Figure 1. Unique challenges in selecting outcome measures which are responsive to resveratrol treatment in healthy individuals. (A) When there is a continuum for an outcome measure such that values above or below a reference range are pathological (e.g., fasting glucose or blood pressure), it is advantageous for resveratrol treatment to produce an effect in the pathological population. However, in healthy individuals, homeostatic control mechanisms should prevent these values from dropping below a certain healthy threshold to create pathology. As such, these types of outcome measures are likely to exhibit a limited range of response to resveratrol.
(B) When plasma biomarkers are above normal reference range, there is often known benefit in reducing them. However, in the healthy population, most biomarkers associated with pathology (e.g., inflammatory cytokines) are found at very low concentrations. The physiological benefits of further reducing these biomarkers remains unknown, and the limited possible range for response creates statistical limitations.