Even small amounts of red and processed meat – such as a bacon bacon per day – may increase the risk of bowel cancer, according to the research.
The latest study led by Oxford University and funded by Cancer Research UK adds to the evidence, including the World Health Organization, that eating red meat can be harmful.
But how much is the risk? And how much is it?
Here's what you need to know.
What the study found:
The researchers analyzed data from nearly half a million people involved in the British study Biobank.
During the six years of their study, they found that 2,609 people developed colon cancer.
- Eating three bacon slides per day, not just one, can increase the risk of colon cancer by 20%
- For every 10,000 people in the study who ate 21g per day of red and processed meat 40 were diagnosed with colon cancer
- The comparative figure for those who ate 76 grams per day was 48
According to the NHS, 76 g of cooked red meat is equivalent to about half a beef steak of 8oz. A piece of ham or raspberry from bacon is about 23 gr of processed meat,
How much too much?
It's not clear. Research on Cancer UK says that 5,400 of the 41,804 cases of colon cancer seen every year in the UK could be prevented if people did not eat processed meat at all.
But the charity acknowledges that smoking is a much higher risk, causing 54,300 cancer cases each year.
Public health England says that many people eat too much red and processed meat from their research.
And experts advise people who eat a lot to find ways to reduce.
The Department of Health advises anyone who eats more than 90 gr of red and processed meat daily to be reduced to 70 gr.
Are some all right?
The NHS guidelines say there are some benefits of red meat – for example, iron and protein content – that must be balanced against potential risks.
People can still eat meat and be healthy.
What makes it risky?
Processed meat – including bacon, sausages, hot dogs, salami – is modified either to prolong the shelf life or to change the taste – the main methods are smoking, treating or adding salt or preservatives.
The chemicals involved in the processing are thought to increase the risk of cancer. High-temperature cooking, such as barbecue, can also create carcinogenic chemicals.
When it comes to red meat such as beef, lamb and pork, there are suggestions that one of the proteins (giving it a red color) can damage the stomach when it is destroyed.
But experts are still trying to fully understand the relationship.
What do experts say?
Professor Gunter Kunle, of the University of Reading, described the study as a very thorough analysis of the link between intake of meat and colon (also known as colorectal).
He said: "The results confirm earlier findings that both red and processed meat consumption increase the risk of colorectal cancer.
"The increase in the risk of approximately 20% of the 50g increase in red and processed meat intake is in line with what has been previously reported and confirms these findings.
"The study also shows that dietary fiber reduces the risk of colorectal cancer. Increased hair consumption, as shown in this study, will be significantly more beneficial."
Kerry Rickston, from the Council for Meat Meat, an industry-funded body, said: "Red meat provides valuable nutrients such as proteins, iron, zinc, vitamin D and B vitamins."
She said it is known that "many factors of lifestyle have a significant impact on the risk of colon cancer, especially age, genetics, lack of dietary fiber, inactivity and high alcohol consumption."