ARS | Publication request: N-Nitroso compounds: Assessing agreement between food frequency questionnaires and 7-day food records

Submitted to: Journal Of The American Dietetic Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 30, 2008
Publication Date: March 2, 2009
Citation: Stuff, J., Goh, E.T., Barrera, S.L., Bondy, M.L., Forman, M.R. 2009. N-Nitroso compounds: Assessing agreement between food frequency questionnaires and 7-day food records. Journal Of The American Dietetic Association. 109:1179-1183.

Interpretive Summary: Low levels of N-nitroso compounds can be found in air, water, and food products treated with nitrite. N-nitroso compounds are chemical compounds that have the potential to cause certain forms of cancer. It is important to identify which foods contain these compounds and the levels present, in order to avoid or at least curtail eating these food sources and reduce the risk of cancer. Examples of foods known to contain these compounds are certain processed meats and other food sources. A database of values of N-Nitroso compounds was developed according to food sources, and it was linked to an existing food frequency questionnaire (FFQ). In large health surveys, researchers use FFQ’s to measure food intakes of individuals. This research evaluated the accuracy of the FFQ instrument modified to estimate N-nitroso compounds and found that FFQ with N-nitroso values is a useful tool for assessing N-nitroso intakes. As a result, this FFQ can be used in future research involving N-nitroso studies.

Technical Abstract: N-nitroso compounds are recognized as important dietary carcinogens. Accurate assessment of N-nitroso intake is fundamental to advancing research regarding its role with cancer. Previous studies have not used a quantitative database to estimate the intake of these compounds in a US population. To address this gap, a database of N-nitroso values was developed in conjunction with an existing food frequency questionnaire (FFQ). In this article, we report on the relative validity of the FFQ instrument modified to estimate intake of N-nitroso compounds. Intake estimates of 23 N-nitroso compounds from the FFQ were compared with those from 7-day food records in a cross-sectional study conducted from January 2005 through June 2006. A sample of 98 healthy adult subjects (aged 50.42+/-12.84 years) completed an FFQ and then recorded foods and beverages consumed on 7-day food records. Crude and energy-adjusted N-nitroso compounds intakes were significantly higher in the FFQ than the 7-day food records (P<0.001). Spearman correlations for crude and energy-adjusted N-nitroso intakes ranged from 0.004 to 0.48. By tertiles of N-nitiroso compounds, there was moderate agreement (kappa>0.30) for 5 compounds. Higher estimates of N-nitroso compounds by FFQ was explained by a greater proportion of subjects who reported eating foods high in N-nitroso compounds on FFQ than reported on 7-day food records. The modified FFQ with N-nitroso values is a useful tool for assessing N-nitroso intakes relative to a group, and captures all food items with N-nitroso compounds, including those foods with high concentrations and eaten sporadically.