A comprehensive investigation involving over 100,000 French adults has revealed a significant association between higher consumption of common food preservatives and an increased likelihood of developing type 2 diabetes. This landmark research, spearheaded by a collaborative team from Inserm, INRAE, Sorbonne Paris Nord University, Paris Cité University, and Cnam, as part of the Nutritional Epidemiology Research Team (CRESS-EREN), offers crucial insights into the potential health implications of widely used food additives. The findings, meticulously detailed in the esteemed scientific journal Nature Communications, represent a pivotal moment in understanding the intricate relationship between our diets and metabolic health.
Preservatives, a ubiquitous class of food additives, play a critical role in modern food production by significantly extending the shelf life of processed goods and beverages, thereby reducing spoilage and waste. Their pervasive presence in the global food system is underscored by recent data; in 2024, the Open Food Facts World database cataloged approximately three and a half million food and beverage products, with a staggering 700,000 of these containing at least one preservative. This widespread integration necessitates a deeper examination of their impact on human health.
The Inserm researchers meticulously categorized the preservative additives under scrutiny into two principal classifications. The first group encompasses non-antioxidant preservatives, which function by inhibiting the growth of microorganisms or retarding chemical reactions that lead to food spoilage. The second category comprises antioxidant additives, designed to preserve food by mitigating or controlling its exposure to oxygen, a primary driver of oxidative degradation. On product ingredient lists, these additives are typically identified by European codes, with preservatives in the strict sense falling within the E200 to E299 range, and antioxidant additives designated between E300 and E399.
The scientific rationale for investigating preservatives stems from prior experimental studies that have raised concerns about their potential to induce cellular or DNA damage and to disrupt normal metabolic pathways. However, robust, direct evidence linking preservative intake to type 2 diabetes incidence in large human populations has remained elusive until the completion of this extensive study.
To comprehensively address this potential health concern, a research consortium, under the leadership of Mathilde Touvier, an Inserm Research Director, embarked on a long-term examination of dietary preservative exposure and its correlation with the development of type 2 diabetes. This ambitious undertaking leveraged the rich and detailed health and dietary data collected from participants within the ongoing NutriNet-Santé cohort study.
The study meticulously tracked the health and dietary habits of over 100,000 French adults for a substantial period, spanning from 2009 to 2023. Throughout this extensive timeframe, participants consistently provided comprehensive information regarding their medical histories, socio-demographic backgrounds, physical activity levels, lifestyle choices, and overall health status. Crucially, they also submitted meticulously detailed dietary records, capturing multiple 24-hour periods of consumption. These records meticulously listed not only the types of food consumed but also the specific brands of industrially produced food products they incorporated into their diets.
The research team then ingeniously cross-referenced this detailed participant data with a suite of authoritative databases, including Open Food Facts, Oqali, and EFSA (European Food Safety Authority). This vital step allowed for the precise measurement of additive content in the consumed foods and beverages, enabling the researchers to accurately estimate each participant’s cumulative, long-term exposure to various preservatives.
In their detailed analysis of dietary records, the researchers identified a comprehensive spectrum of 58 distinct preservative-related additives. This broad inventory included 33 preservatives classified in the strict sense and 27 identified as antioxidant additives. To ensure statistical robustness and focus on commonly consumed substances, 17 of these preservatives were selected for individual analysis, based on their consumption by at least 10% of the study participants. The analytical framework was designed to rigorously control for a multitude of confounding factors that could independently influence diabetes risk. These included established variables such as age, sex, educational attainment, smoking status, alcohol consumption, and critical dietary components like overall caloric intake, sugar, salt, saturated fat, and fiber content.
Over the extensive duration of the study, a total of 1,131 new cases of type 2 diabetes were diagnosed among the 108,723 participating adults. The statistical analysis revealed a clear and compelling trend: individuals who reported the highest levels of preservative consumption exhibited a markedly elevated risk of developing type 2 diabetes when contrasted with those who consumed the lowest amounts. Specifically, overall preservative consumption was associated with a 47% higher risk. This heightened risk was further broken down by preservative type, with non-antioxidant preservatives showing a 49% increase in risk, and antioxidant additives linked to a 40% higher risk.
Delving deeper into the data, the study pinpointed specific preservatives whose higher intake was significantly associated with an increased risk of type 2 diabetes. Among the 17 preservatives analyzed individually, the consumption of 12 was found to be correlated with a greater incidence of the disease. These included widely utilized non-antioxidant preservatives such as potassium sorbate (E202), potassium metabisulphite (E224), sodium nitrite (E250), acetic acid (E260), sodium acetates (E262), and calcium propionate (E282). The list also included several antioxidant additives, namely sodium ascorbate (E301), alpha-tocopherol (E307), sodium erythorbate (E316), citric acid (E330), phosphoric acid (E338), and rosemary extracts (E392).
"This study represents a world-first investigation into the potential links between preservative additives and the incidence of type 2 diabetes," stated Mathilde Touvier, the Inserm research director who coordinated this significant research effort. "While these findings warrant further validation, they align remarkably well with existing experimental data that suggest detrimental effects from several of these compounds," she added.
Anaïs Hasenbühler, a doctoral student at EREN who played a key role in conducting these analyses, emphasized the broader implications of the findings. "More generally, these new data contribute to a growing body of evidence supporting the need for a reassessment of the regulations governing the widespread use of food additives by the food industry, with the ultimate goal of enhancing consumer protection," she commented.
Concluding, Mathilde Touvier reiterated the practical recommendations derived from this research. "This work once again validates the recommendations promoted by the National Nutrition and Health Programme, which advise consumers to prioritize fresh, minimally processed foods and to limit the intake of unnecessary additives whenever possible," she affirmed. The foundational research for this study received substantial funding from prestigious institutions including the European Research Council (ERC ADDITIVES), the National Cancer Institute, and the French Ministry of Health, underscoring its scientific and public health importance.
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