Cutting back on red meat does not reduce cancer risk – study

Cutting down on bacon and sausages is unlikely to have any impact on the risk of contracting cancer, according to new research from Canada.

The findings have shed a welcome new perspective on the debate about red meat and cancer, using the same evidence as previous studies but interpreting it in a different way.

The research challenges the assumptions made in recent high profile reports on the subject, including the World Health Organisation’s International Agency for Research on Cancer, which concluded processed meats do cause cancer. It also said red meats were ‘probably carcinogenic’ but there was limited evidence.

This is reflected in current official Government advice, which advises anyone who eats more than 90g of red or processed meat a day to cut down to 70g a day, the equivalent of two rashers of bacon.

The researchers – led by Dalhousie University and McMaster University in Canada – reviewed the same evidence others have looked at before and their findings, published in Annals of Internal Medicine, were not dissimilar.

They concluded that if 1,000 people cut out three portions of red or processed meat every week for:

• a lifetime, there would be seven fewer deaths from cancer
• 11 years, there would be four fewer deaths from heart disease

And if every week for 11 years, 1,000 people cut out three portions of:

• red meat, there would be six fewer cases of type 2 diabetes
• processed meat, there would be 12 fewer cases of type 2 diabetes

However, researchers interpreted the findings in a very different way, stressing the point that for individuals the risks are ‘not that big’. The said the evidence is so weak, they could not be sure the risks were real.

Speaking to BBC News, one of the researchers, associate professor Bradley Johnston, said: “The right choice for the majority of people, but not everyone, is to continue their meat consumption. We’re not saying there is no risk, we’re saying there is only low-certainty evidence of a very small reduction of cancer and other adverse health consequences of reducing red meat consumption.”

However, there appears to be little prospect of any change in official Government advice on the back of this research. Public Health England officials told BBC News they had no intention of reviewing their advice on limiting meat intake.

Reaction

Nick Allen, CEO of the British Meat Processors Association said: ‘This report highlights a gap in the evidence from scientific studies. Instead of flawed observational studies, dietary advice should be based on higher quality randomised control trials that compare differing but strictly controlled amounts of red meat consumption over a long time frame.

“To date, only 12 have been carried out, none of which offer any conclusive or even consistent evidence.

“It raises questions about how dietary advice is communicated to people. Official guidelines based on evidence with ‘low to very low certainty’ coupled with headline-grabbing but unsubstantiated claims in the media and on social media are not helpful.

“It prompts some people to make drastic changes to their diet without having an accurate picture of how this will affect their health. These people run the risk of inadvertently substituting a healthy, balanced diet with one that lacks essential nutrients and has the opposite effect on their health.”

Liam Byrne, Head of Meat Marketing at AHDB, said: “It is heartening to have a positive report about red meat – and one which is being so widely welcomed by academics as being robust. It confirms what we in the industry all know – red meat remains an important part of a balanced diet.

“This is a shot in the arm for our producers, processors and butchers who have been besieged by negativity around red meat for so long, based on half-truths and ill-informed opinion.

“The study shows evidence suggesting red meat can have an adverse effect on health is weak, at best, and certainly not strong enough to confidently suggest lifestyle changes for those perceived to eat more than the recommended weekly amount of 500g. Sadly, we continue to see those with an alternative agenda crying foul and expressing public outrage at this report.

“The report shines a welcome light on how people are being encouraged to cut out red meat or dramatically reduce consumption based on assumptions from associative studies rather than actual scientific research. The studies which show the benefits red meat bring to the diet for all ages, are too often ignored.

“More than 99 per cent of households in the UK enjoy red meat, according to Kantar, and this report should give them the permission to continue to enjoy red meat as part of a healthy balanced diet.”

The research has divided opinion within the scientific community.

Prof David Spiegelhalter, Chair, Winton Centre for Risk and Evidence Communication, University of Cambridge, said: “This rigorous, even ruthless, review does not find good evidence of important health benefits from reducing meat consumption.

“In fact, it does not find any good evidence at all – all the studies are ranked as providing ‘low’ or ‘very low’ certainty.  We might expect even more controversy when this group turn their attention to other ‘risky’ things we consume.

“In contrast to their conclusions about health, I think we can be confident that reduction in meat consumption would benefit the planet.”

Prof Tim Key, Professor of Epidemiology & Deputy Director of the Cancer Epidemiology Unit, University of Oxford, said recent estimates suggest over 5,000 people in the UK develop bowel cancer due to the consumption of processed meat each year, which is why the government recommends that people keep their total intake of red and processed meat to no more than about 70 g per day.

“There’s substantial evidence that processed meat can cause bowel cancer – so much so that the World Health Organization has classified it as carcinogenic since 2015,” he said.

“Today’s new publication reports results essentially identical to the existing evidence, but describes the impact very differently, contradicting the general consensus among cancer research experts.

“The authors here have found the same evidence of an effect but they think it is so modest that it isn’t worth recommending we do anything about it.”