Cancer and the bacon sarnie

When Professor Martin Wiseman published his study on cancer this month, he had no intention of demonising the bacon sarnie. Here, he sets the record straight

When I saw the headline in the Daily Express about "food fascists", I wondered what the story was about. On closer examination, I realised that they were actually talking about my colleagues and me.

The subject of the writer's ire was the World Cancer Research Fund report on cancer prevention, which we published this month and which, in my role as project director, has taken some six years.

While the Express headline might have been the extreme, even the general press coverage seemed to give the impression that our supposed war on the humble bacon butty was the greatest threat to the British way of life in living memory.

As someone not used to being in the public eye, I found this rather bemusing. I wonder whether the people have an image of us as a bunch of puritans who want to ban bacon and who consume nothing but brown rice, water and vegetables in a desperate attempt to live to 110.

The truth, I'm afraid, is rather more prosaic. Like many people, I enjoy good food and wine and when it comes to healthy living, including reducing cancer risk, there are areas where I could do better.

But this report was never about wagging the finger at people, nor about making them feel scared or guilty about the fact that their lifestyle is not as healthy as possible. We have never attempted to tell people how they should live. If my next-door neighbours want to have bacon for breakfast, lunch and dinner, then that's up to them. What is important is that any decisions they make should be informed ones. Doctors have to give people information, some of it unwelcome, to help them decide between two treatment options, for example. But whether people like the facts or not, they need them if they are going to be able to make an informed choice. Our report has given them those facts.

One of the aims of the report was to fill an information gap. New research is published all the time on what increases and decreases cancer risk and, naturally, some of the evidence from these individual studies appears to be contradictory. Even when the evidence doesn't contradict, it is impossible for the general public to know how much weight to give each study. Because of this, people have become cynical about the sheer volume of cancer prevention advice and confused about what they can do to reduce their own risk. Our report provides an expert independent overview of all the facts.

The panel looked at all the scientific evidence on how diet, physical activity and weight affect cancer risk since records began, and came up with 10 practical steps that people can follow if they are worried about cancer. And because our report is the most comprehensive study of the evidence on this topic ever done, the public can be confident that our recommendations represent the best advice available, anywhere in the world.

This is good news – people can take positive steps to stay healthier for longer. It is information that can empower the public, so I have been slightly surprised by some of the negative comments. But it's worth remembering that when the first studies linked smoking with cancer back in the 1950s, there was a similar reaction. Things are not going to change overnight. But I'm sure that, as the battle against smoking is beginning to be won today, the area of lifestyle and cancer will become an increasingly important issue over the next few years.

We are not saying that this report is the final answer. If it were, then there wouldn't be any point in doing more research into the link between lifestyle and cancer. But we believe that, because of the unprecedented rigour of the process we used, our report is as close to the truth about lifestyle and cancer prevention as it is possible to get at this point.

However, it is important to emphasise that while our recommendations are based on the best science available, they are recommendations, not commandments. The whole point of them is to give people the information they need to make their everyday choices informed ones.

Let's take the bacon issue as an example. We are not saying for one moment that if someone eats bacon every day, then they will go on to develop bowel cancer. But what we are saying – and the science is quite clear on this – is that, all other things being equal, someone who eats bacon every day is more likely to develop bowel cancer than someone who does not eat processed meat at all. A person must make an individual judgement on whether their enjoyment of bacon is such that it is worth a small increase in their bowel-cancer risk.

And it's worth bearing in mind that while the effect on risk of each individual factor – like processed meat or alcohol – might be relatively small, these risks add up. In fact, we and other independent experts estimate that about one-third of cancer cases can be attributed to factors relating to diet, weight and physical activity. When you consider that smoking also accounts for about one-third of cases, it's clear that people can make a big difference to their cancer risk. Of course, for the majority of British adults who now do not smoke, following our recommendations is probably the most important step they can take to help reduce their lifelong risk of cancer and prolong their healthy years.

Another point about the media coverage of our report is that it has presented our recommendations as something that must be either followed or ignored, and this is neither correct nor realistic. The recommendations represent goals that people can aim for, but they are certainly not a case of all or nothing. The evidence is clear that people can reduce their cancer risk by making even modest changes. If it is too difficult to cut out processed meats completely, then cutting down – say, from four bacon sandwiches a week to two – can still be valuable. So can being physically active for 10 minutes a day instead of not at all.

This is a message that the World Cancer Research Fund will be working hard to get across in the coming months. But even though some of the publicity has not been perfect, the amount of coverage we achieved around the world has been very gratifying.

For a long time now, the science has been clear that diet and physical activity are closely linked to cancer risk. But while the general public knows about the links between smoking and cancer, and being overweight and diabetes or heart disease, there has never been the same awareness about the link between lifestyle and cancer. Thanks to the media coverage over the past couple of weeks, that message seems to be getting through. The important thing is that we get the positive message across that cancer is not just a question of fate, and that people can choose to make changes to their lives today that can reduce their risk of developing cancer tomorrow.

Martin Wiseman is project director for the World Cancer Research Fund Expert Report