What proportion of smokers become addicted?

Most people who become smokers initiate smoking before the age of 18. They generally try smoking as part of experimentation, after observing their peers and family smoking and viewing tobacco advertising. It is fairly natural, when cigarette smoking can be observed so widely, for a child to think, “I wonder what that is like?”. Most kids who try smoking are not considering or expecting that they may become addicted. But it may be worth educating young people on their risks of becoming addicted. To do so we have to be clear about what we mean by “addiction”.

Nowadays the words “dependence” and “addiction” are generally used interchangeably with the same meaning. When used in relation to substance or drug use, these words refer to a situation in which the drug has come to unreasonably control a person’s behavior. The central characteristic of most definitions of drug addiction is that the individual experiences an impaired ability to reduce or end their use of the drug. In the case of cigarette smoking that characteristic is most commonly expressed as long term daily smoking despite awareness of the likelihood of serious health effects, a desire to reduce or quit, and failed attempts to reduce or quit.

In order to more clearly define, diagnose and study nicotine dependence, various diagnostic criteria have been developed, such as those of the American Psychiatric Association (DSM-IV) or the World Health Organization (ICD-10). These typically describe a list of criteria and require individuals to meet a certain number of these to meet the diagnostic threshold for “nicotine dependence”. There are 7 main DSM-IV criteria, (including things like difficulty cutting down, continued use despite it causing problems, experience of withdrawal symptoms when reducing etc) and if a smoker meets at least 3 of these they are considered to be “nicotine dependent”. Of course there is a certain artificiality about this because most people consider that nicotine addiction exists on a continuum of severity, rather than being a categorical disorder that a person either does or does not have. But these diagnostic frameworks at least give us a way of identifying those who are clearly addicted.

Last year, Drs Eric Donny and Lisa Dierker published a paper (in the journal, “Drug and Alcohol Dependence”) that aimed to identify what proportion of smokers in the general population met strict DSM-IV criteria for nicotine dependence. Their study was based on direct interviews with a large, representative sample of non-institutionalized adults in the United States in 2001-2. From that sample they focused on the 8,213 who were daily smokers in the past year. This sample included people who smoked anything from 1 to over 40 cigarettes per day, and people who had smoked for less than one to over 50 years.

The study found, not surprisingly, that the greater the number of cigarettes per day the person smoked, the greater the chance that they would meet strict diagnostic criteria for having become nicotine dependent. Whereas under 50% of those who smoked 1-5 cigarettes per day met the criteria, over 80% of those who smoked over 30 cigarettes per day met the criteria.

Unexpectedly, however, the longer the person had smoked, the less likely they were to have become dependent, particularly if the person had started smoking over 50 years ago. This finding seems very odd, and may have more to do with memory for quit attempts or attitudes to smoking among older age cohorts.

Overall, over 60% of ever daily smokers met strict diagnostic criteria for having become nicotine dependent. But almost all smokers had experienced at least one symptom of nicotine dependence. For example, 97% of “dependent” smokers had experienced difficulty cutting down their cigarette consumption, as had 72% of “non-dependent” smokers. The authors acknowledged that the differences in dependence between these two groups may be more quantitative rather than qualitative. The authors also acknowledged that certain co-occurring factors appear to make it more likely that a smoker will bcome dependent. An example they provided was a history of major depression, which is associated with approximately 100% nicotine dependence among heavy smokers.

So we can tell young people that if they take up smoking, there is an over 90% chance that they will experience some symptoms of nicotine addiction, and over a 60% chance that they will go on to meet strict diagnostic criteria for becoming addicted to nicotine.

A pdf copy of the full paper by Drs Donny and Dierner can be accessed (near the bottom of the page) at:
http://www.tern.org/Publications.htm

Labels: addiction, cigarette, cigarette smoking, dependence, jonathan foulds, nicotine

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Can cigarettes be made less deadly?

Since it became clear in the 1950s and 60s that cigarettes are deadly when used as intended, there have been various attempts to make them less harmful. These have included the addition of and modifications to filters, and changes in the type of tobacco used. But none of these changes has made a great deal of difference. Part of the problem is that changes that reduce the amount of one toxin often have an opposite effect on the amounts of other toxins in the smoke. Another problem is that changes to the product can affect the way it is used by consumers. The most obvious example here is that as the amount of nicotine in the tobacco decreases, so the smoker takes larger puff volumes in order to get their usual dose. The main lesson from all this is that when humans take any product, burn it, and inhale the smoke into their lungs, it is inevitably going to be very harmful to that individual’s health. Our bodies did not evolve to inhale smoke.

