Nitrites and nitrates are naturally occurring compounds found in water and soil. They are also commonly added to processed meats as food additives to extend their shelf life and prevent bacterial growth. While some studies have suggested that nitrites and nitrates may benefit T2D, epidemiological and clinical data on this topic still need to be included.
According to a study published in PLOS Medicine, researchers from the French NutriNet-Santé cohort study conducted a large population-based prospective cohort study to address this knowledge gap. The study included 104,168 adults (79.1% female, mean age 42.7 [14.5]) and evaluated self-reported exposure to nitrites and nitrates using repeated 24-hour dietary records. The study also accounted for commercial names/brands of industrial products.
After a median follow-up duration of 7.3 years, the study found that both total nitrites and foods and water-originated nitrites were positively associated with a higher T2D risk. Participants with higher exposure to additives-originated nitrites had a higher T2D risk than those not exposed to these compounds. However, there was no evidence of an association between nitrates and T2D risk.
The study involved 104,168 adults and used appropriate statistical models to investigate the association between dietary exposure to nitrites/nitrates and T2D risk. During a median follow-up duration of 7.3 years, 969 incident T2D cases were ascertained. The results showed that total dietary nitrites and foods and water-originated nitrites were both positively associated with a higher T2D risk, with HRtertile 3 vs. one at 1.27 (95% CI 1.04 to 1.54) and Ptrend at 0.009 and 1.26 (95% CI 1.03 to 1.54) and Ptrend at 0.02, respectively.
This is also the first study to explicitly correlate exposure to nitrites from additives, namely sodium nitrite (e250), with the development of type 2 diabetes. The hazard ratio (HR) for people who ate more processed meats was 1.53 (95% CI 1.24 to 1.88), and for people who did not eat processed meats was 1.54 (95% CI 1.26 to 1.90), both of which were significant at the 0.001 level, indicating that people who ate more processed meats were more likely to develop type 2 diabetes than those who did not.
The findings imply a direct association between nitrites derived from additives and T2D risk, which is consistent with prior research linking total dietary nitrites to an increased risk of T2D. Nevertheless, because this was an observational study, there are limits in precisely assessing exposures and eliminating the effects of selection bias and residual confounding.
The study’s results could provide new evidence in the context of current discussions regarding reducing additives-originated nitrites in the food industry and support the need for better regulation of soil contamination. Although further research is needed to confirm the findings of this study, the results highlight the importance of considering the potential risks associated with dietary exposure to nitrites and nitrates, particularly those originating from food additives, and their impact on public health.
This study’s findings could have implications for food manufacturers and regulators, as they suggest that additives-originated nitrites may increase the risk of developing T2D. Therefore, reducing the use of additives-originated nitrites in food production and developing better regulations to control soil contamination could be necessary to promote public health and reduce the incidence of T2D.