Thursday, April 30, 2015

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 UseDeaths per 100,000 persons per year
Continuing Snus Users18.7
Snus Users Who Quit9.7
Continuing Smokers28.4
Smokers Who Quit13.5

*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.

Wednesday, April 22, 2015

The Scientific Case for Regulating Menthol: Next to Nothing

Ever since the FDA started regulating tobacco in 2009, a principal objective of tobacco opponents has been a menthol cigarette ban.  Congress could have banned menthol in its authorizing legislation, but Matthew Myers, president of Tobacco-Free Kids and principal architect of the legislation, knew that menthol was a congressional poison pill.  Instead, Congress directed the FDA to conduct a special investigation that prohibitionists hoped would lead to a ban.

The FDA is obligated to act in an unbiased fashion and base its actions on credible scientific evidence.  When, in 2011, the FDA Tobacco Products Scientific Advisory Committee found, on weak evidence, that menthol had a negative impact on public health, a federal judge barred the agency from acting because the committee was tainted by conflicts of interest.

In 2013, the FDA tackled menthol again, issuing a “Preliminary Scientific Evaluation of the Possible Public Health Effects of Menthol Versus Nonmenthol Cigarettes.”  As I pointed out, the agency’s case against menthol was entirely unconvincing. A subsequent filing by Lorillard underscored that fact.    

Late last year, investigators from Reynolds American and Environ International published a series of articles on the impact of menthol cigarettes on current smoking patterns, smoking initiation, measures of dependence and smoking cessation.  While previous reports from anti-tobacco activists used cherry-picked data from various sources, the Reynolds-Environ studies utilized well-documented methods to analyze data from four major surveys: the National Health Interview Survey (NHIS), the National Survey on Drug Use and Health (NSDUH), the National Health and Nutrition Examination Survey (NHANES) and the Tobacco Use Supplement to the Current Population Survey (TUS-CPS).  Following are topline results from the Reynolds-Environ studies, published in Regulatory Toxicology and Pharmacology.

Current Smoking Patterns

“In summary, the current analyses examine menthol cigarette use, overall and within demographic strata, among four nationally representative samples of U.S. adults, and in some instances among youth. Findings from these analyses confirm that adult female smokers are more likely to use menthol cigarettes compared to male smokers, and that a majority of adult non-Hispanic Black smokers use menthol cigarettes; these patterns persist regardless of smoking frequency. Smokers in other race/ethnicity groups may be more likely to use menthol cigarettes compared to non-Hispanic White smokers, but are not more likely to use menthol cigarettes compared to smokers overall. Finally, higher proportions of younger adult smokers (aged 18–25 years) report using menthol cigarettes compared to older adult smokers (aged 26–29 years and 30+ years), but statistically significant differences are inconsistent and numerical differences are small in magnitude; the limited data for youth smokers do not provide consistent patterns of menthol cigarette use.”

Smoking Initiation

“Results from the analyses provided herein indicate that menthol cigarette use is not associated with an earlier age of initiating smoking or a greater likelihood of being a daily versus non-daily smoker; and, that menthol cigarette preference is not greater among new, less-experienced compared to more-established youth smokers.”

Measures of Dependence

“In summary, findings from the current analyses that examine number of cigarettes smoked per day, time to first cigarette after waking and HSI [the Heaviness of Smoking Index], coupled with evidence from previous studies based on nationally representative populations do not support an evidence-based conclusion that menthol in cigarettes increases dependence among U.S. smokers. Results from the current analyses indicate that menthol smokers do not report smoking a greater number of cigarettes per day compared to non-menthol smokers; that the distribution of menthol compared to non-menthol smokers into categories of time to first cigarette after waking is nearly identical; and, that menthol smokers are generally more likely to be in a lower versus higher HSI (i.e., dependence) category.”

Smoking Cessation

“Data from the NHIS (2005 and 2010) generally suggest no statistically significant association between menthol cigarette use and being a former versus current smoker for any of the three race/ethnic groups, while data from TUS-CPS (2010/11) generally suggest a statistically significant inverse association between menthol cigarette use and having quit smoking, particularly among non-Hispanic Blacks…[The analyses] provided inconsistent results with regard to menthol cigarette use and quitting, both within surveys (i.e., comparing race/ethnicity groups) and between surveys (i.e., same race/ethnicity group across surveys).”

In summary, these comprehensive analyses document that menthol cigarettes are more popular among women, blacks and younger smokers.  The surveys show that menthol plays virtually no role in smoking initiation and dependence.  With respect to whether menthol affects cessation, the NHIS and the TUS-CPS reveal inconsistent results.

Earlier studies of menthol cigarettes showed that they may be associated with lower risk for lung cancer (here) and stroke (here), although this does not mean that they are safer than nonmenthol cigarettes.  The Reynolds-Environ studies provide evidence that there are no significant differences between menthol and regular cigarettes with respect to smoking initiation, addiction to nicotine, or cessation. 
This set of publications use publicly available data; the methods are completely transparent and comprehensive; the findings are broad and highly credible.   

There is no justification for FDA action to ban or otherwise restrict menthol in cigarettes.

