Does drinking milk increase the chance of cancer?

We put Patrick's question to Kat Arney, and also asked about the recent news of red meat's status as cancer-causer... Chris - Do you eat sausages and bacon? His question is, "Does drinking milk increase the chance of cancer?" Should I be avoiding bacon and sausages or should I just take a reality check and probably, the risk is relatively light?

Kat - Okay, so I'm going to put my work hat on here because from my data, I work for Cancer Research UK and we do have a lot to say about diet and cancer risk and there have been a lot of studies done. So, there was always stuff in the news recently about, "red meat is as bad as smoking and it's all really terrible!" When you look closely at it, there's a really important difference when you're looking at components of the diet and cancer risk, about the strength of the evidence versus the size of the risk. Now, all the red meat stories came about because IARC, the International Agency for Research on Cancer which is part of the World Health Organisation, they basically said that there is strong enough evidence on red and processed to put it in the same category as smoking in terms of it causing cancer or increasing the risk of cancer in humans. Now, this doesn't mean that a sausage is as bad as smoking a fag. This isn't the same thing at all.

Chris - So, what about if you smoke the sausage?

Kat - Well, smoked sausages are possibly worse than normal sausages. But basically, we know for example that certain amounts that you smoke increase your risk by certain amounts which is much bigger than the increase in risk in eating certain amounts of red and processed meat. So basically, it's about the strength of the evidence is very strong. We definitely know that if you eat certain amounts of red and processed meat, you will increase your cancer risk by a certain amount. The more you eat, the bigger your risk, the less red and processed meat you eat, the lower your risk. Chris - The fact is there are billions of cigarettes being smoked all around the world every day.

Kat - Exactly. I mean certainly, your risk from being a regular smoker is going to be a bigger cancer risk than being a regular meat eater but there will be a risk associated with eating red and processed meat.

Chris - And does milk come under red and processed? Is the same sort of envelope?

Kat - So basically, the evidence on milk and dairy increasing cancer risk is very, very mixed. It's kind of a bit of an internet folklore that dairy is bad for you and it will increase your risk of cancer, particularly breast cancer. The studies have been very mixed on it so some have shown that eating lots of milk and dairy increases your cancer risk. Others have shown that it decreases your cancer risk. So certainly, the weight of evidence there is all over the place. But more broadly, when you're talking about diet and cancer, we don't just eat one thing. You just don't live on steak or on cabbage. You need to have a balanced diet that's kind of rich in fruit and vegetables, less red and processed meat, if you're a meat eater, more chicken and fish. It's risk. It's not a yes, no, black, white. The more of one thing you do, the more it will increase your risk, the more something else you do, the more it will decrease your risk. It's the same with alcohol. The only thing that's really kind of really, really bad for you is basically smoking, so don't do that.