Tuesday, February 13, 2007

New Study Casts Doubt on Significance of Harvard Nicotine Yield Report and Wisdom of FDA Tobacco Legislation

A new study published in the current issue of Tobacco Control concludes that machine-measured yields of nicotine and toxins in cigarettes are virtually meaningless, having no association with actual human exposure on either an individual or a population basis.

In the study, researchers reviewed a number of technologies used to measure nicotine and toxin emissions from cigarettes. The purpose was to assess how well these machine smoking regimes: "1) Represent human smoking behaviour, 2) Reduce the potential for industry exploitation, particularly in the area of risk communication, and 3) Serve as suitable measures for product regulation."

In terms of the first goal, the researchers concluded that none of the machine measurement methods had any meaningful association with actual human exposure or risk of disease, either on an individual or a population level:

"Although each of the testing regimes will help to "characterise" how a product performs under a given set of smoking conditions, none of the smoking regimes "represent" human behaviour in terms of compensatory smoking and none is likely to produce emissions that will be markedly associated with human exposure or risk, either for individual smokers or for population-level differences between brands."

In terms of the second goal, the researchers concluded that the use of machine-measured nicotine or toxin yields leaves open the door to serious distortion of smoking risks in communications to the public:

"After nearly 40 years—and after great cost to public health—the public health community is now coming around to the realisation that lower ISO emission cigarettes are not lower-risk products. Unfortunately, many regulators fail to understand the distinction between "product characterisation" and predicting human exposure. At the same time as they insist that cigarette emissions are not measures of risk, various regulators continue to use cigarette emissions in ways that assume a link between the machine emissions and human exposure. Many jurisdictions continue to require that quantitative levels of tar, nicotine and carbon monoxide appear on packages. These numbers continue to be misunderstood and misused by smokers, including smokers in the most affluent and highly educated countries in the world. To date, there is no evidence that quantitative emissions constitute effective consumer information, and several scientific bodies have rightly called for the removal of these emissions from packages. ... the tobacco industry should be prohibited from using machine emissions in any of its labelling, advertising or marketing directed at consumers, even if accompanied by "warnings" or disclaimers, such as those that currently appear in the US and Europe."

In terms of the third goal, the researchers concluded that because of the general lack of a relationship between machine-measured emissions and actual exposure, and because of the fact that smokers will change their behavior in response to varying constituent yields, these emission measurements are not currently suitable as measures for product regulation:

"patterns of use must be examined to understand the interaction between product design and smoking behaviour in humans, and to identify systematic differences across products. Products that deliver fewer toxins for a fixed volume of smoke and also promote greater smoke intake when used by consumers are not lower-risk products. Likewise, products that deliver higher amounts of toxins, but discourage repeated use might potentially be seen as harm reducing compared with conventional cigarettes. Measures of realistic puffing behaviour and inhalation patterns are, therefore, important for understanding different chemical and biological profiles associated with products."

The researchers go so far as to conclude that because these machine-measured nicotine and toxin yields are so meaningless, they should be removed from all cigarette labeling and that communicating this information to the public is inherently misleading, deceptive, and likely to create an erroneous impression of the actual health risks of tobacco products, even if the statements are accompanied by disclaimers.

The Rest of the Story

If you're paying attention, and you think about it for a minute, you will realize that what this means (if the researchers' conclusions are valid), is that the Harvard nicotine yield report was essentially meaningless and that despite the report's disclaimer at the end, it was inherently misleading to the public about the public health risks associated with lower or higher nicotine products.

This new review article concludes that machine measured yields - including nicotine yields - have no meaningful association with actual human exposure, either in individuals or on a population level. It concludes that nicotine yield differences between brands are also meaningless in terms of actual exposure.

Well if that's true, then there is no significance to a report which concludes that machine-measured nicotine yields have increased slightly. It simply has no implications for drawing conclusions about either individual or population-based exposure in actuality.

The Harvard report did acknowledge this point, noting that "The increase in smoke nicotine yield does not necessarily signify any change in exposure within the population of smokers, particularly as human smoking behavior is compensatory and will adjust for differences in smoke yield."

However, as the Tobacco Control article points out, this disclaimer alone is not enough to prevent the public from being widely misled - as has happened.

This article also makes it clear that the FDA tobacco legislation, as currently proposed, will not only fail to protect the public's health, but will likely lead to government deception of the American consumer. The government, instead of tobacco companies, would (under the proposed legislation) control the machine-measured yields of various constituents, giving consumers the false impression that this regulation of machine-measured yields has any relationship whatsoever to human health.

In other words, what we as tobacco control practitioners have taken the tobacco companies to court over would now be something practiced by the U.S. government.

There are 2 very strange aspects to this story, which, for the life of me, I cannot figure out.

1. First, after concluding that machine-measured nicotine and toxin yields are essentially meaningless and have no relationship to actual exposure or actual health risk on an individual or population level, and after concluding that this information has no consumer value and should be taken off cigarette labeling, the authors of this paper conclude: "We strongly endorse the need to make information on cigarette emissions public to advance the evidence base for effective product regulation."

That makes no sense whatsoever. They just got through describing in detail why this information is meaningless, and they went so far as saying that the information must be taken off labeling so as not to mislead anyone. They also just got through saying that merely by providing this information, the tobacco companies are committing fraud and deceiving consumers about the true risks of their products. So how do you get from there to a conclusion that there is a "need" to make this information available to the public?

2. Second, in the Harvard nicotine yield report itself, after noting that "the increase in smoke nicotine yield does not necessarily signify any change in exposure within the population of smokers, particularly as human smoking behavior is compensatory and will adjust for differences in smoke yield," why do the authors nevertheless go ahead and draw their conclusions as if the increase in nicotine yields does necessarily signify a change in exposure within the population of smokers?

I seem to really be missing something here. Maybe it's just advancing age, but the logic of the policy analysis that is going on in tobacco control right now is evading me completely.

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