It is partly for this reason that I take the view that the tobacco industry should be given the strongest encouragement to move out of the smoking business entirely, and focus on smokeless tobacco as a way of making money out of nicotine addiction.

However, it’s a reality that cigarettes will be around for the foreseeable future and therefore it makes sense to try to make them less harmful. This month an influential report was published on this topic in the journal, “Tobacco Control” by a World Health Organization study group. The group (called TobReg) proposed a mandated lowering of of permissible toxicants in cigarette smoke. They took the 9 main toxicants, examined the range of levels of these toxicants emitted by international cigarette brands (and there are very wide ranges) and recommended that all cigarettes must emit an amount less than approximately the current median level found in a range of brands. This is analogous to measuring the amount of pollutants emitted by all of the new cars in the world today, and then saying that from some future point in time, all new cars must emit an amount of pollution less than the car that ranks in the middle of the current range. Clearly the standard can be tightened again in the future.

This would mean that for each toxicant, about half of the existing brands would require modification in order to comply with the standard. It means that for 9 toxicants, a far larger proportion of current brands would need to be modified in order to be fully compliant for all 9 toxicants. It should be noted that the toxicant concentrations are expressed in units per milligram of nicotine. This is a wise way to do it, which recognizes that smokers smoke for nicotine, and that it is the ratio of toxins to nicotine that is therefore important. The rationale and many complex details of the proposal are described in the report, which can be accessed for free at:
http://tobaccocontrol.bmj.com/cgi/content/full/17/2/132
A commentary can also be viewed at:
http://tobaccocontrol.bmj.com/cgi/content/full/17/2/73

These proposals are a sensible first step at making cigarettes a bit less harmful. Surprisingly there is even a chance they could be accepted by a major tobacco company. Philip Morris (now split into a separate US and a separate “international” company) may consider that despite all the hassle in complying with such regulations, they may come out smelling of roses (i.e. smelling of money) because they are in a stronger position to make the required technical changes than many smaller companies. They therefore may consider that the regulations present an opportunity for them to gain market share via more efficient regulatory compliance.

It is interesting that the approach taken in this report is almost the opposite of that which has been proposed in the United States, which involves leaving all the toxicant levels as they are, but reducing the nicotine delivery down to levels that will no longer be addictive.

I continue to believe that while both of these approaches have merit, the most direct route for the tobacco industry to stay in business but causing much less harm to health, is for it to be required to focus exclusively on smokeless tobacco products. These have already been shown to be consumer-acceptable, deliver adequate doses of nicotine, but cause far lower levels if ill-health (e.g. no lung cancer or COPD). This approach also avoids the challenging task of enforcing at the individual level. If I’m a policeman walking down the street and I see someone smoking, it is impossible to tell if that cigarette complies with the reduced nicotine or reduced toxicant regulation. If cigarettes are outlawed and only smokeless products are allowed, then enforcement is much simpler.

For smokers, it is important not to sit back and wait for these less harmful cigarettes to come along. This is a long-term project that has only just been proposed. It is highly likely that you will have died of a serious smoking-caused disease long before these proposals result in meaningfully less harmful cigarettes. So the main message remains the same:

The single best thing you can do for your health is to stop smoking completely. There are now a range of effective methods (e.g. quitlines, internet sites, etc) and medicines available that can help you to successfully quit smoking, and you should talk to your healthcare professional about which ones would suit you.

Labels: cigarette, cigarette smoking, jonathan foulds, nicotine addiction, tobacco

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What is in cigarette smoke?

More than 4000 different chemicals have been identified in cigarette smoke. Most of us have a very basic idea that these chemicals can be harmful to health and that the mechanisms whereby this complex mixture of toxins contained in tobacco smoke leads to specific diseases are complex. However, I thought it might be helpful to some readers to provide a very basic description of the ways in which some of these components of cigarette smoke cause ill-health.

The simplest categorization of the components if cigarette smoking identifies 3 major components: tar, nicotine, and cabon-monoxide (CO).

Tar is the black sticky mass that coats the lungs and the airways. There are many hundreds of different chemicals within the tar, some of which have been shown to be carcinogenic in animals and/or humans. The deposition of particles of tar in the lungs and upper airways leads to the blocking of airways and to serious breathing problems, including Chronic Obstructive Pulmonary Disease (COPD). The toxic chemicals also cause inflammation and reduce the elasticity of the lungs and hence the ability to inhale and exhale normally.

The carbon-monoxide in smoke replaces oxygen in the hemoglobin (a component of blood), adversely affecting oxygen transport and energy supply, and requiring the heart to do more work to supply the same amount of oxygen to the body. A large number of smoke constituents, and particularly components of the gaseous phase of the tobacco smoke, cause immunologic responses and inflammation in the cells. This causes increased stickiness of the blood which increases the risk of clots. These processes increase the likelihood of a heart attack, stroke or other problems with the cardiovascular system.

