Cancer is one of the leading causes of deaths worldwide. The agents capable of causing damage to genetic material are known as genotoxins and, according to their mode of action, are classified into mutagens, carcinogens or teratogens. Genotoxins are involved in the pathogenesis of several chronic degenerative diseases including hepatic, neurodegenerative and cardiovascular disorders, diabetes, arthritis, cancer, chronic inflammation and ageing. In recent decades, researchers have found novel bioactive phytocompounds able to counteract the effects of physical and chemical mutagens. Several studies have shown potential antigenotoxicity in a variety of fruits. In this review (Part 1), we present an overview of research conducted on some fruits (grapefruit, cranberries, pomegranate, guava, pineapple, and mango) which are frequentl consumed by humans, as well as the analysis of some phytochemicals extracted from fruits and yeasts which have demonstrated antigenotoxic capacity in various tests, including the Ames assay, sister chromatid exchange, chromosomal aberrations, micronucleus and comet assay.