Thursday, April 16, 2015

Reality Bites the Dust in New Smokeless Tobacco Study

It’s surprising what passes for “science” in some journals today.  Chemical Research in Toxicology has published a study from the University of California’s Berkeley and San Francisco campuses making this extraordinary claim: “Children living with smokeless tobacco [ST] users may be exposed to carcinogenic tobacco-specific nitrosamines [TSNAs] via contact with contaminated dust and household surfaces.”

The research was an offshoot from a larger effort looking for an environmental cause of childhood leukemia.  Families who participated in the study were divided into three groups: non-users of tobacco, smokers and ST users.  The contents of dust bags from their household vacuum cleaners were analyzed for NNN and NNK, two TSNAs that are considered to be causes of cancer.

Almost every household – even those with no tobacco users – had NNN and NNK in their dust, but researchers found “higher” levels of these agents in every gram of dust from an ST home – about 5 to 10 nanograms.  Keep in mind that a nanogram is one billionth of a gram, and a gram is less than four one-hundredths of an ounce. 

Each gram of moist snuff contains about 5-10 micrograms of NNN/NNK, about 1,000 times higher than the dust in this study (see my previous blog entry).  At one can a day (32 grams), the typical ST user is exposed to 32,000 times more NNN and NNK than the hypothetical child who eats a gram of dust every day.  It is well established that long-term use of ST even at that level is not associated with a significant increase in risk for ANY cancer.      

The California exposure data may be accurate, but the findings are of no practical consequence, other than to serve as fodder for hyperbolic anti-tobacco claims.

Tuesday, April 7, 2015

FDA Must Correct Snus Warnings

An FDA advisory committee is meeting this week to discuss a landmark proposal to correct federal health warnings that have been misleading the public for almost 30 years.
Swedish Match, a manufacturer of the Scandinavian smokeless product called snus, petitioned the FDA to eliminate two package warning labels concerning mouth cancer, gum disease and tooth loss.  The company submitted numerous scientific studies documenting that these warnings, mandated in 1986, misrepresent the facts.
The mouth cancer warning was based on a flawed 1981 study of powdered dry snuff, an obscure product.  The reported cancer risk was far lower than from smoking, but it was incorrectly represented as high, and applicable to all American smokeless products (here and here).  In fact, numerous epidemiologic studies document that users of American moist snuff and chewing tobacco, and Swedish snus, do not have significantly elevated mouth cancer risk.

The gum disease/tooth loss warning is also unfounded.  There is no credible scientific evidence that smokeless tobacco is an independent risk factor for any dental problem.

Swedish Match has also urged the FDA to replace another 30-year old deceptive warning, “This product is not a safe alternative to cigarettes,” with this: “No tobacco product is safe, but this product presents substantially lower risks to health than cigarettes.”  The replacement warning is identical to a change requested by RJ Reynolds four years ago in a citizen petition filed with the FDA.  The agency ignored that petition.
The not-a-safe-alternative warning is particularly egregious, as I note in my book, “For Smokers Only” (here).  Accompanied by an incessant campaign for tobacco prohibition by government agencies and anti-tobacco extremists, the warning, appearing on packages and in advertising, has deceived millions of smokers.
The current warnings have been shown to discourage smokers from switching (here).  The proposed label would set the facts straight.  Numerous studies (reviewed here) document that the health risks of smokeless tobacco use are so low as to be barely measurable, even for mouth cancer.  (The European Union removed warning labels for that disease from Swedish snus packages in 2001.)  Statistically, smokeless users have about the same risk of dying from their habit as automobile users have of dying in a car accident.
Swedes have a history of embracing harm reduction. They invented the modern seat belt, and they’ve eagerly substituted relatively safe snus for cigarettes.  Snus use is directly associated with low smoking rates in Sweden, where men have smoked less and used more smokeless tobacco than in any other developed country.  The result: Swedish men have the lowest rates of lung cancer -- indeed, of all smoking-related deaths -- in the developed world.  If men in the rest of the EU smoked at the rate of Swedish men, there would be over one-quarter-million fewer dead smokers in the EU each year. (here).  Inexplicably, the EU has banned snus in every country except Sweden, denying smokers this life-saving option.

The good news is that snus is now widely available in the U.S. (as are e-cigarettes, another safer-than-cigarettes option).  A 2006 study funded by the National Cancer Institute (here) estimated that four million American smokers would switch to snus if they were informed about the vastly lower health risks of that product.  Research shows that smokeless tobacco (here) has already helped many smokers quit deadly cigarettes.

With no good science behind them, anti-tobacco extremists have resorted to scaremongering.  Dr. Michael Steinberg, director of the Tobacco Dependence Program at Rutgers, recently told NPR this convoluted story:

“If you imagine a young person who sees on a label that this is a less harmful tobacco product, they may interpret that as, ‘Oh, this is not harmful at all. I might as well try it and see what it's all about.’  And that person can still become addicted to the nicotine effects, which could either lead to them becoming a long-term smokeless tobacco user, or could escalate to them starting to smoke cigarettes.”

The FDA cannot take action based on fantasy scenarios.  Swedish Match’s request is scientifically sound.  Revised labels will tell the truth about snus, giving U.S. smokers life-saving information.