Precarcinogens in food – Mechanism of action, formation of DNA adducts and preventive measures

Abstract

Food quality and food composition play key roles in human health. Food may contain harmful ingredients apart from the basic ingredients beneficial to our body. A harmful group of substances entering food from the environment are heavy metals and pesticides. Other toxicants, such as mycotoxins are produced during action of microorganisms contaminating food. The second group of compounds, including heterocyclic aromatic amines, nitrosamines, and acrylamide are formed in food during its processing or improper storage. Due to metabolic activation, these substances are transformed into precancerogens, i.e. electrophilic derivatives that finally form DNA adducts. DNA sites susceptible to the action of electrophilic compounds are atoms with a slight negative charge, especially the N7 position of guanine and N3 of adenine. These modifications may result in various mutations, and consequently, may lead to cancer development. This paper presents the general characteristics of main precancerogens, such as mycotoxins, polyaromatic hydrocarbons, heterocyclic aromatic amines, nitrosamines, and acrylamide present in various food products, formation of specific adducts of these substances with DNA, as well as describes biological consequences of adducts formation. Moreover, different strategies for reducing the levels of these contaminants in food material are discussed.