Irritants such as nitric oxide cause hypersecretion of mucus and substances such as acrolein, acetone and acetaldehyde cause damage to the small hair-like strands that line the airways (cilia). This damage to the cilia impairs the ability of the cilia to clear mucus, causing breathi9ng difficulties. Years of smoking and daily coating of the lungs and airways in tar leads to irreversible lung damage and ultimately death from COPD .

Acute nicotine (critical for the development of addiction), increases heart rate, blood pressure and causes peripheral vasoconstriction (i.e. impairs peripheral circulation and thus exacerbates Reynauds’ Disease and erectile dysfunction). However, studies of smokeless tobacco users (who have high nicotine exposure like smokers, but without the smoke) compared with smokers, suggest that most of the cardiovascular problems are not caused by nicotine. It therefore appears that it is the thrombogenic effects of tobacco smoke exposure (primarily oxidant gases), combined with reduced oxygen supply (carbon monoxide) and increased myocardial oxygen demand (nicotine) that cause the cardiovascular harms from smoking.

Some of the chemicals found in cigarette smoke are listed below.

Carbonyls
Formaldehyde, Acetaldehyde, Acetone, Acrolein, Propionaldehyde, Crotonaldehyde, Methyl-Ethyl-Ketone, Butyraldehyde
Phenolics
Hydroquinone, Resorcinol, Catechol, Phenol, Cresol (m+p and o)
Aromatic Amines
3- and 4-aminobiphenyl, 1- and 2- aminonapthlene, o-toluidine, o-anisidine
Oxides of Nitrogen NO,
Hydrogen Cyanide
Ammonia
Volatiles
Benzene, Toluene, 1,3-butadiene, Isoprene, Acrylonitrile
Semi-Volatiles
Pyridine, Quinoline, Styrene
Trace Metals
Nickel (Ni), Cadmium (Cd) Lead (Pb) Chromium (Cr) Arsenic (As) Selenium (Se), Mercury (Hg)
Tobacco Specific Nitrosamines
N-Nitrosonornicotine (NNN)N-Nitrosoanabasine (NAB) Nitrosoanatabine (NAT)4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK)
Volatile Nitrosamines
N,N-Nitrosodimethylamine (NDMA)N-Nitrosopyrrolidine (NPYR), N,N-Nitrosodiethylamine (NDEA)N,N-Nitrosoethylmethylamine (NEMA), N,N-Nitrosodipropylamine (NDPA)N,N-Nitrosodibuthylamine (NDBA), N-Nitrosopiperidine (NPIP)
Polycyclic Aromatic Hydrocarbons
Naphthalene, 1-Methylnaphthalene, 2-methylnaphthalene, AcenaphthyleneAcenaphthene, Fluorene, Phenanthrene, Anthracene, FluoranthenePyrene, Benzo(a)anthracene, Chrysene, Benzo(b)fluorantheneBenzo(k)fluoranthene, Benzo(j)fluoranthene, Benzo(g,h,l)peryleneBenzo(e)pyrene, Benzo(a)pyrene, PeryleneIndeno(1,2,3,-cd)pyrene, Dibenzo(a,h)anthraceneDibenz(a,j)acridine, Dibenz(a,h)acridine, Dibenz(a,e)pyreneDibenz(a,h)pyrene, Dibenz(a,i)pyrene, Dibenz(a,l)pyrene7H-Dibenzo(c,g)carbazole,
Heterocyclic Aromatic Amines
2-Amino-3-methylimidaszo(4,5-f)quinoline (IQ)2-Amino-3,4-dimethylimidazo(4,5-f)quinoline (MeIQ)2-Amino-3-methyl-9H-pyrido(2,3-b)indole (MeAaC)2-Amino-9H-pyrido(2,3-b)indole (AaC)1-Methyl-9H-pyridol(3,4-b)indole (Harman)9H-Pyrido(3,4-b)indole (Norharman)

Labels: cancer, chemicals, cigarette, jonathan foulds, nicotine, smoke, tar, toxins

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One Cigarette Wouldn’t Do Any Harm – Would It?

Just over half of the “ever-smokers” (those who ever became regular smokers) in the United States are now “ex-smokers”. Of course for all ex-smokers, the possibility of relapse is real, and the shorter the time since your last smoke the greater the risk of going back. As many as 40% of those who go a whole year without a smoke will lapse and have another cigarette or more in the next few years, while for those who havn’t smoked for five years or more the chances of going back to smoking are much lower.

