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Evidence, not authority, is what should determine policy

My Times column on statins, snus and vaping:

One of the most salutary examples of people in authority getting risks wrong is a paper written in 1955 by the first head of the environmental cancer section of the US National Cancer Institute, Wilhelm Hueper. The title was “lung cancers and their causes” and he was absolutely convinced that “cigarette smoking is not a major factor in the causation of lung cancer”, because he thought this was a cheap shot by the chemical industry to divert attention away from pesticides.

We now know that smoking is a major cause of lung cancer, whereas pesticides are not. History is littered with example of experts being too reassuring about some risks, too alarmed about others. Washing hands between dissecting women who died in child birth and delivering babies? No risk, said the nineteenth century medical establishment, ostracizing Ignaz Semelweiss who had had the temerity to suggest otherwise. Dietary fats cause heart attacks, insisted the medical establishment for the best part of five decades till very recently. It was once the consensus that tonsils should be removed; no longer.

So I am no fan of arguing from authority on matters of risk. It’s evidence that counts, especially randomized controlled trials, the gold standard of science. The study published last week finding that statins are relatively safe, and that prescribing them to healthy people at even low risk of heart attacks should save many lives, made this point. The authors argued that the pro-statin evidence comes from randomized controlled trials, while the anti-statin arguments “reflect a failure to recognise the limitations of other sources of evidence”, a polite way of saying they are health-fad claptrap.

The argument is not that statins are risk-free, but that the benefits outweigh the risks: it’s the relative risk that counts. Large, randomised trials find that statins greatly reduce the risk of heart attacks and strokes during each year that they continue to be taken. That benefit far outweighs the relatively modest risks from side-effects. Notice that it’s the evidence that is convincing, not the authority of those presenting it. I could not care less that there is a medical consensus that statins are safe unless that consensus is based on good evidence.

The opposition to vaping provides a contrasting example where prejudice against tobacco products seems to have closed the minds of the medical establishment. Until recently most public health experts made precisely the same mistake with electronic cigarettes that the opponents of statins make – thinking only of the risk of vaping, not the benefit. Recent headlines claiming that “Vaping as bad as fags” (the Sun) or “Vaping as bad for your heart as smoking cigarettes, study finds” (Telegraph) were based not on a randomized controlled trial measuring the risks and benefits of both, but on one very limited small study of one largely irrelevant effect reported at a conference.

Worse, that study compared 30 minutes of vaping with five minutes of smoking and concluded that both can induce temporary arterial stiffening – a well-known effect of nicotine that has not been linked to disease, and that is also produced by caffeine. The damaging effect of smoking, both to the heart and in terms of cancer risk, comes not from nicotine at all but from combustion products. So the headlines were based on junk science. They could have read: “Vaping no worse for you than coffee, study finds”.

Tobacco-control advocates say that the “end-game” for smoking will have been reached in a country when its smoking rate falls below 5%. This is a very long way off as global smoking rates continue to rise and smoking remains common even in countries with strong tobacco-control policies such as Britain. Here 26% of young men still regularly smoke. 

However, one country is fast heading towards achieving the end-game result. According to Swedish government figures, only 6% of Sweden’s young men regularly smoked in 2015. The only plausible explanation for this extreme outlier is that 25% of Swedish men use “snus”, a sort of tobacco tea-bag pressed against the gums – and do so instead of smoking.

As a result, not only is Sweden on the way to becoming the first country to get below 5% of men smoking, but it is the country with the lowest rate of lung cancer among men in Europe (it’s higher among Swedish women, who don’t use snus much), as well as low rates of other smoking-related illnesses such as heart disease. A spectacular case of harm reduction that puts even statins in the shade.

Acknowledging this data, America’s Food and Drug Administration last year authorized snus to help protect public health. The European Union has not followed suit. This health-giving product is not just discouraged, it is still wholly illegal through the EU – except in Sweden. Herein lies an interesting tale. When Sweden joined the EU in 1995, its peoples’ snus habit became an issue in the negotiation. The country was reluctant to accept a ban on such a popular product, which, even then, was obviously proving a safer and cleaner alternative to smoking.

So the EU was forced to make an exemption for Sweden. To this day, 21 years later, you can legally buy and sell snus in the European Union only in Sweden. Britain, incidentally, led the charge to ban snus within the EU, one Edwina Currie being the minister at the time, and our government remains impervious to the evidence cited above. Many millions of lives could have been saved without that prohibition.

In preparation for a big conference on the subject, the World Health Organisation last week set out a list of things it wants countries to do to hamper the growth of vaping, such as a ban on the advertising. It says not a word about trying to overturn the total bans on vaping in many countries, even though it is now very clear that vaping is mainly done by smokers and that it reduces the risks of smoking-related illnesses drastically – by 95% according to Public Health England. 

There is no fundamental difference between vaping (or snus) and statins? All treat conditions that carry high future risks – smoking addiction and high cholesterol. All carry risks themselves but much smaller ones than their benefits. Just as taking statins is better for you than not taking statins if you are at risk of heart disease, so switching to vaping or snus is far better for you than continuing to smoke.

By Matt Ridley | Tagged:  rational-optimist  the-times