Exploring Individual Factors Affecting Endothelial Function Response Variability in Aging: Implications for Precision Nutrition.

Aging is a major non-modifiable risk factor for cardiovascular disease (CVD), in part due to its detrimental effects on vascular endothelial function. Dietary interventions, including those rich in plant-based components or following dietary patterns such as the Mediterranean Diet, have been shown to improve endothelial function in older adults, assessed via brachial artery flow-mediated dilation (FMD). However, it is well recognized that FMD responses to dietary interventions often show considerable variability among individuals. This variability presents a major challenge to translating findings into effective, population-level guidance highlighting the need for more tailored approaches for CVD risk prevention. Thus, to advance these precision nutrition approaches, research must move beyond the overall group mean effects and begin to investigate the factors driving this variability. This narrative review summarizes current evidence on nutritional interventions that improve endothelial function with aging, highlights potential contributors to individual response variability, and outlines future research directions to reduce this variability to enhance clinical relevance and advance precision nutrition for the aging population.