Research
Maternal characteristics associated with the dietary intake of nitrates, nitrites, and nitrosamines in women of child-bearing age: a cross-sectional study
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* Corresponding author: Jean D Brender jdbrender@srph.tamhsc.edu
1 Department of Epidemiology and Biostatistics, School of Rural Public Health, Texas A&M Health Science Center, College Station, TX, 77843-1266, USA
2 Department of Social and Behavioral Health, School of Rural Public Health, Texas A&M Health Science Center, College Station, TX, 77843-1266, USA
3 Department of Environmental and Occupational Health, School of Rural Public Health, Texas A&M Health Science Center, College Station, TX, 77843-1266, USA
4 Department of Epidemiology, 200 Hawkins Dr, University of Iowa, Iowa City, IA, 52242, USA
5 Birth Defects Epidemiology and Surveillance Branch, Texas Department of State Health Services, PO Box 149347, MC 1964, Austin, TX, 78714-9347, USA
6 Environmental Epidemiology and Disease Registries Section, Texas Department of State Health Services, 1100 W. 49th St, Austin, TX, 78756, USA
Environmental Health 2010, 9:10 doi:10.1186/1476-069X-9-10
Published: 19 February 2010Abstract
Background
Multiple N-nitroso compounds have been observed in animal studies to be both mutagenic and teratogenic. Human exposure to N-nitroso compounds and their precursors, nitrates and nitrites, can occur through exogenous sources, such as diet, drinking water, occupation, or environmental exposures, and through endogenous exposures resulting from the formation of N-nitroso compounds in the body. Very little information is available on intake of nitrates, nitrites, and nitrosamines and factors related to increased consumption of these compounds.
Methods
Using survey and dietary intake information from control women (with deliveries of live births without major congenital malformations during 1997-2004) who participated in the National Birth Defects Prevention Study (NBDPS), we examined the relation between various maternal characteristics and intake of nitrates, nitrites, and nitrosamines from dietary sources. Estimated intake of these compounds was obtained from the Willet Food Frequency Questionnaire as adapted for the NBDPS. Multinomial logistic regression models were used to estimate odds ratios and 95% confidence intervals for the consumption of these compounds by self-reported race/ethnicity and other maternal characteristics.
Results
Median intake per day for nitrates, nitrites, total nitrites (nitrites + 5% nitrates), and nitrosamines was estimated at 40.48 mg, 1.53 mg, 3.69 mg, and 0.472 μg respectively. With the lowest quartile of intake as the referent category and controlling for daily caloric intake, factors predicting intake of these compounds included maternal race/ethnicity, education, body mass index, household income, area of residence, folate intake, and percent of daily calories from dietary fat. Non-Hispanic White participants were less likely to consume nitrates, nitrites, and total nitrites per day, but more likely to consume dietary nitrosamines than other participants that participated in the NBDPS. Primary food sources of these compounds also varied by maternal race/ethnicity.
Conclusions
Results of this study indicate that intake of nitrates, nitrites, and nitrosamines vary considerably by race/ethnicity, education, body mass index, and other characteristics. Further research is needed regarding how consumption of foods high in nitrosamines and N-nitroso precursors might relate to risk of adverse pregnancy outcomes and chronic diseases.