Carotenoids and Cancer

Abstract

A. Introduction Cancer is a major cause of morbidity and mortality around the world, although patterns of cancer, like dietary patterns, are highly variable across regions and countries with different degrees of economic development [1]. Observed associations between dietary patterns and cancer mortality and morbidity have led to hypotheses about cause and effect relationships, which have subsequently been examined more specifically in laboratory studies of biological activities of dietary constituents, case-control and cohort studies within populations, and clinical trials. Food provides nutrients and numerous other bioactive compounds, many of which have been linked specifically to cellular and molecular events and activities that have been identified in the development and progression of cancer [2,3]. Carotenoids are among the bioactive substances that potentially affect risk and progression of cancer, and that have been the focus of numerous investigations. As summarized in comprehensive reviews [4,5], accumulated data on diet and cancer over the past several decades suggest that approximately 30-40% of cancer cases are potentially preventable via food choices and the modification of nutritional factors. However, disentangling the effects of various foods, specific dietary constituents, and related lifestyle factors and characteristics (e.g. physical activity, obesity) that influence risk and progression of cancer has proved to be very challenging. This challenge is particularly evident when the relationship between carotenoids and cancer is examined, due to the distribution of these compounds in the food supply and the clustering of health-related behaviours. The aim in this Chapter is to evaluate the relationship between carotenoids and cancer from data obtained by different experimental approaches. The design, application and interpretation of epidemiology studies are described