Mediterranean food and health: building human evidence.

Adherence to a Mediterranean style diet affords protection from degenerative diseases such as cardiovascular disorders and cancer. Identification of the active constituents of the Mediterranean diet is crucial to the formulation of appropriate dietary guidelines. Also, research on the pharmacological properties of the "minor components" of this diet, eg vitamins and polyphenols, is very active and might lead to the formulation of functional foods and nutraceuticals. Even though in vitro data are plentiful, human studies are difficult to perform due to ethical and practical reasons. Yet, intervention trials represent the best approach to validate claims of healthful activities. This article reviews human evidence of the biological properties of olive oil and tomato constituents and illustrates a research approach by which the bioactive elements of a wild plant (Cynara cardunculus) are first studied in vitro to build biochemical evidence, then in vivo to obtain proof of their vasomodularoty activity.