Research has proved a relationship between functional components of food, health and well-being. Thus, functional components of food can be effectively applied in the treatment and prevention of diseases. They act simultaneously at different or identical target sites with the potential to impart physiological benefits and promotion of wellbeing including reducing the risk of cancer, cardiovascular disease, osteoporosis, inflammation, type II diabetes, and other chronic degenerative diseases, lowering of blood cholesterol, neutralization of reactive oxygen species and charged radicals, anticarcinogenic effect, low-glycaemic response, etc. Previously, it was thought that functional ingredients such as non-starchy carbohydrates including soluble and insoluble dietary fibres, fucoidan; antioxidants including polyphenols, carotenoids, tocopherols, tocotrienols, phytosterols, isoflavones, organosulphur compounds; plant sterols and soy phytoestrogens occur only in plant foods (whole grains, fruits, and vegetables) as phytochemicals. However, probiotics, prebiotics, conjugated linolenic acid, long-chain omega-3, -6 and -9-polyunsaturated fatty acids, and bioactive peptides have proved that functional components are equally available in animal products such as milk, fermented milk products and cold-water fish. The way a food is processed affects its functional components. Many processing techniques have been found to lower the concentration of functional components in food. Conversely, other techniques were found to increase them. Hence, in a time when the role of a healthy diet in preventing non-communicable diseases is well accepted, the borderline between food and medicine is becoming very thin.
Keywords: Biomolecules; Foods; Functional; Medicine; Physiological; Phytochemicals.