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

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.