Scientists warn that just two portions a week increases the risk by almost a fifth
Scientists from Oxford University said that eating four portions of red meat could make you 42 per cent more likely to develop the disease.
And just two portions a week increased the risk by almost a fifth, they said.
Just last week, the World Health Organisation warned that bacon, ham and sausages ranked alongside cigarettes as a major cause of cancer.
A report said each 50g of processed meat a day – the equivalent of one sausage, or less than two slices of bacon – increased the chance of developing bowel cancer by 18 per cent.
In the latest study, Prof Tim Key and Dr Kathryn Bradbury looked at the records of 500,008 middle-aged British men and women aged 40 to 69, tracking their meat consumption for a four year period, according to the Daily Mail.
Over that time, 1,503 of the participants developed bowel cancer.
The study found that those who had had eaten red or processed meat four times a week were 42 per cent more at risk than those who had it once or not at all.
And those who ate it at least twice a week were 18 per cent more at risk compared with vegetarians.
Professor Key, who is due to present the findings at the National Cancer Research Institute conference in Liverpool on Tuesday, said: “People need to be aware of the risks and make modest changes if necessary.
“Eating things other than meat seems to be the sensible approach. So eating plant-based proteins such as beans, chicken or fish.”
The scientists based their analysis on average portion sizes, which equate to two rashers of bacon, two slices of ham or one sausage.
But a quarter pounder burger is 200g – nearly three times this level – while a 10oz steak from a restaurant is equivalent to 284g, or more than four portions.
The study also found that eating large amounts of fibre did not significantly lower the risk of developing bowel cancer.
Bowel cancer is the second biggest cancer killer in the UK, leading to 16,000 deaths a year.
Mark Flannagan, chief executive of Beating Bowel Cancer, said: “We must not underestimate the importance of diet in reducing your risk of bowel cancer.
“The evidence suggests there is a strong link between red and processed meat and bowel cancer, so we recommend eating both in moderation.”
Current NHS advice is to limit intake of all meats to 70g a day, but there is no specific recommended limit for cured and processed meats.
The average person in the UK has 2.5oz (70g) meat a day 3oz (88g) among men, 2oz (52g) among women) but one in three people have more than 3.5oz (100g) a day, research suggests.
The new advice from WHO suggests 50g of processed meat is enough to significantly raise bowel cancer risk, by 18 per cent.