Thousands of schools are serving pupils meals that includes meat that has been cured with chemicals shown to increase the risk of cancer.
Local education authorities (LEAs) across England and Wales have said that some or all of the schools in their area are using meat that has been treated with either nitrites or nitrates.
They are doing so even though there is evidence that both chemicals, which are commonly used as preservatives and to make bacon and ham look pink, can be carcinogenic. Some scientists and politicians are calling for them to be banned in meat production.
The disclosure has prompted concern that children and young people are being exposed to “hidden health risks” as a result of eating the food served in school canteens.
“These extremely worrying findings make clear that children are being exposed to the potential health risks posed by nitrites from a young age in schools across the country,” said Prof Chris Elliott of Queen’s University Belfast, who is an expert in the role chemicals play in food production.
In response to freedom of information (FoI) requests, 21 LEAs said all their local schools – more than 2,000 in total – were serving meat that may contain nitrates or nitrites.
Another 53 LEAs said that some of their schools were doing so. Only nine of the 173 LEAs surveyed said categorically that none of their schools were using such meat.
“These figures suggest that children in a very large number of schools across the country are exposed to unnecessary nitrites, potentially frequently,” said Elliott. “This investigation makes clear that the presence of cancer-causing nitrites in food is ignored by decision-makers, probably to save a few pennies per meal.”
However, 85 LEAs – almost half those asked – said that they did not hold information that would allow them to respond to the request, so the picture across the two countries was incomplete.
The International Agency for Research on Cancer, the World Health Organization’s cancer arm, has been warning since 2015 that processed meat – such as bacon, sausages and hotdogs – could be as carcinogenic as tobacco and asbestos.
Earlier this year the European Food Safety Agency (EFSA) said that it had concluded after an investigation that the levels of nitrites found in food on the continent “raise a health concern”.
Nitrites have been identified as a factor that increases the risk of developing bowel cancer. The disease has been rising among younger adults (under-55s) in the United States – where they made up 20% of cases in 2019, up from 11% in 1995 – and Australia, although there is as yet no data showing a similar trend in the UK.
Research published in a leading American medical journal in 2021 predicted that bowel (also known as colorectal) cancer will be the leading cause of death from cancer among 20- to 49-year-olds by 2040.
“With rates of bowel cancer in young people the highest on record, the very real danger posed by nitrites is clearer than ever,” said Elliott. He reiterated his demand – which is backed by other scientists and a cross-party group of MPs and peers – for the UK government to ban the use of nitrites in meat processing.
A study published in January also linked nitrites to a higher risk of developing type 2 diabetes.
Lady Ritchie, a Labour peer, said a ban was “well overdue”. “Parents have the right to expect their children are kept safe in schools, and that includes being free from exposure to the risk of cancer or diabetes in the food they eat,” she added.
The FoI exercise was undertaken by Finnebrogue, a Northern Irish food firm that launched the UK’s first brand of nitrite-free bacon – Better Naked – in 2018.
Jago Pearson, the company’s chief strategy officer, said it welcomed other food producers, including Waitrose, Morrisons and Marks & Spencer, introducing similar products “because this can only help improve the health of the nation”.
Despite growing concerns, ministers appear unlikely to ban nitrites or nitrates.
Thomas Vincent, the head of chemical safety at the Food Standards Agency, said: “Nitrates and nitrites are important preservatives which hinder the growth of harmful organisms, in particular the bacteria responsible for botulism – which can be life-threatening.
“They are regulated as a food additive and have undergone a safety assessment prior to being authorised. The safety of food additives is kept under review.”
The Department for Education declined to comment.
Nitrites v nitrates
Nitrates (NO3) and nitrites (NO2) are chemicals that are used widely as preservatives in processed meats. Nitrates are compounds that are found everywhere: in water, plants, soil and even in raw meat.
Alone, they are not a health risk. It is the process of adding nitrites to meat, cooking that meat and then ingesting it that triggers a chemical reaction that produces nitrosamines, or N-nitroso compounds. These nitrosamines are carcinogenic.
Consumers have become accustomed to bacon and ham that is pink in appearance. Historically, bacon and ham produced without nitrites was grey in appearance and had a shorter shelf life.
However, new technologies using natural Mediterranean fruit extracts can help to keep the meat pink and create nitrite-free bacon and ham that has a similar shelf life to the nitrite-cured alternatives.
• This article was amended on 4 September 2023. An earlier version said rates of bowel cancer among younger adults in the US had risen from 11% in 1995 to 20% in 2019. To clarify, those figures were for the proportion of cases that occurred in younger adults, and that age bracket was defined in the study as under-55s, not under-50s.