I suspect that most visitors to the Healthline.com website are not current smokers, but that a sizeable proportion will be ex-smokers, many of whom gave up long ago (5 years or more). Most long-term ex-smokers are very happy and relieved to have successfully quit, but many will admit to getting occasional urges to smoke. Being in situations where you previously smoked (e.g. a bar) or doing an activity that was associated with smoking (e.g. walking the dog) or even just being in a certain mood state can trigger thoughts about smoking, even if you hadn’t thought about it at all for weeks or months. On many of these occasions you won’t have any tobacco available and the thought will pass in a matter of a few seconds. But certain things seem to be associated with stronger cravings and relapse risks. Some of these things are very obvious practical factors, such as the availability of cigarettes. Some are factors that serve to lower our inhibitions or lead us to believe that we “deserve” a smoke (e.g. drinking alcohol, being at a celebration or being on vacation). Even though alcohol can trigger cravings directly, sometimes I suspect that consuming alcohol also causes an indirect effect whereby the ex-smoker believes that being intoxicated somehow gives them an acceptable excuse.

One other psychological factor that increases relapse risk is the thought that, “one cigarette won’t do any harm.” This type of thought is very seductive because on the surface it may seem like a very reasonable point. One cigarette on its own is very unlikely to trigger a serious illness. Ex-smokers entertaining this train of thought often find themselves thinking further rationalizing thoughts such as, “and if I hang out in that smoky bar all evening I’ll probably breath in a whole cigarette’s worth of smoke just from other people’s smoke…so whats the difference?”. But the important thing to remember is that the biggest risk from smoking a single cigarette, is that it greatly increases the risks that you will smoke another and then another and so on. We don’t fully understand the mechanism for this type of relapse but some of it likely occurs at a neurobiological level. Even laboratory rats that have learned to press a lever for nicotine may get a sudden reinstatement of bar pressing if they are given a single injection of nicotine. But there is also a cognitive component to it, that is referred to as the “abstinence violation effect”. This is the process whereby an ex- smoker who has a lapse cigarette then finds him/herself thinking, “oh well, I’ve broken my good record now…I may as well finish the pack” (something that the lab. rat probably doesn’t think).

So it is far better to be very clear in your mind that one cigarette could do a great deal of harm, (by prompting a return to pack-a-day smoking) and that “not-a-puff” abstinence is the way to go.

Labels: cigarette, relapse, smoking cessation

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State-specific prevalence of cigarette smoking.

In previous posts I’ve discussed international differences in tobacco use, which showed that by international standards, male cigarette smoking prevalence is relatively low in the United States, but female smoking prevalence is higher in the US than most other parts of the world. The clearest contrast is with a countries like China, where almost two-thirds of men smoke, but only a few percent of women smoke.

On Friday (Sept 28th, 2007) the US Centers for Disease Control published the latest (2006) figures for adult cigarette smoking prevalence within each U.S. state. The median prevalence was 20.2%, but consistent with recent years, there were some large between-state differences. The highest smoking rates were in tobacco-growing states such as Kentucky (28.6%), or West Virginia (25.7%). The lowest smoking rates were in places with strong cultural prohibitions against tobacco such as Utah (9.8%) and California (14.9%).

Overall, the median smoking rates were higher for men (22.2%) than for women (18.5%). Although it is probably unwise to make too much of single-year prevalence estimates for relatively small geographic regions, such as individual states, I like to look at these to see if anything potentially interesting pops out. The California figures are always of interest as a guide to how low we can go in the rest of the United States. Although the low smoking rates in California are partly related to the high number of non-smoking immigrants to that state, they are largely due to California’s comprehensive tobacco control program that was the first to be reasonably well funded, to increase cigarette taxes, and to pass legislation requiring smoke-free indoor public places. The California program also used a hard hitting media campaign to publicize the harmfulness of tobacco smoke (including to non-smokers), and to encourage smokers to try to quit.

Kentucky provides us with a good example of what happens in a state where the tobacco industry dominates the political agenda – you get very weak tobacco control and very high smoking rates. One thing that stood out was the low smoking rate in Idaho (16.8%). I must say I have no idea why Idaho’s smoking rates are so low, but would be grateful if someone could tell me! The other odd thing I noticed was that despite the fact that men generally smoke more than women, in two states that wasn’t the case. In West Virginia 25.4% of men smoke cigarettes and 26% of women smoke them, and in Montana 18.5% of men smoke as do 19.6% of women. The very high female smoking rate in W.V. may just be a blip in the data, (?) but the Montana difference looks to be related to unusually low male smoking rates in that state. The only other part of the world where the proportion of men who smoke is consistently lower than women is Sweden, and in that case it is because many men have switched from smoking to snuff (smokeless) tobacco. If anyone out there has an explanation for the male/female smoking pattern in Montana and West Virginia I’d be interested to hear it.

