Nitrate and Nitrite Intake and the Risk for Type 1 Diabetes in Finnish Children

The intakes of nitrate and nitrite of children and their parents from food and drinking water were estimated in a Finnish nation-wide case-control study on the epidemiology of Type 1 diabetes. The study population consisted of 684 case and 595 control children; 548 case-control pairs of fathers; and 620 case-control pairs of mothers. The consumption frequencies of foods which are important sources of nitrate and nitrite were assessed by structured questionnaire. Nitrate and nitrite concentration data were collected from Finnish water works. Diabetic children's and their mothers' daily dietary intake of nitrite was greater compared with that of control children and mothers (for case and control children 0.9 mg vs 0.8 mg, for case and control mothers 0.9 mg vs 0.8 mg, p<0.001). Case mothers compared with control mothers received less (p<0.05) nitrate from their diet. No differences were observed in the intake of nitrate or nitrite from drinking water. Dietary nitrite intake of children (odds ratios and 95% confidence intervals for the second, third, and fourth quartile 1.16, 0.82–1.65; 1.49, 1.06–2.10; 2.32, 1.67–3.24, respectively) and mothers (odds ratios and 95% confidence intervals for the second, third, and fourth quartile 1.15, 0.76–1.74; 1.29, 0.87–1.91; 1.98, 1.35–2.90, respectively) was positively associated with the risk for Type 1 diabetes independently from length of mother's education, child's or mother's age, place of residence or mother's smoking status. The present study gives supporting evidence that dietary nitrites, from which N-nitroso compounds can be formed in foods and in the human body, are associated with the development of Type 1 diabetes in man.