Question: Newspapers say that eating bacon can cause cancer. Is that true?

David Nunan answered on 10 Nov 2015:

Hi Izzy,

That’s a brilliant question, you saw the headlines about this then!

Well the headline was actually from a good study that looked at people who did not have cancer and then asked them how much meat do they eat. They then watched them over a long period of time to see how many of them got cancer. They compared the number of people who ate lots of red meat with those who ate less or no red meat to see how many got cancer or not.

This type of study is called an observational or cohort study. It’s not the best type of study to answer the question”does red meat cause cancer”. The best study for this question would be a randomised controlled trial because these are the best types of studies on questions to show if something causes something else or not. It would involve giving one group of people red meat to eat, and another group of people not being allowed to eat red meat. The only difference in their diet would have to be red meat.

However, you can see that this would be very difficult to do in real life unless you stuck people in a lab. That is why a lot of the research in this area is done in animals because we can control everything they eat within a laboratory setting. There’s a nice video here which helps explain the differences between different studies: https://www.youtube.com/watch?v=GUpd2HJHUt8

So coming back to what the study found. They found that in people who said they ate more processed red meat (so bacon, sausage, ham), then their risk of cancer was higher than those who ate less processed meat. The risk of developing cancer in people who ate more processed red meat was about 18% higher. This figure sounds high but your own individual risk of developing cancer is quite low, particular at your age, and is more likely to be less than 1%. Plus there may be other factors that caused patients to have more cancer that were not picked up by the study so it’s hard to say for sure.

The study did not find strong evidence of a link between cancer and eating red meat, probably because they didn’t have enough data.

But it’s also important to remember that red meat also has some nutrients that are very good for you like vitamin B12 and iron (important for helping your blood carry oxygen around your body!).

So the key thing is to not worry too much about the risks of eating red meat. Having a balanced diet with a mix of real foods is best. A real food is one where nothing (or very little) has been added to it. One way to tell is look at the ingredients list of any packet of food you buy (lose fruit and veg don’t count obviously!), if there are more than 4 or 5 ingredients then it’s probably not a ‘real’ or ‘whole’ food but most likely a processed food. You want to less of the processed foods but you don’t have to cut them out completely. Plus treats such as sweets and cakes are also ok but again go easy on them!