Processed meats – such as bacon, sausages and ham – do cause cancer, according to the World Health Organization (WHO).

Its report said 50g of processed meat a day – less than two slices of bacon – increased the chance of developing colorectal cancer by 18%.

Meanwhile, it said red meats were “probably carcinogenic” but there was limited evidence.

The WHO did stress that meat also had health benefits.

Cancer Research UK said this was a reason to cut down rather than give up red and processed meats.

And added that an occasional bacon sandwich would do little harm.

What is processed meat?

Processed meat has been modified to either extend its shelf life or change the taste and the main methods are smoking, curing, or adding salt or preservatives.

Simply putting beef through a mincer does not mean the resulting mince is “processed” unless it is modified further.

Processed meat includes bacon, sausages, hot dogs, salami, corned beef, beef jerky and ham as well as canned meat and meat-based sauces.

It is the chemicals involved in the processing which could be increasing the risk of cancer. High temperature cooking, such as on a barbeque, can also create carcinogenic chemicals.

In the UK, around six out of every 100 people get bowel cancer at some point in their lives.

If they were all had an extra 50g of bacon a day for the rest of their lives then the risk would increase by 18% to around seven in 100 people getting bowel cancer.

“So that’s one extra case of bowel cancer in all those 100 lifetime bacon-eaters,” argued Sir David Spiegelhalter, a risk professor from the University of Cambridge.