Nitrates, Nitrites and Nitrosamines from Processed Meat Intake and ColorectalCancer Risk

Marie Cantwell,Chris Elliott

doi:10.4172/2472-1921.100062

Abstract

The International Agency for Research on Cancer reported that eating processed meat can increase a person’s risk for colorectal cancer and classified processed meat as carcinogenic to humans. Nitrate and nitrite are used as additives to improve food quality and protect against microbial contamination and are sources of N-nitroso compounds (NOCs) which are known carcinogens. This review outlines the association between processed meat intake and colorectal cancer risk and discusses the use of nitrates and nitrites in processed meat as well as healthier alternatives. A wide range of factors affect the formation of NOCs including the amount of nitrite added, meat quality, fat content, processing, maturation and handling at home. Factors related to processing include additives, precursors (added via wood smoke, spices or other ingredients), heat applied during drying or smoking, storage/maturation conditions and packaging. NOC formation can be inhibited by the addition of ascorbic acid and α-tocopherol ingredients which are often added to processed meats. Studies have shown that plant polyphenols and alpha-tocopherol significantly decreased pH, lipid oxidation and residual nitrite content of processed meat. Plant polyphenols, especially green tea polyphenols can be used as alternatives to nitrates and nitrites to process meat improving the quality, shelf life and safety of processed meat products. These innovative meat products could potentially contribute to a reduction in cancer risk by means of nitrite reduction and phytochemical addition and should be explored further.

Highlights

Processed meat and colorectal cancerThe International Agency for Research on Cancer (IARC) recently reported that eating processed meat can increase a person’s risk for colorectal cancer [1] and classified processed meat as carcinogenic to humans (Group1) based on sufficient evidence from epidemiological studies
Findings from the European Prospective Investigation into Cancer (EPIC), a large prospective study which investigated the association between dietary nitroso compounds (NOCs) and cancer risk, showed that gastrointestinal cancer incidence and with risk of rectal cancer was associated with dietary NDMA (HR: 1.13; 95% CI: 1.00, 1.28; HR: 1.46; 95% CI: 1.16, 1.84 per 1-SD increase respectively) but not with endogenous NOCs or nitrite [10]
NOC formation can be inhibited by the addition of ascorbic acid and α-tocopherol [14,15] ingredients which are often added to processed meats

Summary

Introduction

Processed meat and colorectal cancerThe International Agency for Research on Cancer (IARC) recently reported that eating processed meat can increase a person’s risk for colorectal cancer [1] and classified processed meat as carcinogenic to humans (Group1) based on sufficient evidence from epidemiological studies. One of the proposed mechanisms whereby processed meat can increase colorectal cancer is the formation of N-nitrosamines (NOC), which result from the reaction between a nitrosating agent, originating from nitrate (NO3)/nitrite (NO2) or smoke and a secondary amine, derived from protein [3]. The richest food sources of nitrosamines are bacon, luncheon meats, hot dogs and sausages with added nitrates/nitrites such as chorizo and salami.Nitrite is an active ingredient used as a food additive to extend shelf life, to provide protection against the bacteria Clostridium botulinum and to give processed meat its typical pink colour.

Results

Conclusion