A new study has found a link between consuming nitrites from drinking water and diet and the risk of developing type 2 diabetes. Nitrates and nitrates are naturally found in water and soil and are used as food preservatives to extend shelf life. The research was led by Bernard Srour and was published in the journal PLOS Medicine.
Some public health officials have suggested restricting nitrites and nitrates as food additives, however, their effect on metabolic issues and type 2 diabetes in humans is unexplored. To study the connection, researchers used data from 104,168 participants in the NutriNet-Santé prospective cohort.
The NutriNet-Santé study is an ongoing, web-based cohort study initiated in 2009. Participants aged fifteen and older enroll voluntarily and self-report medical history, sociodemographic, diet, lifestyle, and major health updates. The researchers used detailed nitrite/nitrate exposure, derived from several databases and sources, and then developed statistical models to analyze self-reported diet information with health outcomes.
The researchers found that participants in the NutriNet-Santé cohort reporting a higher intake of nitrites overall and specifically from food additives, and non-additive sources had a higher risk of developing type 2 diabetes. There was no association between nitrates and type 2 diabetes risk, and the findings did not support any potential benefits for dietary nitrites or nitrates in terms of protection against type 2 diabetes.
The study had several limitations and additional research is required to validate the results. The data were self-reported and the researchers could not confirm specific nitrite/nitrate exposure using biomarkers due to the underlying biological challenges. Additionally, people in the cohort’s demographics and behaviors may not be generalizable to the rest of the population – the cohort included a greater number of younger individuals, more often women, who exhibited healthier behaviors. Residual confounding may also have impacted the outcomes as a result of the observational design of the study.
According to the authors, “These results provide a new piece of evidence in the context of current discussions regarding the need for a reduction of nitrite additives’ use in processed meats by the food industry and could support the need for better regulation of soil contamination by fertilizers. In the meantime, several public health authorities worldwide already recommend citizens to limit their consumption of foods containing controversial additives, including sodium nitrite”.
Srour and Touvier add, “This is the first large-scale cohort study to suggest a direct association between additives-originated nitrites and type-2 diabetes risk. It also corroborates previously suggested associations between total dietary nitrites and T2D risk.”
Reference: “Dietary exposure to nitrites and nitrates in association with type 2 diabetes risk: Results from the NutriNet-Santé population-based cohort study” by Bernard Srour, Eloi Chazelas, Nathalie Druesne-Pecollo, Younes Esseddik, Fabien Szabo de Edelenyi, Cédric Agaësse, Alexandre De Sa, Rebecca Lutchia, Charlotte Debras, Laury Sellem, Inge Huybrechts, Chantal Julia, Emmanuelle Kesse-Guyot, Benjamin Allès, Pilar Galan, Serge Hercberg, Fabrice Pierre, Mélanie Deschasaux-Tanguy and Mathilde Touvier, 17 January 2023, PLOS Medicine.