Worrying new research has linked a number of preservatives found in everything from cured meats to toothpastes could be linked to an increased risk of cancer. The potentially carcinogenic ingredients were found in a new study published in the European Medical Journal (EMJ), which also flagged the alarming preservatives in salad dressings, ketchup and mustard. 

French scientists took the data from a sample of over 100,000 people, 80 per cent of whom were women, with an average age of 42. Participants were monitored for their consumption of preservatives using a 24-hour dietary record completed over 7.5 years. 

The people taking part in the research were studied from 2009 to 2023 and by the time the research was complete around 4,000 had been diagnosed with cancer, including breast, prostate and colorectal.

According to the EMJ, researchers found “the strongest and most consistent associations were observed for breast cancer”. It added: “Higher intakes of potassium sorbate, potassium metabisulphite, potassium nitrate and sodium erythorbate were each linked to a significantly increased risk.

“Women with the highest exposure to these preservatives had between a 20 and 26 per cent higher risk of breast cancer compared with those with the lowest exposure.

The EMJ said the study also identified “some associations between preservative intake and overall cancer risk” but that findings related to prostate and colorectal cancers “were less consistent”.

The publication said in a statement: “The researchers conclude that if these findings are confirmed by further studies, they could prompt European and international health authorities to reassess the safety of certain preservatives.

“Such a review, they argue, could help improve consumer protection and inform dietary guidelines in an era of widespread consumption of ultra-processed foods.”

The strongest and most consistent associations were observed for breast cancer. Higher intakes of potassium sorbate, potassium metabisulphite, potassium nitrate and sodium erythorbate were each linked to a significantly increased risk.

The Mail Online reports Professor William Gallagher, from the School of Biomolecular and Biomedical Science, University College Dublin, said: “One cannot make causal links directly from this study.

“But it does make some interesting observations particularly in respect to an association between higher intake of non-antioxidant preservatives and higher rates of overall cancer, breast and prostate cancer.

“These higher rates of cancer are modest (e.g. 10-30 per cent increased risk) but are significant when taken at a population-based level in terms of potential impact.”