If you would like to find out the latest figures for your own state, check them out via this link: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5638a2.htm

Labels: cigarette, cigarette smoking, prevalence

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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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Could smoking reduction improve your health?

Although around 70% of smokers say they would like to quit smoking, many are not planning to try to quit within the next six months. A sizeable minority are more attracted to the idea of reducing smoking rather than quitting altogether. It is also true that with increases in the cost of cigarettes and restrictions on smoking in public places, many smokers are having to reduce their smoking, whether they like it or not.

However, is there a health benefit from reducing the number of cigarettes smoked? Now this may sound like a silly question. Most of us are aware that there is a clear “dose-response” relationship between the number of cigarettes smoked and the risk of suffering from a disease such as lung cancer. But we must remember that most of the people in these studies were smokers smoking at their natural rate. A person who has always smoked 10 cigarettes per day may not be like someone who smoked 20 per day and then reduced to 10 per day. One of the effects we know about is that people who cut down their daily consumption tend to increase the amount they inhale from each cigarette. In fact it is not difficult to suck two or three times as much smoke out of a cigarette by simply inhaling more deeply and taking more puffs per cigarette. Clearly if someone inhaled twice as much smoke out of each cigarette we would not expect any health benefit from cutting the number of cigarettes per day in half.

Last month, Professors Charlotta Pisinger and Nina Godtfredsen from Denmark published a comprehensive review of the medical literature on the health effects of reduced smoking (in the journal, “Nicotine & Tobacco Research”). They defined smoking reduction as reducing the number of cigarettes per day by at least 50%. Overall, they found that such a reduction may improve some respiratory symptoms, and may reduce lung cancer risks. However, on some of the “harder” outcome measures, such as performance on lung function tests, there was no improvement from reduced smoking. Perhaps most importantly, in the largest study that looked at effects on mortality, people who cut down by 50% and maintained it over 15 years were just as likely to die early as those who didn’t cut down, and of course both groups had much higher death rates than those who quit smoking.

So overall, the data suggests that the health benefits of reduced smoking are much smaller than one might expect or hope for. It is also important to recognize that most smokers find it very difficult to reduce by much more than 50% and then maintain the lower level for a long period. When stressful life events occur, there’s a strong tendency to return to the old level of smoking. It suggests to me that it makes much more sense to make a firm plan to quit smoking altogether. If something is causing you to hesitate about quitting completely on one day, then by all means make a plan to reduce prior to quitting. But its important that your reduction has a plan (i.e. a date) by which you will reach zero cigarettes per day and keep it at that. The evidence is absolutely clear that quitting smoking results in substantial health benefits, as summarized in previous posts.
http://www.healthline.com/blogs/smoking_cessation/2007/02/how-bad-is-smoking-for-health.html

Labels: cigarette, health, nicotine addiction cigarette smoking tobacco, nicotine regulation reduction smoking smokeless

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Tobacco Use Around The World

A reader from Australia requested some comparative information on tobacco use around the world. By far the best source of such information is a superb book called, “The Tobacco Atlas” (2nd Edition) written by Dr. Judith Mackay, Dr. Michael Eriksen, and Dr. Omar Shafey. Large parts of the book are available online via the link below, but I’ll try to summarize the parts I found most interesting.

The most striking thing is the enormity of it. Taking cigarettes alone, global cigarette production continues to increase dramatically, from 1,686 billion cigarettes in 1950 to 5,604 billion in 2002. The magnitude of tobacco consumption in Asia generally and China in particular is mind-boggling. More than 300 million men smoke in China (70% of men) – more than the entire population of the United States, and they consume 30% of the world’s cigarettes each year. The other striking factor is that in many countries in the world (particularly Asia, Africa and the Middle East) smoking is largely a male past-time, with male smoking rates about 10 times those in women.

Because of these marked sex differences in smoking in some countries, around a billion men smoke and around 250 million smoke around the world. It is largely the high smoking rates among women in North America and Europe that causes the overall smoking rates in these countries to be relatively high – in most other countries male smoking is higher but female smoking is much less common. In fact the only country in the world that has had consistently higher female than male cigarette smoking rates over the past 10 years is Sweden. Sweden has the lowest male smoking rates in Europe, and is the only member of the European Union that allows the sale of smokeless tobacco. More men now use smokeless tobacco than smoke in Sweden.

