplace. While it could be argued that spending a couple of hours in a restaurant where someone else has smoked is unlikely to cause you a serious illness (notwithstanding the fact that some people can have asthma attacks or other illnesses triggered by relatively brief exposure), there is no doubt that a waitress spending forty or more hours in that environment every week will have a significant risk of contracting a serious illness caused by the smoke exposure. So the case for protecting workers in bars, restaurants, casinos and all other workplaces from tobacco smoke pollution is very clear and very strong.

Of course, other than the workplace, the other place we spend most time is our home. The home is also the place that children spend most of their time. Largely for these reasons, more and more households are deciding to be smoke-free as well. The proportion of households with smoke-free home rules in the United States ("No one is allowed to smoke anywhere inside your home,") increased significantly, from 43% during 1992--1993 to 72% in 2003. In 2003, 32% of households with a smoker living there had a smoke-free rule, as compared with 72% of households with no resident smokers.

So it is now the norm in the United States for a household to have a policy that no-one smokes indoors, and around a third of households with smokers were already implementing such a rule in 2003. The reasons are clear:
- tobacco smoke contains thousands of toxins.
- the concentration of some of these toxins in the air increases over time
- it is clear that exposure to tobacco smoke pollution increases the risk of serious illnesses
- smokers who live in smoke-free households are more likely to quit
- in addition, allowing smoking in the house increases the risk that children will be exposed and may become smokers themselves

So if you live in a household without any smokers, but without a smoke-free policy, its time to sit down with the family and agree on having one. and how it will be implemented on occasions when people may want to smoke (a houseparty, a home-repair worker, a visiting family-member who smokes etc).

Likewise, if you live with a smoker and currently allow smoking in the home, perhaps its time to make a change. Most smokers nowadays are aware of at least some of the effects of tobacco smoke pollution and therefore understand the rationale for having a smoke-free home and car. Most of the year it is no great hardship for the smoker to do their smoking outside. Sitting down with the people you live with and providing a heartfelt reason for making the household smoke-free may not meet with as much resistance as you might think.

Helpful information on smoke-free homes is available at:
http://www.epa.gov/smokefre/pledge/

Further information including smoke-free cars can be found at:
http://www.smokefreezone.org/

The latest data on the proportion of smoke-free homes in the United States can be found at: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5620a3.htm

Labels: ETS, nicotine addiction cigarette, pollution, SHS, smoking tobacco

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Sidestream cigarette smoke more toxic than mainstream smoke

In my last post about tobacco smoke pollution I mentioned the puzzling fact that although exposure to tobacco smoke pollution (TSP or ETS or SHS) gives about 1-5% of the smoke dose of active smoking, it gives a proportionately bigger increase in some disease risks. This fact has caused some to be rather skeptical about the evidence on tobacco smoke pollution and health. But just this month a new paper has been published by Drs Suzaynn Schick and Stan Glanz at University of California at San Francisco, that sheds some new light on this.

One of the main carcinogens in cigarette smoke is known as NNK (as its long chemical name is almost unpronounceable!). Previous studies have shown that there is a 3-4 times higher concentration of NNK in sidestream smoke (the smoke released from a burning cigarette into the air between puffs) than in mainstream smoke (the smoke inhaled by the smoker). But the new paper by Drs Schick and Glanz went further. They analyzed tobacco industry documents dating back to the 1980s that showed that Philip Morris tobacco company (which was, at that time, denying the harmfulness of exposure to environmental tobacco smoke) had conducted studies that not only measured these effects, but uncovered the mechanism behind it (continued reaction of nicotine, nitrogen oxides and other smoke chemicals). These studies also showed that while the smoke ages as it hangs in the air in a room where someone has smoked, the concentration of NNK actually increases another 2-4 times! So the net effect is that the concentration of NNK per unit of sidestream smoke hanging around in the air in a room hours after the smoker has left, may be 10 times greater than the concentration per unit of smoke the smoker inhaled directly from the cigarette. This type of finding may be a part of the explanation of why exposure to tobacco smoke pollution is more harmful than we might expect from the simple amount of smoke being inhaled.

Of course the tobacco company that discovered these results (Philip Morris, makers of Marlboro) did not expend much effort to share them with the public. Rather, it has taken painstaking research by public health scientists to piece together the evidence from tobacco industry documents and publish them in a peer-reviewed journal.

This gives yet more reason to ensure that people (and pets) in public spaces should not be exposed to tobacco smoke pollution, and to make sure your home environment is smoke-free.

This link takes you to the original journal report:
http://cebp.aacrjournals.org/cgi/content/abstract/16/8/1547

Labels: ETS, pollution, SHS, Smoking, tobaco

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Health effects of Tobacco Smoke Pollution

Tobacco smoke pollution (TSP), also known as, “environmental tobacco smoke (ETS)” or “secondhand smoke (SHS)” is the tobacco smoke that enters the environment as a result of (a) sidestream smoke, that comes directly from the burning tip of the tobacco product without having been exhaled by the smoker and (b) mainstream smoke, that has been exhaled by the smoker.

As tobacco smoke is one of the most potent toxic compounds, tobacco smoke pollution can impact on many health problems, even at low levels of exposure. It is estimated that at least 50,000 deaths are attributable to second hand smoke each year in the United States (California Air Resources Board, [CAR] 2005). The list below contains some of the most common health effects of that have been causally linked to TSP.

