Preservatives In Processed Foods May Raise Cancer Risk, Major Study Warns

The brightly packaged foods that crowd supermarket shelves and kitchen cupboards may be carrying an unseen health cost. A large international study has found that frequent consumption of industrially processed foods and beverages containing commonly used preservatives may increase the risk of developing cancer, renewing concerns about the long-term safety of additives that have become staples of modern diets.

Published in The BMJ, the study reports that individuals with higher intake of several widely used food preservatives had a significantly increased risk of cancer compared to those who consumed little or none. These additives are routinely used to extend shelf life, improve texture and prevent spoilage in packaged snacks, soft drinks, processed meats and ready-to-eat meals.

Researchers observed that non-antioxidant preservatives showed the most consistent associations with cancer risk. Total sorbates, particularly potassium sorbate, were linked to a 14% higher risk of overall cancer and a 26% higher risk of breast cancer. Total sulfites were associated with a 12% increase in overall cancer risk.

Nitrite and nitrate compounds—commonly added to processed and cured meats—also showed troubling links. Sodium nitrite intake was associated with a 32% higher risk of prostate cancer, while potassium nitrate was linked to a 13% rise in overall cancer risk and a 22% increase in breast cancer risk.

The study, titled “Intake of food additive preservatives and incidence of cancer: results from the NutriNet-Santé prospective cohort,” further found that total acetates were associated with a 15% increase in overall cancer risk and a 25% higher risk of breast cancer. Acetic acid alone was linked to a 12% rise in overall cancer risk. Among antioxidant preservatives, only erythorbates—particularly sodium erythorbate—were associated with a higher incidence of cancer.

“This study provides new evidence that should inform the future re-evaluation of food additive safety by health authorities,” said the research team from Université Paris Cité, France. The authors stressed that while preservatives play an important role in preventing food spoilage, their long-term health effects must be carefully weighed against their benefits.

At the individual level, the researchers noted that public health advice is already unequivocal about limiting processed meat and alcohol consumption—both well-established cancer risk factors. “These remain actionable steps people can take now, even as scientific evidence on preservatives continues to evolve,” they said. The study analysed dietary and health data from 1,05,260 participants aged 15 years and above who were cancer-free at enrolment. Of the total cohort, 78.7% were women.

Researchers examined exposure to 17 food preservatives, including citric acid, lecithins, sulfites, ascorbic acid, sodium nitrite, potassium sorbate, potassium metabisulfite and potassium nitrate.

Over the follow-up period, 4,226 participants were diagnosed with cancer, including 1,208 cases of breast cancer, 508 prostate cancers, 352 colorectal cancers and 2,158 other cancer types.

While the authors cautioned that observational studies cannot establish direct causality, they noted that several preservatives may disrupt immune and inflammatory pathways—biological mechanisms that could plausibly contribute to cancer development.

Doctors in India say the findings are particularly relevant as consumption of ultra-processed foods rises rapidly across the country, cutting across age groups and socio-economic classes.

Dr. Arun Kumar Giri, Director of Surgical Oncology at Aakash Healthcare, said the study should serve as a wake-up call for families and policymakers alike. “This research suggests that frequent consumption of industrially processed foods and beverages containing common preservatives may increase cancer risk over the long term. The concern is not trivial—it is especially worrying for children, who are increasingly exposed to packaged foods from a very young age,” he said.

“This study adds to the growing body of evidence that processed foods are not harmless. As oncologists, we already see lifestyle-related cancers rising sharply in India. To protect health, we consistently advise minimal consumption of processed foods and preservatives. Fresh, home-cooked meals remain the safest and healthiest option,” Dr. Giri added.

He also called for stronger regulatory oversight of packaged foods. “There is an urgent need for stricter guidelines on processed food products. Labels should clearly mention the chemicals and preservatives used, along with evidence on their safety, particularly for children below a certain age,” he said.

Dr. Arun Kumar Gupta, paediatrician and Convenor of Nutrition Advocacy in Public Interest (NAPi), said the BMJ findings reinforce warnings already issued by international health bodies. “This study strengthens concerns highlighted by The Lancet Series on Ultra-Processed Foods and Human Health, which shows that diets dominated by ultra-processed foods pose serious long-term risks, including cancer,” he said.

“While causality cannot yet be firmly established, the consistency of associations with commonly used preservatives is significant and cannot be ignored,” Dr. Gupta said.

He emphasised that regulators must look beyond individual additives and address cumulative exposure. “The Lancet Series clearly states that assessing additives in isolation is inadequate. What matters is the combined and repeated exposure from ultra-processed diets, especially among children, adolescents and high consumers,” he said.

For India, where ultra-processed food consumption is rising rapidly and front-of-pack warning labels remain absent, the new evidence underscores the need for precautionary regulation, clearer labelling and restrictions on aggressive marketing of ultra-processed foods, particularly those targeted at children, Dr. Gupta added.