In countries like the UK, USA and Australia there is a clear linear relationship between smoking rates and education/socioeconomic status, with smoking rates being much higher in the poorest, least educated sections of society. However, it is not like that across the globe. For example, in southern European countries such as Greece, female university students are more likely to smoke than young women not attending university. Amazingly in some countries (e.g. Turkey and Bulgaria) the smoking rates are higher among health professionals than in the general population. In China 57% of male doctors smoke!

The China National Tobacco Corporation is the biggest tobacco company in the world, having a monopoly in China as part of the Chinese government, and therefore having about a third of the global tobacco market. Then there are 5 major multinational tobacco companies with significant global market shares: Altria (Philip Morris): 17.6%, British American Tobacco (15.1%), Japan Tobacco Inc (9.5% including recent take-over of Gallaher Group PLC), Imperial Tobacco Group (3.6%) and Altadis (2%). In 2004, Philip Morris sold $57 billion worth of cigarettes in over 160 countries. Interestingly, in 2003, 851 billion cigarettes were reported as being exported around the world but only 664 billion were reported as being imported. Unless we are exporting to aliens on another planet, almost 200 billion cigarettes went “missing” in the process!

And to return to our Australian colleague, in fact Australia is one of the world leaders in tobacco control, with an adult smoking prevalence of around 17.6% (as compared with around 26% in UK and around 22% in USA). I often hear Americans return from vacation in Europe commenting on how “everyone” smokes over there. However, it depends which part of the USA one lives in whether smoking rates are much lower. In Utah and California smoking rates are much lower than most countries in Europe, but in Nevada and Kentucky smoking rates are higher than in many European countries.

For those of you with an interest in global tobacco, I’d strongly recommend taking a look at The Tobacco Atlas.
http://www.cancer.org/docroot/AA/content/AA_2_5_9x_Tobacco_Atlas.asp

Labels: cigarette, consumption, global, international, nicotine, smoking tobacco

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Cigarette Brand Preferences: start young and focus on 3 brands.

When you look at the cigarette counter at a supermarket or even a chain pharmacy you will typically see a wall of cigarettes and advertising placards touting dozens of types of cigarettes. However, although there are actually hundreds of different brands, and at least 25 different brands that are widely available, sales of cigarettes focus very much on just a few brands.

This is particularly noticeable in children, for whom almost all the sales focus on just 3 brands (can you guess what they are?). The other thing that is very noticeable is how brand preferences vary dramatically by ethnic/racial groupings. A massive ongoing study run by University of Michigan called, “Monitoring the Future” has been tracking youth smoking and other substance use over many years and has produced some fascinating data. For example, it has found that 65% of white youth smokers smoke Marlboro (as do 60% of Latino and only 8% of African American youth smokers), whereas 75% of African American kids who smoke prefer Newport (a mentholated brand), which is smoked by only 12% of whites and 20% of Latino youth smokers. The only other brand with any recognition in 1998 was Camel, which was smoked by 9% of white youth smokers. The full breakdown as of 1998 can be seen at:
http://www.monitoringthefuture.org/data/tables/cigbrands/table1.html

These patterns persist in smokers aged 12 or over (including adults) in a national survey carried out in 2005, with whites and Latinos preferring Marlboro, and African Americans preferring Newport. The main (fairly small) differences in that study were increased market penetration among African Americans for the “Kool” brand (11%, also a menthol), and increased market share for “discount” brands (eg Doral and Basic). The most recent data can be found at: http://www.oas.samhsa.gov/2k7/cigBrands/cigBrands.htm

If you would like to know why brand preferences are concentrated in this way, then visiting the website: www.trinketsandtrash.org may give you a clue. This site contains a collection of tobacco advertising and memorabilia and is a good tool for tracking the activities of vector in this epidemic: the tobacco industry.

I’d be interested in hearing your reasons for your brand preferences and if any ads influenced you.

Labels: brand, Camel, cigarette, Marlboro, Newport, preferences, race

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Higher nicotine intake per cigarette by African American smokers: is it a menthol effect?.

There are some quite large differences in tobacco use between the different racial and ethnic groups in the United States. One of the most consistent findings is that African American and Latino smokers smoke fewer cigarettes per day than non-Latino whites. For example, in a large study reported by Dr Richard O’Connor and colleagues in the American Journal of Epidemiology, in daily smokers aged over 24 years, African American smokers averaged around 12 cigarettes per day, whereas non-Latino whites smoked an average of around 18 cigarettes per day. Mexican-Americans smoked only 8 or 9 cigarettes per day on average.

However, this study also included a measure of blood cotinine – the main metabolite of nicotine and a good index of total nicotine intake. African American smokers had much higher cotinine concentrations (253 ng/ml) than white/non Latino smokers (208 ng/ml) and Mexican American smokers (94 ng/ml). So the estimated cotinine per cigarette was much higher (33) for African Americans, than both non-Latino whites (15) or Mexican American smokers (17). While there is some evidence that these differences in cotinine levels may relate to metabolic differences, they also appear to be due to real differences in nicotine intake per cigarette, as indicated by higher levels of exhaled carbon-monoxide.

