Up in Smoke: The American Heart Association on Smokeless Tobacco

 

The American Heart Association published a policy statement in its journal Circulation, titled, “Impact of Smokeless Oral Nicotine Products on Cardiovascular Disease.” (here)  Below, I cite with permission excerpts from a review by Clive Bates, along with my comments.

The smokeless tobacco [ST] policy statement from the American Heart Association is too long to review in depth, but my main take outs are:

1. It’s a modest improvement on what came before and it has factually correct things in it, but it does not work as a basis for policymaking or risk communication.

Clive notes the biggest problem, the conclusion is preordained: “summarize implications of use for [the AHA’s] policy work toward ending tobacco and nicotine addiction in the United States.

So if your goal is a nicotine free society, no level of risk will ever be tolerable, and your search for harms (real, exaggerated or imaginary) will be driven by the need to support this conclusion.  We do not have this “elimination” philosophy with other common recreational drugs - caffeine, alcohol and cannabis, even though these are not risk-free.  We take the approach of managing risks to levels acceptable in society. AHA should also know by now that regulation and risk communication in this field is plagued by unintended consequences - adverse behaviour change (more smoking), illicit trade and risky workarounds - and these consequences can be more severely negative than the intended benefits.

Let me be clear - I am not recommending tobacco or nicotine use to anyone… this is better understood as a phenomenon in society driven primarily by its perceived or real benefits to users - it makes people feel better and feel as though they function better. No space was available in the paper to discuss this important aspect of nicotine use - why people use it. The demand for nicotine is not going to disappear and the availability of nicotine in much safer forms than smoking removes nearly all of the main deterrent for nicotine use - extreme harmfulness over the long term of inhalation of smoke. I suspect there would be a very different attitude to ST if the public had not been confused by years of deceptive risk communications [only 13.4% think ST can be safer than cigarettes - HINTS 2017]. There are no upfront statements that address this risk miscommunication.

2. No clarity on the place of ST on the nicotine risk continuum.

This is the only mention of ST in the AHA statement: “Although there are no safe tobacco products, a continuum of risk across tobacco and oral nicotine products exists, with the greatest risk associated with combustible products such as cigarettes and cigars.” 

Everyone agrees that there is no “safe” tobacco product, and that combustion and smoke produce the greatest risk, but it is unacceptable to ignore decades of evidence proving that ST is only about 2% as risky as smoking.

3. Nothing to correct huge false risk perceptions and more to add to them.

While many studies have found that ST use confers minimal to no increased risk for cardiovascular diseases, the AHA cherry-picked research that portrays ST badly and they ignored, or were ignorant of, those studies’ major flaws.  For example, the AHA cited a seriously defective 2014 Swedish study in Circulation showing increased deaths among snus users with heart attacks (here).  Using that study’s results, my colleague and I found that continuing snus users actually had a lower death rate than those who used neither snus nor cigarettes (here).  Our analysis was so persuasive that the journal published it for the record (here).

Every ST prohibition screed includes a section on oral cancer, and this report, ostensibly about cardiovascular disease, adheres to the formula by quoting an infamous 2016 study by Wyss and colleagues that claimed a positive association of ST use and oral cancer.  Still, in a rare nod to truth and clarity, the AHA authors opine:

“It is noteworthy that many meta-analyses included individuals who reported use of high-nitrosamine ST products from many years in the past. These differences need to be considered carefully when extrapolating to oral cancer effects among individuals reporting use of currently available products with lower nitrosamine levels.”

Kudos, because that is what I have been documenting since 1994.  Wyss revealed that American men had zero excess mouth cancers associated with [low-nitrosamine] dipping or chewing tobacco (Odds Ratio, OR = 0.9), while women, who mainly use[d] [high-nitrosamine] powdered dry snuff, had a 9-fold elevated risk (here).

4. Detailing the mechanisms behind minor risks in a way that conveys greater risk than exists.

Almost every study showing some sort of material risk has been open to confounding or other methodological weaknesses - the high level mortality data show no excess risk for exclusive smokeless use in the US.

The AHA studiously ignores published research that failed to show excess risk from ST use; the FDA took a similar tack in an internal report last year (here). 

5. Not presenting a simplistic approach to nicotine use, and why people use it.

The AHA dwells on nicotine chemistry, toxicity, pharmacology and physiology, but in the end, they focus on the harm of nicotine addiction.  In doing so, they ignore the fact that hundreds of millions of people worldwide consume combustible tobacco and nicotine products, despite the long-term increased risk of dying prematurely from a plethora of diseases that could easily be avoided.

6. Disregards interactions between different forms of tobacco use with radically differing risks.

The AHA repeatedly mentions dual use as a negative side effect of ST, yet the association perpetuates dual use by ignoring or downplaying the well-documented differential risks between smoke and smoke-free tobacco.  This has been going on for decades; in 1991, the CDC reported that at least 23% of ST users also smoked (here).  Imagine how many dual users’ lives would have been extended if health professionals had been honest about the risk differential.    

7. A naive policy platform based on weak evidence of impact and blind to unintended consequences.

This review does have some useful though equivocating text buried within it as the truth is essentially undeniable.

Nicotine is the proximate cause of all tobacco-induced disease because it drives dependence and compulsive use. However, most of the harm from tobacco use results from inhalation of tobacco combustion products, which delivers high levels of oxidizing chemicals, numerous toxic volatile organic compounds, and carbon monoxide. Because oral nicotine products do not expose users to combustion toxins, an important question is the intrinsic toxicity of nicotine.

