Wednesday, 18 April 2012

Snus: they knew all along (part 2)

While doing some research recently, I came across a letter in a library archive written by Dr Richard Peto to Dr. B. MacGibbon. Peto was, and is, a highly respected epidemiologist who worked closely with Richard Doll on smoking and health.

The letter is dated 28th June 1984. Two months earlier, the Daily Mail had run a story about Skoal Bandits, an American form of snus made by US Tobacco Inc. who were due to build a factory in Scotland. Shortly thereafter, ASH's director David Simpson started a moral panic about this smokeless tobacco product which ultimately resulted in the EU ban on oral tobacco (1992). See Chapter 4 of The Art of Suppression for the full story.

I do not know who Dr. B. MacGibbon was or why Peto was writing to him, but Peto begins by recommending that some research into the saliva concentrations of snus users be conducted "fairly urgently". He continues...

I have given some further thought to the question of how many cancer deaths would be likely to be caused each year if one-third of the British population were to become habitual tobacco suckers.

Then, basing his figures on data from the US and UK...

This suggests that if about a quarter of the British population took to dipping 100 gms of tobacco a week, then in the long run “only” some 500-1000 excess deaths/year would result (see Appendix [which is a couple of studies, including the influential study by Deborah Winn looking at women in North Carolina - CJS]).

Maybe Skoal Bandits would be worse than SE US snuff, or maybe (especially if you take the advice in the first part of this letter! [ie. to carry out research "fairly urgently" - CJS]) they would be less hazardous. In any case, no matter what epidemiological studies you mount, you probably won’t get even a preliminary answer this century, so as a practical basis for action I suggest you assume that the adoption of Skoal Bandit-like products by a quarter or a half of the British population will cause about 1000 cancer deaths a year. In contrast, tobacco smoking currently causes about 100,000 British deaths a year!

This may be wrong – they could be carcinogenic, and the Asian experience with oral cancer suggests that they could be a lot more carcinogenic than I’ve estimated, but in any case you have most of what you need for political action, viz:

  • The risks are not zero
  • The risks can probably be reduced by immediately commissionable laboratory research;
  • The risks are much, much less than those of cigarette use.

The final thing you need is to know whether they will help avoid tobacco. No proof is possible, but it is noteworthy that among women in North Carolina, where both products have been widely available for decades,

  • The proportion of smokers among snuff-dippers is only one-third as great as that among non-dippers, and
  • Even among those dippers who smoke, mean cigarette consumption Is significantly lower than among non-dippers who smoke.

I suspect that, no matter what the risks might be, Skoal Bandits and allied products would be allowed to be sold [alas, this prediction was wrong - CJS]. Fortunately, however, the above arithmetic suggests that this may well do more good than harm. In any case, one should try to avoid producing a situation where the warnings or statements about Skoal Bandits etc. are so strong as to divert attention from the much more serious hazards of tobacco smoking.

He concludes by saying:
"The real message is that there is a hazard, but that it’s much less than that of smoking, and that a widespread shift to such products could probably save a lot of lives."

As I mentioned recently, Peto was not alone in seeing the harm reduction potential of snus. In 1985, the addiction expert M.A.H. Russell published a letter in the Lancet, estimating that 49,000 premature deaths would be prevented by a switch from cigarettes to Skoal Bandits. Unfortunately, and not for the last time, the voices of scientists were drowned out by those of activists who were itching for prohibition.