‘Too much’ nitrite-cured meat brings clear risk of cancer, say scientists

A leading scientist has urged ministers to ban the use of nitrites in food after research highlighted the "clear" risk of developing cancer from eating processed meat such as bacon and ham too often.

The study by scientists from Queen's University Belfast found that mice fed a diet of processed meat containing the chemicals, which are used to cure bacon and give it its distinctive pink colour, developed 75% more cancerous tumours than mice fed nitrite-free pork.

It also found that mice fed nitrite-cured pork developed 82% more tumours in the bowel than the control group.

Among those who conducted the research trial, in which mice were fed a diet of 15% nitrite-containing processed meat, was Prof Chris Elliott OBE, who led the government's investigation into the horsemeat scandal of 2013.

Elliot called on the government to change its position on nitrites in processed meat, in light of the study. "The results of this new study make the cancer risk associated with nitrite-cured meat even clearer. The everyday consumption of nitrite-containing bacon and ham poses a very real risk to public health."

The study found that mice fed a similar amount of nitrite-free pork did not have an increase in tumours, further demonstrating that consumption of the chemicals had a substantial impact on cancer risk.

Dr Brian Green, one of the authors of the report, which is published in the journal Nature, said: "The results from our study clearly show that not all processed meats carry the same risk of cancer and that the consumption of nitrite-containing processed meat exacerbates the development of cancerous tumours."

About 90% of bacon sold in Britain is thought to contain nitrites, which previous research studies have linked to the development of bowel, breast and prostate cancers. The chemical is also used in some continental meat products such as frankfurter sausages.

Although a diet of 15% nitrite-containing processed meat is a relatively high intake, the researchers suggested that their findings showed that consumption of even lower quantities could still increase the risk of cancer.

The European Food Safety Authority recently published an updated draft opinion that suggested levels of nitrites in food could indicate a health concern.

Meanwhile, the French government has committed to eliminate the use of nitrites in food production where possible, following the publication of a study by the national health agency, in July, that concluded that the chemicals increased the risk of cancer.

Elliot, who is among a group of scientists, MPs and peers, who are urging UK ministers to ban the use of the chemicals in processed meat, added: "The European Food Safety Authority and the French government are following the facts. It's time the UK government did too."

Another member of the group calling for a ban, the Conservative MP Daniel Poulter, a former health minister under David Cameron, who is also a practising NHS doctor, added: "With the NHS facing ever increasing pressure, especially for cancer treatment, prevention has never been more vital for our health system.

"I urge ministers to review the latest evidence on nitrites and act now in the face of this potential health risk."

The SNP's health and care spokesman, Martyn Day, said: "By rejecting legislation to ban these potentially dangerous nitrites the UK government is failing to keep their promise to maintain high food standards after Brexit.

Rick Mumford, head of science, evidence and research at the Food Standards Agency, said the new study would be evaluated.

"Nitrates are important preservatives which hinder the growth of harmful organisms, in particular the bacteria responsible for botulism - which can be life-threatening," he said.

"They are regulated as a food additive and, before authorisation, must pass a robust safety assessment.

"Because of the possible link between eating too much red and processed meats and bowel cancer, the government recommends limiting consumption of these products to 70g per day."

Nitrites have been identified by the World Health Organization as a cause of 32,000 bowel cancer cases a year.