Developmental Effects
Low birthweight
Sudden Infant Death Syndrome (SIDS)
Pre-term delivery

Respiratory Effects
Acute lower respiratory tract infections in children (e.g., bronchitis and pneumonia)
Asthma induction and exacerbation in children and adults
Chronic respiratory symptoms in children
Middle ear infections in children

Carcinogenic Effects
Lung cancer
Nasal sinus cancer
Breast cancer in younger, primarily pre-menopausal women

Cardiovascular Effects
Coronary artery disease

With cardiovascular diseases being associated with a very high proportion of overall deaths, factors that increase risk of cardiovascular mortality have a substantial societal impact. TSP results in smoke exposure of about 1% of typical active smoking, but increases cardiovascular risk by 30%. Recent evidence suggests that policy regarding TSP can have substantial effects on cardiovascular events. A study conducted in Helena, Montana found that implementation of a comprehensive local ordinance on clean air was related to a 40% reduction in admissions for acute myocardial infarction, which subsequently rebounded after the ordinance was suspended (Sargent, Shephard, Glantz, 2004). This study demonstrates the potential health benefit of establishing smoke-free environments.

It has been demonstrated that non-smokers have statistically greater risk of lung cancer if their spouses are smokers. Meta-analyses show the increased risk of lung cancer was about 25% greater than expected in women and 35% greater in men if their spouses smoked (National Cancer Institute, 1999).

So what can you do to avoid exposure to Tobacco Smoke Pollution? Firstly, if you live in a state that has yet to implement legislation requiring public places to be smoke-free, then make a point of only going to bars and restaurants that are smoke-free and let the owner know how much you appreciate it. Each state produces a list of smoke-free venues.
Secondly, while you can’t necessarily control every environment, one important environment that you may be able to control is your own home. So make sure that you and your family are not exposed to toxic tobacco smoke pollution at home by making your home a Smoke-Free Home. I’ll talk more about smoke-free homes in my next post.

For an extremely comprehensive report on the effects of Tobacco Smoke Pollution, see the 2006 report launched by Surgeon General Carmona (now a member of the board here at Healthline). http://www.surgeongeneral.gov/library/secondhandsmoke/

For an interesting report on the effects on heart attack rates when a city in Montana passed smoke-free environment legislation (plus a commentary by CDC) see:
http://www.bmj.com/cgi/content/full/328/7446/977?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=helena+ets&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT

Labels: ETS, nicotine addiction cigarette smoking tobacco, nicotine regulation reduction smoking smokeless, pollution, SHS

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Menthol smokers inhale more toxins

A new study published this month in the journal, Nicotine & Tobacco Research, has found that people who smoke menthol cigarettes have higher levels of blood nicotine, cotinine (main nicotine metabolite) and higher levels of exhaled carbon-monoxide.

The original study, led by Dr Jill Williams of the University of Medicine and Dentistry of New Jersey, was actually designed to assess whether people who suffer from schizophrenia inhale more nicotine from their cigarettes than people not suffering from schizophrenia. Dr Williams, one of the nation’s top experts on smoking and mental health, found that people with schizophrenia inhale about 30% more nicotine from their cigarettes (as indicated by biochemical measures). After we noticed that quit rates were significantly lower among smokers of mentholated cigarettes at the Tobacco Dependence Clinic at UMDNJ-School of Public Health, Dr Williams and colleagues re-analyzed the data from the schizophrenia study, which included data on the type of cigarettes smoked by participants. The finding of higher nicotine and cotinine levels among smokers of menthol cigarettes is not entirely new. But previous research was unclear on whether this reflected different metabolism of nicotine by menthol smokers, or increased inhalation of smoke by menthol smokers (or both). The finding of increased levels of carbon-monoxide points to increased smoke inhalation by menthol smokers.

So why would menthol smokers inhale more smoke? Note that this study took place in New Jersey, the state with the highest cigarette taxes ($2.58 state tax plus 39c federal tax per pack). So smokers on low incomes have been forced to reduce their cigarettes per day as a financial necessity. The natural reaction of the nicotine addict to smoking fewer cigarettes per day is to inhale more nicotine (and smoke) per cigarette to try to get the usual dose. However, with regular cigarettes the attempt to inhale larger puffs is limited by harsh sensations on the throat. However, with menthol cigarettes, larger puffs deliver larger doses of menthol which cools the harshness by stimulating cold receptors, and facilitates increased inhalation.

At first thought this could sound like a good thing to the heavy smoker. But it appears to lead to increased addictiveness (lower quit rates) and also may be a part explanation for the much higher death rates from lung cancer among smokers from racial groups that predominantly smoke menthols (e.g. African Americans and Native Hawaiians). It is noticeable that the tobacco industry targets its marketing of menthol brands towards groups who typically have less cash to spend (e.g. young people and ethnic/racial minorities). Perhaps the industry has figured that the menthol brands can get those groups “hooked” on a lower daily cigarette consumption?

To view a TV news item that includes coverage of this issue, visit:
www.tobaccoprogram.org

To view the full text/pdf of a study reporting lower initial quit rates among menthol smokers (Foulds et al, 2006. Factors associated with quitting smoking…) and a number of other studies, visit: http://www.tobaccoprogram.org/staffarticles.htm

To learn more about quitting smoking while coping with a mental illness, visit:
http://www.njchoices.org/index.htm

Labels: carbon monoxide, cigarette, lung cancer, menthol, nicotine, schizophrenia

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Thank you Health Business Blog for grand rounds 3:45.

Thank you to David E. Williams of Health Business Blog for hosting Grand Rounds this week and including my posting on Health Insurance Coverage for Nicotine Dependence (plus a review of Michael Moore’s “Sicko”) . Grand Rounds is a compilation of blogs from all across the medical blogosphere that is held once a week. Its worth paying a visit to his site:www.healthbusinessblog.com/?p=1370

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