No, the real question is about the magnitude of risk - how this compares with smoking and how it looks in absolute terms compared to other risks that are routinely tolerated in society. It should also draw attention to the likelihood that ST use is likely safer than vaping, as there is no lung exposure and no thermal processes -just because something contains tobacco doesn’t make it more harmful than something that doesn’t.

Sadly, if predictably, there are no clear statements in this policy statement that aim to reset the public, medical or political misunderstanding of relative risk.  Even on cardiovascular risk there are statements that suggest minimal risk in the American context, but buried deep within

The policy proposals are poorly supported with policy impact evidence and are more like an uncritical shopping list… Given it is a policy paper, it is completely dominated by largely irrelevant biomedical findings, with policy proposals made as if they are somehow obvious, rather than a perturbation of a complex adaptive and interconnected market-based system for nicotine use

The question is what happens to demand for nicotine when you try to adjust behaviour against smokless tobacco use? We have already seen that excessive FDA regulation has caused the vast majority of the vape market to be traded through unauthorised and/or illicit channels. 

If the demand for nicotine is robust, the policy problem is to move to ways of using it that are much less harmful than the dominant method, smoking tobacco. ST, responsibly manufactured and marketed, is one such option.

Amen.

 

 

 

 

 

Breaking News: Snus Benefits Heart Attack Survival

I reported in this blog 10 months ago that data from a Swedish study in Circulation, the journal of the American Heart Association, actually suggested that snus users had a lower death rate after a heart attack than non-users of tobacco (here).  Instead, the journal and the study’s authors promoted their work by claiming that snus poses a grave risk. 

In reviewing the study, Carl Phillips and I found it seriously flawed.  We particularly noted a glaring omission: The authors did not provide death rates among non-users of tobacco as a referent group for tobacco users.  We used information from the study to produce the following estimate for non-users.

Death Rates Among 21,220 Swedes After a Heart Attack, According to Tobacco Use
Tobacco Use	Deaths per 100,000 persons per year
Non-Users*	21.4
Continuing Snus Users	18.7
Snus Users Who Quit	9.7
Continuing Smokers	28.4
Smokers Who Quit	13.5

*Rodu-Phillips estimate; others are from the original study.

In sum, all snus users fare better after a heart attack than people who don’t use tobacco at all.  On June 30, 2014, we wrote the editor of Circulation, asking the study authors to correct errors in their original report, and address our conclusion on snus use. 

Our letter has just been published (reference here), along with the authors’ response.  Although they corrected a significant error that had been overlooked “by all coauthors and 4 reviewers,” they did not respond to our request for confirmation or revision of our estimate.  That effectively confirms our interpretation: Among Swedes who suffer a heart attack, continuing snus users have better survival than non-users.  Snus users who quit after a heart attack have the best survival of all.

Swedish Study: After a Heart Attack, Quitting Tobacco Better Than No Tobacco

A recent study by Gabriel Arefalk and colleagues at the University of Uppsala in Sweden, published in the American Heart Association flagship journal Circulation (abstract here), was purported by the authors, the AHA (here) and the media (here) to show that continuing snus use or smoking after a heart attack (myocardial infarction, MI) is twice as harmful as quitting.   

These conclusions are questionable.  Using the Arefalk numbers, Carl Phillips and I found that snus users, and perhaps even some smokers, are better off than non-users. 

We have submitted a letter to the editor of Circulation, and Carl has the full text of our letter in his CASAA blog post (here).    

The bottom line is that the authors tried to spin the results as suggesting that continuing snus use is dangerous after an MI.  In fact, continuing snus users actually had a lower death rate than people who used neither snus nor cigarettes. 

Whatever is happening in this population, it clearly does not support the simplistic “snus is bad” mantra.  There is a glaringly obvious explanation for why people who quit snus (or smoking) after an MI fare better than those who do not:  Those who are healthy (except for the recent MI, of course) and hope to recover are more likely to take steps to minimize their risks.  After being advised to give up snus, many also get physical therapy, exercise and maintain a healthier diet.  Meanwhile, those who are less healthy may not make changes in an attempt to regain long-term health.  The Arefalk analysis may not have adequately controlled for these confounding factors.

Of course, this would only partially explain the better outcomes of quitters compared to continuing users; it does nothing to explain why all of them (except those who continued to smoke) apparently fared better than non-users.  There are possible explanations for this in the form of statistical artifacts or real effects.  The key observation is that these unreported results do not support the authors’ main interpretation that snus use is dangerous after an MI.

With the publication of this article, peer review appears to have been woefully inadequate.   The prime statistical error we discovered is the key number reported in the first paragraph of the article’s results section.  Reviewers of this study failed to detect the glaring error.

Even without correcting that error or calculating the mortality rate for non-users, the (incorrect) number for the population as a whole the authors reported can still be compared to rates for people who used snus or cigarettes at the time of their MI.  This is enough to raise red flags about the analysis and conclusions, since it is still higher than the rate for those who kept using snus, and far higher than the rates for those who stopped using either product. 

In 2011 Arefalk was lead author on a study making dubious claims about snus use and heart failure.  I described that effort as “neither legitimate nor persuasive until the authors resolve the fundamental questions about the analysis.” (here).

The current article in Circulation is a classic example of anti-tobacco propaganda.  Credible epidemiologic studies do not report risks in exposed groups without reporting the comparable baseline risk among the unexposed.  The authors, and the journal editors and reviewers who enabled them, omitted this critical information.  Our letter to the editor gives them a chance to correct these deficiencies.