Food and cancer.

Food is an important factor in determining cancer incidence in many countries and regions. Food components relevant to cancer development can be divided into macro- and microcomponents. The former tends to act indirectly. The latter usually has a clearly defined action, for example as genotoxic agents. Food can have both positive (carcinogenic) and negative (preventive) effects. Total calory intake appears to have a strong positive influence on cancer incidence. Food typical of advanced nations including fat-rich food is associated with increases in breast, colon and prostate cancers. Vegetables rich in antioxidants and fibers tend to reduce cancer incidence. Carcinogenic plant alkaloids, myctoxins and other food contaminants frequently enter our bodies. Heat-cooking generates genotoxicants, including aromatic hydrocarbons (via combustion) and heterocyclic amines (HCAs) through reactions involving creatin(in)e, sugar and amino acids in meat. HCAs are relatively newcomers as food genotoxicants and can produce breast, colon and prostate cancers in rodents. Some epidemiological investigations positively correlate HCA intake and cancer incidence. HCAs can produce other toxicological effects including salivary gland atrophy and myocardial degeneration. Improved food, better life styles and developments in the functional food industry are all crucila to cancer prevention.