A similar pattern was recently reported among 900 young adult smokers (aged 18-26), among whom whites averaged over 15 cigarettes per day but African Americans, Latinos and Asian smokers averaged 10-11 cigarettes per day. However, African American smokers had blood cotinine levels that were much higher than other groups, and an average cotinine level per cigarette that was more than twice that of non-Latino whites.

Part of these differences in nicotine intake per cigarette may relate to differences in the types of cigarettes smoked by different subgroups. Around 80% of African American smokers smoke a mentholated brand of cigarettes, compared to 25% for non-Latino whites. Menthol stimulates cold receptors and so cools the harshness of cigarette smoke on the throat, enabling a larger inhalation per puff.

If African Americans are inhaling more nicotine per cigarette, this would suggest that they may have increased absorption of other toxic chemicals. The habitual intake of more nicotine from fewer cigarettes may also produce a stronger addiction to cigarettes. Further evidence that is consistent with this idea emerged last year in a paper published in the New England Journal of Medicine which reported a higher rate of lung cancer, and lower rate of “ex-smokers” among African American and Native Hawaiian smokers. Interestingly, Native Hawaiians also have a strong preference for mentholated brands (65-80%). Putting together all of the evidence on this leads me to believe that people who smoke menthol cigarettes are likely to inhale more smoke per cigarette, be more addicted, and be at greater risk of smoking-caused diseases (all other things being equal). These effects are likely to be more marked in people who have had to restrict their cigarette consumption due to the expense of cigarettes, restrictions on smoking in public places or other factors (e.g. those affecting young people, or pregnant smokers). It also seems likely that the tobacco industry has targeted their marketing of menthol brands at groups they perceive as having less disposable income, because the industry knows that menthol cigarettes can get the customer addicted on fewer cigarettes per day.

Labels: African American, cigarette, cotinine, menthol, nicotine, smoker

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Which nicotine replacement therapy?

Nicotine replacement therapy (NRT) is the name given to FDA-approved medicines containing nicotine that are used to reduce nicotine withdrawal symptoms and cravings and to help smokers quit. Currently there are 5 main types: patch, gum, lozenge, nasal spray and inhaler. These latter two (nasal spray and inhaler) are only available via prescription in the United States, although they are available over-the-counter in many other countries (e.g. UK).

Each type of NRT has its own advantages and disadvantages. The patch is by far the most commonly used NRT, largely because it is the easiest to use, requiring only a single patch application per day. Another advantage of the patch is that its side effects are usually mild – primarily mild skin irritation and itching. The main disadvantage is that there is nothing one can do with the patch to increase the dose when you feel the need for more nicotine.

The gum and the lozenge are broadly similar in terms of dose (each available in 2mg and 4mg formats) and route of administration. The main challenge facing the gum chewer is to adopt a “chew and park” style, such that you chew the gum a few times to release a peppery taste (nicotine) and then park it in the side of your mouth for a few minutes before chewing again. The labeling on the gum suggests that people who smoke less than 25 cigarettes per day should use 2mg (rather than 4mg) and the labeling on the lozenge states that those who don’t smoke within 30 minutes of waking in the morning should use the 2mg lozenge. In practice many clinicians have learned that this labeling (especially the gum) is a recipe for under-dosing and advise all but the lightest smokers to use the 4mg formulation of each product. To get a real benefit from these products you need to use enough. Most users only take 3 or 4 per day in response to cravings. You can get a far greater benefit by taking one per hour (to prevent cravings and withdrawal symptoms) plus another whenever you have a breakthrough craving.

I described the nicotine nasal spray in some detail a few days ago. It appears to be particularly helpful for heavy addicted smokers who are willing to persevere despite the initial nasal irritation. Make sure you have some Kleenex handy when you first try the spray. The initial doses sting and will make you sneeze. But, just as with smoking, you will get used to it within a few days, and within a week will probably like it!

The inhaler‘s main advantage is that it enables the smoker to continue with a similar hand/mouth habit, but it helps to gradually wean them off nicotine. The main thing to note is that one puff on a cigarette delivers a similar amount of nicotine to ten puffs on the inhaler. This means that in order to obtain a therapeutic dose, the ex-smoker has to be puffing on the nicotine inhaler almost all the time. We recommend puffing on the inhaler for 20 minutes out of ever waking hour. Again, people who get into that regular use habit early on tend to do very well with the inhaler.

