Fasting Diets and Vascular Health: Scoping Review with ☸SAIMSARA

This paper aims to synthesize current evidence on the effects of fasting diets on vascular health, drawing from both human clinical trials and animal experimental studies, to identify consistent findings, explore underlying mechanisms, and highlight areas for future research. The review utilises 32 original studies with 7427 total participants (topic deduplicated ΣN). Across the mapped evidence, fasting interventions most consistently aligned with improvements in macrovascular function, including enhanced arterial compliance and reduced arterial stiffness, alongside repeated signals of lower vascular oxidative stress and inflammation in experimental models. A notable counter-signal is that microvascular endothelial health may not uniformly improve: in type 2 diabetes, one randomized trial reported worsening of a microvascular parameter despite improvements in cardiometabolic markers. Mechanistic findings support a plausible vascular-protective pathway through fasting-associated metabolic switching, including β-hydroxybutyrate–linked, autophagy-dependent vasodilation, and immune/microbiome-related modulation of vascular risk phenotypes. Clinically, these patterns suggest fasting regimens may be a useful adjunct for cardiometabolic risk reduction and macrovascular health in selected patients, but warrant caution and monitoring when microvascular disease is present or when diabetes-related microvascular vulnerability is a concern. Future research should prioritize longer-term, head-to-head randomized trials that standardize vascular endpoints and explicitly test why macrovascular benefits can coexist with neutral or adverse microvascular responses across different fasting modalities and patient subgroups.