# Dietary exposure to N-nitrosamines and their precursors: an age-stratified assessment

## TL;DR

This study assesses dietary exposure to N-nitrosamines in children and adults in Spain, finding that processed meats are a major source and that early childhood is a critical period for reducing cancer risk.

## Contribution

The study provides age-specific dietary exposure data to N-nitrosamines and identifies critical windows for public health intervention.

## Key findings

- Processed meats are the main source of N-nitrosodimethylamine (NDMA) intake in children.
- 12-19% of adults exceed the acceptable daily intake of nitrites.
- MOEs below 10,000 for N-NAs were observed from 12 months to 95 years.

## Abstract

Dietary exposure to N-nitrosamines (N-NAs) may pose health concerns across all age groups, particularly in children and the elderly, due to their association with increased cancer risk. This study risk-assessed age-specific dietary intake of N-NAs and main dietary sources. N-NAs consumption was estimated from 671 questionnaires (validated Food Frequency Questionnaires) obtained from 116 children (followed-up from 6 months to 4 years) and 182 adults (aged 19 to 95 years) from northern Spain (Asturias). The content of nitrates, nitrites and N-NAs was calculated per 100 g of food for 348 items primarily using EFSA and EPIC data. Intakes were standardized by body weight and dietary sources were analysed using the FoodSources Shiny-app. The highest mean N-NAs intake, mainly of N-Nitrosodimethylamine (NDMA), was observed at 48 months and was derived from processed meats. Among adults, nitrite intake was primarily attributable to animal sources and 12 to 19% of individuals exceeded the acceptable daily intake (ADI). In children, the lowest margin of exposure (MOE) for N-NAs was found at 48 months, and MOEs below 10,000 were observed from 12 months to 95 years. Early childhood appears to be a critical window for reducing exposure to carcinogens, supporting the development of targeted public-health policies.

The online version contains supplementary material available at 10.1038/s41598-025-34144-7.