In October, the International Agency for Research on Cancer (IARC) released a controversial statement declaring that the consumption of processed meats can increase an individual’s risk of cancer by up to 18 per cent. This statistic relates to individuals consuming around 50 grams of processed meat per day. Their research confirms the findings of a 2002 World Health Organisation (WHO) report, entitled ‘Diet, nutrition, and the prevention of chronic diseases’, which advised people to eat processed meats only in moderation.
Meat is ‘processed’ when it has had chemicals added to it, either to alter taste or preserve it. This includes: sausages, bacon and ham, but not mince or fresh steak. Currently, around six in 100 people will get bowel cancer at some point in their lives. It is argued by David Spiegelhatler, a professor of risk from the University of Cambridge, that increasing this risk by 18 per cent only actually equates to seven (one extra person) in 100 getting cancer. Nevertheless, small individual risk can have massive implications on the grander scale of public health. These findings cannot be ignored.
It is unclear exactly how processed meats contribute to an increased risk of cancer. The most widely accepted theory is that the chemicals involved in meat processing, namely nitrile preservatives, are to blame. When food is digested, these preservatives can be broken down into N-nitroso compounds which damage cells lining the bowel. In turn, other cells replicate in order to compensate for the loss. It is during this process that DNA mutations (the initial step of cancer) are most likely to occur. A group of researchers from the Netherlands have suggested that bacterial flora in the gut also play a pivotal role in causing damage. Although the precise mechanism of action is unknown, the growing body of evidence suggesting that processed meats are carcinogenic is almost incontrovertible. In this case, the IARC used over 800 studies to inform their final statements, asserting that there is, “sufficient evidence in humans that the consumption of processed meat causes colorectal cancer.”
Perhaps rather predictably, the international reaction to these findings has been one of dismay. John, a butcher at Smithfield (the largest meat market in the UK, which has been running at the same site for around 800 years), when speaking to The Guardian, declared the findings to be ‘scaremongering.’ In countries like Austria, where the average citizen consumes over 65kg of meat a year, responses have been rather more vehement. Andrä Rupprechter, the Austrian Minister for Food and Agriculture, called the IARC report a ‘farce’, later posting a jaunty picture of himself on Twitter eating cured meats in protest. Echoing an earlier statement by his German counterpart, Rupprechter went on to say: “Placing ham on the same level as asbestos is outrageous nonsense and only serves to unsettle people.”
It is worth remembering that the IARC works to identify hazards rather than to assess the level of risk. Just because tobacco and processed meat have been placed in the same ‘Group 1: causes cancer’ category, does not mean that they have equal potential to cause disease.
If no one smoked, 64,500 occurrences of cancers could be prevented in the UK every year. By comparison, only 8,800 would be stopped if people completely eliminated red and processed meat from their diets, according to the findings of this study. Still a substantial number, but surely a more accurate reflection of the risk incurred. Moreover, meat is a good source of essential dietary nutrients such as protein and iron.
Although the IARC findings may hopefully inspire very regular meat eaters to reduce their intake, they by no means suggest that red meat should be eliminated from the diet completely. So the Austrians can sleep easy; expert advice on meat remains somewhat unchanged – it is simply all about moderation.
Image: Böhringer Friedrich