Some years ago Professor Peter Hajek and colleagues at the University of London conducted a randomized trial comparing the nicotine patch, gum, nasal spray and inhaler. In practice they all had similar quit rates (around 20-25% complete abstinence 3 months later), although women did better on the inhaler than the gum and men were the opposite. Prior to their quit attempt, participants were shown videos describing each NRT and were then allowed to rate their preferences. They were each then randomly allocated to one product. This meant that some people were allocated the product that was their first preference, whereas most were not. However, at the end of the study the smoking cessation outcomes were similar for those receiving their preferred NRT versus those being randomly allocated to a less preferred NRT. Also, people came to prefer the product they were given after they had used it for a week.

One final thing to consider is that the products differ in the risk of inducing dependence. It is extremely rare for someone to have any difficulty coming off the patch (which typically have a built-in reduction plan, involving using smaller sized patches over 4 weeks). However, some people (about 5-10%) find themselves using the gum, inhaler or lozenge long term (i.e. over 3 months and possibly continuing for years). The nicotine nasal spray has the highest dependence potential, with around 10-15% of those who use it continuing use after 3 months. The risk of becoming dependent is related to the speed of nicotine delivery from the product (spray fastest, but still slower and lower dose than a cigarette, whereas the patch delivers nicotine very slowly). It also seems to be related to how addicted the person was to their cigarettes. Thus people who smoked over a pack a day and smoke within 30 minutes of waking in the morning (or wake at night to smoke) are more likely to become a long term user of their NRT product. However, in the placebo-controlled trials these were precisely the people who were much less likely to succeed in quitting if they received the placebo. The thing to remember here is that it is much better to be a long term user of an NRT product delivering only nicotine, than a continuing user of a product that delivers a higher dose of nicotine plus 4000 other toxic chemicals (i.e. a cigarette).

Recently a group of experts in the treatment of tobacco addiction got together to produce a consensus statement guiding consumers on the most effective ways to use NRT to help them quit smoking. You can find a copy of the paper and the summary (in both English and Spanish) at: http://proyectovidanofume.org/publication.htm

Labels: addiction, cigarette, nicotine, NRT, replacement, Smoking, therapy, tobacco

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Its time for pictorial warnings on cigarette packs.

Virtually everyone knows that smoking is bad for health. But smokers typically don’t give much thought to the effects on their own health until they have been smoking for years. They also tend to be less aware of effects other than lung cancer (e.g. cardiovascular effects, effects on reproductive health etc). Health warnings first appeared on the side of US cigarette packs in 1965, stating that, “Cigarette smoking may be hazardous to your health.” The labels on U.S. cigarettes have not changed since 1984 and appear in small black and white print on the side of cigarette packs. Can you remember what they say? (most people can’t).

Messages given in small print on the side of the pack clearly lack salience and persuasive power compared with more colorful, larger messaging placed on the front of the packs. An expert panel commissioned by the National Academy of Sciences described the current warnings as “woefully deficient.” In an effort to help smokers be more clear about the health effects of cigarettes, many other countries around the world (including Australia, Belgium, Brazil and Canada) have introduced larger pictorial health warnings on cigarette packs.

You can view the pictorial health warnings from other countries around the world at:
http://www.smoke-free.ca/warnings/default.htm . These warnings provide quite a contrast to those in use in the United States, and may even help increase a smoker’s motivation to quit simply by viewing them online.

Some recent studies indicate that current U.S. warnings are woefully ineffective at getting the attention of smokers, communicating health risks or motivating smokers to quit, whereas the type of pictorial warnings used in Canada are much better. David Hammond and colleagues at University of Waterloo in Canada examined Canadian smokers’ reactions to the pictorial warnings in Canada. Over 90% of smokers had read the new warnings and those who read them, thought about and discussed the new Canadian warnings were more likely to have quit, made a quit attempt, or reduced their smoking three months later. Dr Ellen Peters and colleagues from University of Oregon recently compared US warnings with those in Canada. A majority of both smokers and non-smokers endorsed the use of Canadian-style warnings in the United States.

A bill currently pending in Congress would give the U.S. Food and Drug Administration (FDA) authority to require major changes in U.S. cigarette pack health warnings and require that they cover at least the top 30 percent of the front and back of cigarette packs. The legislation would also allow the FDA to increase the warning size to 50 percent of the front and back panels and adopt graphic or pictorial warnings, as Canada and several other countries have already done. Some countries also include the toll-free number for the national Smokers Quitline next to the warning. Its time to upgrade the health warnings on cigarette packs in the United States to include pictorial warnings and the national quitline number (1-800 QUIT NOW).

Labels: cigarette, pack, warnings

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