Archive for the ‘dodgy studies’ Category

Is actively giving smokers a known carcinogen ethical?


Let’s get this out of the way straight away: I’m not a smoker. With that in mind, you might think that I would welcome the headline article that I spotted on the BBC News website today, “Smoking ’causes damage in minutes’, US experts claim“:

Smoking damages the body in minutes rather than years, according to research in the US.

The report, published in Chemical Research in Toxicology, shows that chemicals which cause cancer form rapidly after smoking.

Scientists involved in the small-scale study described the results as a stark warning to people considering smoking.

Anti-smoking charity Ash described the research as “chilling” and as a warning that it is never too early to quit.

The long term impact of smoking, from heart disease to a range of cancers, is well known. This study suggests the damage begins just moments after the first cigarette is smoked.

My first reaction was a rather prolonged Gallic shrug. This is news?! Quite frankly, the concept that inhaling a large amount of tar, nicotine and thousands of other exotic compounds might start doing your body no good straight away is not an unexpected finding.

Secondly, people who smoke these days are pretty much aware of the potential damage that they might be doing to themselves. I doubt that this study will change anyone’s views on this either way and, as a libertarian, I believe that what people do with their own bodies is no-one’s business except their own.

However, the major problem that I have with this story relates to the following section from the study abstract:

Polycyclic aromatic hydrocarbons (PAH) are among the likely major causative agents for lung cancer in smokers. PAH require metabolic activation to exert their carcinogenic effects, and one important pathway proceeds through a three-step sequence resulting in the formation of diol epoxides, which react with DNA to produce adducts that can cause mutations and initiate the carcinogenic process. However, no previous published studies have examined this critical pathway in humans specifically exposed to PAH by inhalation of cigarette smoke … Twelve subjects each smoked a cigarette to which [D10]phenanthrene had been added.

This aspect of the study has already been addressed by Leg-Iron over at his blog; however, it is worth repeating: we have a clinical study, funded by the US National Cancer Institute, where a known carcinogen was actively administered to human study participants.

The full study manuscript is not freely available, so it is not possible to check the methods section for details of how this design got ethical approval. Would be good to know more, since without further explanation I think that this sets a dangerous precedent…