Pleiotropic-Acting Nutrients Require Integrative Investigational Approaches: The Example of Flavonoids

Assessment of the health effects of dietary interventions in humans poses a particular challenge to nutritional and clinical scientists. In contrast to drugs possessing a well-defined molecular mechanism of action, food-derived components act in subtle and pleiotropic ways by nature. Moreover, dietary compounds are mainly not intended to cure a disease but to prevent or beneficially affect situations when the physiology gets slightly out of homeostasis. By the example of a recent clinical pilot study, this paper illustrates an endeavor to find new strategies for the detection of health effects of flavonoids in the human vasculature. Integration of a meticulously selected cluster of relevant biomarkers eventually enabled the beneficial vascular health effects of flavonoids to be revealed. A critical appraisal of this approach for the future is provided.