Four out of five NHS hospital trusts are serving up bacon and ham products that have been linked to colorectal cancer

Meat cured with chemicals that have been blamed for causing certain types of cancer are on the hospital menus at more than four-fifths of NHS trusts, according to new research.

The revelation has triggered cross-party calls for the NHS to take action.

Data obtained via a Freedom of Information request reveals that 113 NHS English foundation trusts include nitrite-cured bacon and ham in the meals they offer patients. Of these, 12 admit to offering patients meat containing potassium nitrite.

Just 14% of trusts in England are nitrite-free, while the remaining 5% either refused to disclose the contents of their patient meals or failed to respond to the request for information.

“It is concerning that so many hospital meals contain nitrite-cured meat, given the wealth of evidence that has been published linking these chemicals to colorectal cancer,” said Conservative MP Sir David Amess, who chairs the cross-party parliamentary group on food and health.

“It is the responsibility of our NHS to lead by example and so I would urge these foundation trusts to remove nitrites from their menus as soon as possible. With the development of safer alternatives, it is clear nitrites don’t need to be added to pork anymore to make our bacon and ham,” Amess said.

Labour’s former shadow environment secretary, Kerry McCarthy MP, described the figures as extraordinary: “Serious questions must be asked of these NHS foundation trusts. It cannot be acceptable for patients to be admitted to hospital, only to be fed cancer-causing meals while they are in there.

“With the advent of safer nitrite-free alternatives it is about time these trusts and the government move to remove nitrites from their menus at the earliest possible opportunity.”

In 2015, the World Health Organisation (WHO) linked 34,000 cases of bowel cancer every year to the consumption of nitrite-cured processed meats. Concerns have seen some food producers, such as Finnebrogue and Nestlé, start selling nitrite-free ham and bacon products. Many of the NHS groups that use meat treated with nitrites claim the chemicals are essential to protect against botulism in food products. However, an internal report produced for the British Meat Processors Association – seen by the Observer – found that nitrites appeared to be ineffective in preventing the spread of clostridium botulinum bacteria.

It has now emerged that the European commissioner responsible for health and food safety, Vytenis Andriukaitis, has ordered a review of the levels at which nitrites are legally permitted to be added to meat. The intervention was requested by Professor Denis Corpet, who co-authored a WHO report on nitrites, and wrote to Andriukaitis, and health secretary Matt Hancock, urging them to intervene.