Study Links Food Preservatives to Higher Diabetes Risk

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A higher intake of several common food preservatives was linked to an increased risk of Type 2 diabetes, according to research published in Nature Communications.

Many packaged and processed foods contain preservatives designed to extend shelf life, prevent spoilage or maintain color and flavor. While laboratory and animal studies have suggested that some of these additives may negatively affect metabolism, there has been limited real-world data linking preservative intake to chronic disease risk.

A new large, long-term French study helps fill that gap by examining whether exposure to commonly used food preservatives is associated with the development of Type 2 diabetes.

“This is the first study in the world on the links between preservative additives and the incidence of Type 2 diabetes,” explained study coordinator Mathilde Touvier, Ph.D., M.P.H., Inserm research director.

Investigators analyzed data from the NutriNet-Santé study, a large ongoing prospective cohort in France that followed more than 108,000 adults over up to 14 years. Participants regularly completed detailed 24-hour dietary records, allowing researchers to estimate preservative intake using multiple food composition databases and laboratory testing of food products. The study tracked new cases of Type 2 diabetes over time, identifying 1,131 cases during the follow-up period.

The researchers examined exposure to 58 different food preservatives, focusing more closely on 17 additives that were consumed by at least 10% of participants. After adjusting for many factors that can influence diabetes risk, such as age, sex, lifestyle, body weight and overall diet quality, they found that 13 commonly used preservatives were linked to a higher risk of developing Type 2 diabetes.

These included preservatives often found in processed meats, baked goods, sauces, snacks and beverages, such as potassium sorbate, sodium nitrite, calcium propionate, sodium acetates and phosphoric acid, as well as additives used for antioxidant or color-preserving effects like sodium ascorbate, alpha-tocopherol, sodium erythorbate and rosemary extract.

“Although the results need to be confirmed, they are consistent with experimental data suggesting the harmful effects of several of these compounds,” noted Touvier.

Importantly, the study did not prove that preservatives directly cause diabetes, but it did identify consistent associations between higher cumulative exposure to certain additives and increased diabetes risk. The findings suggest that long-term, repeated exposure, even at levels considered acceptable, may contribute to metabolic health problems over time.

Investigators mentioned some limitations of the study, including its observational nature, meaning it looked at patterns rather than cause and effect. The team tried to reduce bias by carefully adjusting for diet quality, calories and other lifestyle factors, but some uncertainty is always possible. The participants were generally healthier and more educated than the broader population, which means the results may not apply to everyone, although their overall diets were similar to national averages.

While no study is perfect, investigators used detailed and repeated diet tracking methods, making their estimates of preservative intake among the most accurate available.

They concluded that these results support current public health recommendations to favor fresh, minimally processed foods and highlight the need to re-evaluate the safety of widely used food preservatives, particularly as consumption of ultraprocessed foods continues to rise.

“These new data add to others in favor of a reassessment of the regulations governing the general use of food additives by the food industry in order to improve consumer protection,” said study investigator Anaïs Hasenböhler, a doctoral student at EREN.