Friday, 20 October 2017

Alcohol and cancer – again!

Barely a day goes by without some new “threat” to our health being announced by epidemiologists or other health campaigners. For these people, the meaning of life appears to be the elimination of anything enjoyable in order to achieve maximum longevity. Key to this is the elimination of “risk factors” from our diet and lifestyles. The key technique used to frighten us all into abstinence is to concentrate on cancer risks. Here an old trick is used – take a very small baseline risk and measure the increase to that risk that arises if you engage in “heavy” drinking. The effect of this is to give prominence and publicity to very large percentage increases in very small baseline risks.

The Alcohol Health Alliance (AHA) has taken to Twitter to publicise its message that alcohol = cancer = death. The Twitter headline reads: “Alcohol is linked with at least seven types of cancer” and then lists them on a handy infographic of the body as mouth and upper throat; larynx; oesophagus; breast; liver; and bowel cancers.

Of course, a “link” is not the same thing as a “cause” but they would like you to think it is. This scare-mongering is entirely consistent with a revision of the low-risk drinking guidelines on the basis there is “no safe level of consumption in respect of the epidemiological risk of developing cancers”, and “the cancer risks of drinking is a game-changer”. It is, of course, accepted that excessive consumption of alcohol is causally related to a small number of cancers – but the risk is dose-related.

Taking oral cancers as an example, what is the overall risk caused by drinking alcohol? According to Cancer Research UK, about 7,300 oral cancers are diagnosed in the UK a year. Of those, tobacco smoking was identified as the cause in 65% of cases. Alcohol consumption accounted for 30% of these –2,190 cases. In total, 30 million adults in the UK drink at least once a week. Of those, 2,190 of them develop an alcohol-related oral cancer – that is 0.007% of regular drinkers. And remember, these figures include very heavy drinkers as well as moderate and light drinkers – so don’t be panicked into abstention just yet.

Every such death is a tragedy but the actuarial risk is tiny. The proposition anything that raises the epidemiological risk of a cancer “isn’t safe” is therefore problematic. In everyday life people make trade-offs. They don’t ask “is this product or behaviour safe?” they ask “is it safe enough?” We do this all the time and not just in relation to food and drink. We don’t ask whether driving a motor vehicle is safe, we ask is it safe enough? In other words, do the benefits of driving justify me in taking the risks? When we are told tobacco-smoking results in the premature death of half of all smokers, that may deter people from starting or persuade existing smokers to quit. However, if you were told 0.021% of regular drinkers die from an oral cancer, would that put you off? It is this kind of epidemiological paranoia that leads health cranks to call for abstinence, and lowering of the lower-risk drinking guidelines is but a staging post on that journey.

However, what is missing from the AHA’s misleading messaging is any reference to the beneficial effects of moderate alcohol consumption. The life-prolonging effects of moderate alcohol consumption are on a firm scientific footing. Despite the AHA and its cronies’ science denial, Sir Richard Doll (the epidemiologist who discovered the link between tobacco smoking and cancer) has revealed there have been dozens of studies in the past 30 years that have vindicated the J-curve that illustrates the benefits of moderate drinking in terms of greater longevity for moderate drinkers compared with “never-drinkers”. If science indicates that alcohol conveys significant life advantages, why does the AHA act as though alcohol is evil?