Can you prevent cancer? Yes, you can prevent some types of cancer, some of the time. How is that for hedging your beats? I could be a politician!
Many people think that getting cancer is solely down to fate. Some people blame faulty genes, after all, you can’t choose your parents. Many people think getting cancer is down to bad luck. Some people blame new technology and cocktails of chemicals in our environment.
If all that is true, why bother eating a healthy diet or exercising? After all, we all know people who ate healthy food or exercised regularly and still developed cancer. Life clearly isn’t fair.
I’m writing about this (again), because there have been two recent news articles on the subject. The first is a study by the World Cancer Research Fund saying that 80, 000 cases of cancer in the UK could be prevented, EVERY year by eating healthily and exercising regularly (even more cases of cancer could be prevented if everyone stopped smoking). They estimate that this could prevent 19,000 cases of breast cancer and 16,000 cases of bowel cancer.
Does that mean all cases of breast cancer are caused by diet? No. Some (a small percentage about 10 %) are caused by a specific genetic fault. For the rest of cases, we still don’t know what triggers them, which is why we need more research. The same is true for bowel cancer, not all cases of bowel cancer are caused by a poor diet and like breast cancer a small number are inherited. This doesn’t mean cancer prevention isn’t important, it is, but it’s not perfect.
There is a post on Science Based Medicine called “Cancer prevention: The forgotten stepchild of cancer research?” which was prompted by an article in the New York Times – Medicines to deter some cancers are not taken, in which some scientists argue diet doesn’t have as big a role as we would like to think.
What do I think?
I think if you know someone who has developed cancer despite living a very healthy lifestyle then it can be very hard to accept that improving your diet and exercising can will stop you getting cancer.
As a scientist, I have read a lot of clinical trials and research studies. Many people tend to dismiss this research, saying “oh the scientists will change their minds next week” but we do learn from research and it is worth doing. There is an article in the New York times with one of the best ways of explaining clinical research I have ever come across called “Impressive science meets unimpressed patient” by Dr Abigail Zucker, please read it (it’s far better than my summary, which follows).
The basic idea is that doctors looking at a clinical trial can look down on two giant fields full off people. One field is full of the keen, keep fit freaks that excercise. The other is full of people that are lazy and don’t do so much. From their perch in the sky doctors can see that over time, 30-40 years the exercising people do better. However, if you’re in the “lazy club” and you are healthy and your best friend is in the “excercise club” and develops cancer then it is hard to believe that, overall excercise is good for you (even though it is).
I believe that a healthy diet and regular excercise will prevent a lot of cancers (maybe as many as 40 %). I believe that some people will inherit cancer regardless of what they eat, this number is smaller (maybe nearer 10 %). That means, for another 50 % of cancer we don’t know their cause. I’m not convinced that we are causing cancer by a deadly cocktail of chemicals, read Making Sense of Chemical Stories and Science for Celebrities to learn more. I think we need more research and I think we will find the reasons behind these cancers, just as we have discovered the bacteria and viruses that cause diseases like TB, HIV and smallpox.
The bottom line? I don’t believe wearing a seat belt will save you from all car accidents, I don’t believe a healthy diet will prevent all cancers but I DO wear a seat belt when I am in a car and I DO try and eat well. Until we know more that is all I can do.
What do you think? Please feel free to leave a comment below.