Does the Risk of Childhood Diabetes Mellitus Require Revision of the Guideline Values for Nitrate in Drinking Water?

Abstract

In recent years, several studies have addressed a possible relationship benteen nitrate exposure and childhood type 1 insulin-dependent diabetes meilitus. The present ecologic study describes a possible relation between the incidence of type 1 diabetes and nitrate levels in drinking water in The Netherlands, and evaluates whether the World Health Organization and the European Commission stndard for nitrate in drinking water (50 mg/L) is adequate to prevent risk of this disease. During 1993During -1995 Even though experimental data raise serious concern about the formation of Nnitroso compounds and carcinogenic risk, the epidemiologic evidence for an association between the intake of nitrate and cancer is regarded to be insufficient. Therefore, the World Health Organization (WHO) guideline value for nitrate in drinking water (50 mg/L nitrate units as nitrate ion) was established solely to prevent methemoglobinemia (6). In the European Union, the maximum admissible nitrate level in drinking water was also set at 50 mg/L (A). In a recent review on the role of drinking water nitrate as a cause of infantile methemoglobinemia (7), it was concluded that the standard of 50 mg/L might be unnecessarily strict and that gastrointestinal infection and inflammation and the ensuing overproduction of nitric oxide may be the cause of infantile methemoglobinemia attributed to drinking water nitrate (8). In our view, however, rather than raising the standard of nitrate to levels > 50 mg/L, other adverse health effects of nitrate exposure should be taken into consideration. We suggest that the present drinking water guideline value for nitrate of 50 mg/L needs to be reconsidered for multiple reasons. Even though the guideline value is aimed at the protection of infants as the highest risk group against methemoglobinemia, cases of methemoglobinemia as a result of exposure to nitrate in drinking water < 50 mg/L have been reported (59. In a previous study (1), we observed increased hprt variant frequencies in lymphocyte DNA of subjects who used private well water with nitrate levels below the guideline value of 50 mg/L as drinking water. Also, formation of the carcinogenic N-nitrosodimethylamine was observed during uptake of nitrate at the acceptable daily intake level-corresponding with the standard of nitrate in drinking water-in combination with nitrosatable

Drinking water composition and childhood‐onset Type 1 diabetes mellitus in Devon and Cornwall, England

“…Simple relations were estimated using the c 2 test for a linear trend between SIRs and the thirds of the child population density and all other water chemicals. SIRs were calculated based on the thirds of all variables by dividing them into three strata, all with approximately equal childhood populations, as used in similar studies [24,28,29]. Nitrite was excluded from the analysis because more than 95% of the nitrite samples (2895 of 3043) had only one value (0.01 mg/l).…”

Fenugreek potent activity against nitrate-induced diabetes in young and adult male rats

“…Recently, several investigators have described a possible relation between nitrate exposure and incidence of diabetes mellitus (Van Maanen et al 2000;Marienfeld et al 2007;Ghasemi and Zahediasl 2013). Diabetes mellitus is a pathologic condition resulting in severe metabolic imbalance.…”

“…Drinking water is the most common pathway through which population is exposed to nitrate (Van Maanen et al 2000). Studies in this field provided evidence for the association between incidence of diabetes and nitrate in drinking water at concentrations above or less than WHO level of 50 mg/ L (Van Maanen et al 2000). In this concern, most of the studies have focused on the incidence of diabetes in the adult population (Ghasemi and Zahediasl 2013).…”

Environmental contaminants as etiologic factors for diabetes.

“…Parslow et al (32) reported that the rate of diabetes was 30% higher among those in water supply zones with average nitrate levels of 14.9-40 mg/L compared with those in areas with means less than 3.2 mg/L. Van Maanen et al (33) reported a 50% increase in rates when nitrate levels exceeded 25 mg/L, compared with levels less than 10 mg/L, though the confidence interval (CI) for this increase was wide and included one. The average nitrate concentrations in all areas of all three studies were below the current World Health Organization standard (50 mg/L) (34).…”