Two newly released scientific studies are renewing concerns about the long-term health effects of widely used food preservatives, suggesting that regular consumption may increase the risk of developing type 2 diabetes and certain forms of cancer. The findings add to a growing body of evidence questioning the safety of additives commonly found in processed and packaged foods.
Both studies are based on data from the NutriNet-Santé cohort, one of the world’s largest ongoing nutrition research projects. Launched in France in 2009, the initiative tracks dietary habits, lifestyle factors, and health outcomes among more than 170,000 adult participants over extended periods. Researchers use detailed food records to examine how specific dietary components influence disease risk.
The first study, published earlier this week in Nature Communications, focused on the relationship between food preservatives and type 2 diabetes. Researchers analyzed data from nearly 109,000 participants who were free of diabetes at the beginning of the study period. Over time, the team monitored dietary intake and identified preservatives consumed regularly by the group.
In total, researchers cataloged 58 different preservative additives present in participants’ diets. Of those, 17 were consumed by at least 10 percent of the study population and were analyzed individually to assess their potential impact on metabolic health.
The results revealed a notable association between higher preservative intake and increased diabetes risk. Twelve specific additives were linked to a greater likelihood of developing type 2 diabetes, including potassium sorbate, potassium metabisulfite, sodium nitrite, calcium propionate, sodium acetates, sodium ascorbate, sodium erythorbate, alpha-tocopherol, rosemary extract, and several acid-based preservatives such as acetic, citric, and phosphoric acids.
After adjusting for factors such as age, body mass index, physical activity, smoking status, and overall dietary quality, researchers found that participants with the highest consumption of these preservatives faced a 47 percent higher risk of developing type 2 diabetes compared with those who consumed the lowest amounts.
A second study, published the same day in The BMJ, examined whether similar preservative exposure was linked to cancer risk. This analysis included more than 105,000 participants who were cancer-free at enrollment and followed over several years.
Researchers again focused on the same 17 preservatives that were evaluated individually in the diabetes study. During the follow-up period, 4,226 participants were diagnosed with cancer. These cases included 1,208 instances of breast cancer, 508 prostate cancers, 352 colorectal cancers, and several other cancer types.
The findings suggested that certain preservatives were associated with elevated cancer risk, particularly for breast and prostate cancers. Additives linked to increased risk included sorbates, sulfites, sodium nitrite, and acetate-based preservatives. While the studies did not establish direct causation, the statistical associations remained significant after accounting for known cancer risk factors.
Mathilde Touvier, principal investigator of the NutriNet-Santé cohort, described the research as a significant step forward in understanding the long-term health implications of food additives. In a statement released alongside the studies, she noted that this is the first time large-scale population studies have examined the direct association between preservative intake and the incidence of both cancer and type 2 diabetes.
Touvier emphasized that the findings should be interpreted cautiously and confirmed by further research. However, she also stated that the results align with previous experimental and toxicological studies suggesting potential harmful effects of certain preservatives on metabolic and cellular processes.
“These findings reinforce existing recommendations to prioritize fresh, minimally processed foods,” she said, adding that consumers should aim to limit unnecessary additives whenever possible. According to Touvier, even moderate reductions in processed food consumption could have meaningful public health benefits if the associations observed are confirmed.
Food preservatives are widely used to extend shelf life, prevent bacterial growth, and maintain color and texture in packaged foods. They are especially prevalent in processed meats, snack foods, baked goods, sauces, and ready-to-eat meals. While regulatory agencies generally consider approved preservatives safe within established limits, critics argue that cumulative exposure over decades may pose underestimated risks.
The release of the studies coincided with a broader policy discussion about diet and health. On the same day, U.S. Department of Health and Human Services Secretary Robert F. Kennedy Jr. unveiled updated dietary guidelines aimed at reducing chronic disease and improving overall nutrition among Americans.
In announcing the new guidelines, Kennedy said the focus is on simplifying dietary advice and encouraging a return to basic, whole-food eating patterns. He stressed the importance of reducing consumption of highly processed foods, which often contain multiple additives, including preservatives.
“American households must prioritize whole, nutrient-dense foods,” Kennedy said in a statement. “Protein, dairy, vegetables, fruits, healthy fats, and whole grains should form the foundation of the diet, while highly processed foods should be dramatically reduced.”
Public health experts note that the U.S. diet, like those in many industrialized countries, relies heavily on ultra-processed foods, which account for a significant share of daily calorie intake. These foods are often energy-dense but nutritionally poor and may contain combinations of preservatives, emulsifiers, and artificial sweeteners.
While the NutriNet-Santé studies were conducted in France, researchers say the findings are relevant globally due to the widespread use of similar additives across food systems. They also highlight the need for further investigation into how multiple additives may interact within the body over long periods.
For consumers, the research adds to growing calls for transparency, clearer labeling, and increased awareness of what goes into everyday foods. Nutrition experts recommend reading ingredient lists, cooking more meals at home, and favoring fresh or minimally processed products as practical steps to reduce preservative intake.
As researchers continue to explore the long-term effects of food additives, the latest findings underscore a broader shift in nutrition science—one that increasingly focuses not only on nutrients like fat, sugar, and salt, but also on the industrial processes and chemical compounds that shape modern diets.
James Jenkins is a celebrated Pulitzer Prize-winning author whose work has reshaped the way readers think about social justice and human rights in America. Raised in Atlanta, Georgia, James grew up in a community that instilled in him both resilience and a strong sense of responsibility toward others. After studying political science and creative writing at Howard University, he worked as a journalist covering civil rights issues before dedicating himself fully to fiction. His novels are known for their sharp, empathetic portraits of marginalized communities and for weaving personal stories with broader political realities. Jenkins’s breakout novel, Shadows of Freedom, won national acclaim for its unflinching look at systemic inequality, while his more recent works explore themes of identity, resilience, and the fight for dignity in the face of oppression. Beyond his novels, James is an active public speaker, lecturing at universities and participating in nonprofit initiatives that support literacy and community empowerment. He believes that storytelling is a way to preserve history and inspire change. When not writing, James enjoys jazz music, mentoring young writers, and traveling with his family to explore cultures and stories around the world.
