Thursday, October 29, 2009

New Study Finds Nicotine Gum May Pose Carcinogen Hazard to NRT Users; Will Anti-Smoking Groups Call for Removal of Oral NRT Products from Market?

A new study published online ahead of print in the journal Cancer Research reports that the use of nicotine gum is associated with significant exposure to a potent carcinogen and concludes that oral nicotine replacement therapy (NRT) use therefore poses a potential carcinogenic hazard to some users. The same problem was not detected with the nicotine patch. Since the study concludes that the carcinogens were likely formed in the stomach, the problem would also not be expected to occur with the use of nicotine inhalers or electronic cigarettes.

In the study, urine levels of NNN - a potent carcinogen - were measured at baseline in smokers. Then, the smokers quit smoking by using either nicotine patches, nicotine gum, or nicotine lozenges. The group was followed for a period of two months after quitting smoking, with periodic follow-up measurements of NNN in their urine.

The major results and conclusion of the study was as follows:

"In 13 of 34 nicotine gum or lozenge users from both studies, total NNN at one or more time points after biochemically confirmed smoking cessation was comparable to, or considerably higher than, the baseline levels. For most of the subjects who used the nicotine patch as a smoking cessation aid, urinary total NNN at all post–quit time points was <37% of their mean baseline levels."

Of note, experts estimate that 36.6% of nicotine gum users are long-term users. Thus, these concerns are not just hypothetical ones.

Because the authors suggest that the NNN is being formed endogenously in the stomach in association with oral NRT use (this would explain the absence of this NNN problem in nicotine patch users), one would surmise that nicotine inhalers and electronic cigarettes do not pose similar problems of significant carcinogenic exposure to users due to the endogenous formation of NNN.

The Rest of the Story

Given this finding that oral NRT users may experience significant carcinogenic exposure and that this exposure could persist over long periods of time due to the way these products are commonly used, the question is: Why aren't the same anti-smoking groups which are calling for the removal of e-cigarettes from the market also calling for the removal of oral NRT products?

How can the Campaign for Tobacco-Free Kids, the American Heart Association, the American Lung Association, Action on Smoking and Health, and the American Legacy Foundation justify their calls for a ban on electronic cigarettes - which have not been shown to pose any carcinogenic hazard - while they remain silent about the risks of oral NRT use - which has now been shown to pose a significant carcinogenic hazard in a substantial proportion of users?

Clearly, there is a need for more research on these products, as suggested by the study authors. But why allow the product to remain on the market while these studies are conducted? If your attitude is that e-cigarettes must be taken off the market until further studies are conducted, then why should oral NRT products remain on the market during those same studies?

Let me make a clear distinction, however, between oral NRT products and electronic cigarettes. In the first case, there is clear evidence of a significant carcinogenic exposure that could potentially put users at risk, especially the 36.6% who use the product long-term. In the second case, there is not any evidence of a carcinogenic hazard, or any other hazard for that matter (other than the effects of nicotine itself, which is the same in all of these products).

For the anti-smoking groups that are calling for a ban on electronic cigarettes, I pose the following challenge: please identify one specific chemical exposure which is likely causing significant harmful effects in vapers.

For the anti-smoking groups that are calling for a ban on electronic cigarettes in public places, I pose a similar challenge: please identify one specific chemical exposure which is likely causing significant harmful effects in non-vapers.

It is all well and good to say: "We don't know if these products are safe. We should ban them until we know they are safe." But that's an uninformed opinion. There is plenty of scientific evidence out there already about the safety of the product. It has been studied extensively in the laboratory and its chemical components have been characterized. In fact, we know far more about the chemical components of electronic cigarettes than we do about the components of Marlboros.

Policy needs to be based on science, not pure conjecture. Let's look at the science. Based on the studies that have been done and the information about adverse effects of the product during its 3 years of use in the United States, as well as the characterization of the components in the product, what are the specific chemical exposures occurring among vapers and non-vapers that these anti-smoking groups posit may pose a significant health hazard?

If these groups cannot name a potential specific hazard, then it seems imprudent to ban the product, take it off the market, or even to ban its use in public, as this is going to result in forcing large numbers of vapers to go back to cigarette smoking.

You see, the anti-smoking groups have it all wrong. They are arguing that we need to ban the product because it is possible that it could be having an adverse effect on users (or non-users) and so to be safe and make sure that we are not causing harm, we need to carry out more studies (of course, they have not specified what studies are needed, since we already have 3 years of use of the product with no reported adverse effects).

Instead, I argue that to remove the product from the market, or even to ban its use in public, would result in a known and definite public health hazard: thousands of vapers returning to cigarette smoking, which is without doubt going to cause disease and death.

Public health is about reducing disease and death, not increasing it because of scientific uncertainty. Scientific uncertaintly is always going to be present to some degree. We cannot let that uncertainty get in the way of making rational decisions and we certainly cannot allow it to make us forget the information that we do have. And the information that we do have clearly suggests that pulling e-cigarettes off the market would do a lot more harm than good.

My analysis, of course, is subject to reconsideration. If any of the anti-smoking groups can present a specific chemical exposure that could likely be causing significant harm in vapers or non-vapers (other than the nicotine, which is of course present in all NRT products), then I will reconsider my position.

But based on the current evidence available, it is very clear to me that allowing ex-smokers to continue using electronic cigarettes, even in public places, is in the best interests of the public's health. Forcing them to return to cigarette smoking is the last thing in the world that public health groups should be doing.

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