Some time ago there was an entry in Punch, the UK satirical magazine, where it was said that “everything that gives me pleasure has been shown to cause cancer in mice”.
It has now become clear that alcohol has joined the list of agents which can cause cancer well beyond what was previously known to be the case.
We all knew, of course, that excessive drinking is associated with a whole list of problems, including liver disease in particular, as well as throat cancer. Moreover, we are also well aware of the disastrous effects of alcohol as a cause of road carnage and other accidents, as manifested by the excessive numbers of those seeking treatment at hospital emergency departments following weekend binge drinking.
But for those who have always thought of themselves as moderate drinkers, the news is also not so good.
A recent study carried out by Madlen Schütze and her colleagues at the German Institute of Human Nutrition in Germany and published in the British Medical Journal (April 8) compared rates of cancer in over 500,000 drinkers from 10 European countries over the period 1992-2000.
The results are quite disturbing. These authors found that up to 10 per cent of cancer in men and three per cent in women were attributable to alcohol consumption.
Risk was particularly high, as expected, for throat cancer: 44 per cent of cancers of the throat and pharynx in men were due to alcohol (25 per cent in women). Alcohol accounted for 33 per cent of cancers of the liver in men (18 per cent in women).
For colorectal cancer the figures were 17 per cent in men and four per cent in women. It also was responsible for five per cent of breast cancer in women.
Cancer experts remark that data of this kind make alcohol “one of the most carcinogenic products in common use”. There is, of course, a correlation between the amount of alcohol drunk and the incidence of cancer, and major risk is associated with intake above the recommended levels (two units of alcohol a day for men and one unit for women).
However, it is disturbing to note that no level is completely exempt of risk, and the only way to avoid getting alcohol-induced cancer is to stop drinking alcohol altogether. This is particularly important in those situations where there is a history of cancer in the family.
The only encouraging finding in this study is that those who have stopped drinking show some reduction in the expected increased cancer incidence.
Epidemiologists have long been looking for reasons why cancer incidence has hit the roof over recent years. Cancer-producing agents (carcinogens) were sought and sometimes found, involving workers in such situations as asbestos, or chemical industries, for example. These accounted for a very small number of cases of cancer overall.
We have also blamed the high cancer incidence on longevity: the longer we live the higher the chances of our getting cancer. And there is no doubt that over the past 50 to 60 years, average life expectancy has risen to about 80 years of age in most of Europe.
None of these explanations have been completely satisfactory. The finding that an agent of such widespread distribution as alcohol is a causative agent, even in those indulging in small doses, has raised justifiable alarms.
Particularly worrying is the growing use of excessive amounts of alcohol by young people from an early age, with the obvious suggestion that alcohol-induced cancer is likely to become an even more important culprit in the future.