From Longevity Genetics to Precision Interventions: Integrating Nutrigenomics and Epigenetic Mechanisms of Ageing

Human ageing and longevity are increasingly understood as biologically integrated and heterogeneous processes shaped by interactions among genetic susceptibility, epigenetic remodelling, and environmental modulation. This narrative review examines these interconnections within a nutrigenomic framework, with particular emphasis on how inherited variation and epigenetic plasticity may influence responses to ageing-related interventions. A structured literature search was conducted in PubMed, Scopus, Web of Science, and Embase, focusing on English-language studies published during the last 10 years. The review was organized into three major domains: (i) genetic determinants of longevity, (ii) epigenetic mechanisms of ageing, and (iii) intervention-responsive pathways relevant to precision geroscience. Current evidence supports a polygenic model of longevity in which loci such as FOXO3 and APOE show the most consistent human associations, while telomere maintenance, insulin/IGF-1 and mTOR signalling, sirtuins, Klotho, inflammatory mediators, and DNA repair remain biologically important but variably supported at the variant level. Epigenetic mechanisms, including DNA methylation drift, epigenetic clocks, histone modifications, chromatin remodelling, heterochromatin loss, and non-coding RNA regulation, provide an environmentally responsive interface linking genetic background to ageing phenotypes. Nutritional, pharmacological, behavioural, and circadian interventions converge on overlapping molecular pathways involving AMPK, mTOR, FOXO, sirtuins, autophagy, mitochondrial maintenance, and inflammatory signalling, although human evidence remains heterogeneous and biomarker modulation should not be equated with clinically meaningful slowing of organismal ageing. Overall, this review highlights the value of integrating genetics, epigenetics, and intervention biology to support a more cautious and translationally relevant model of healthy ageing. It also underscores the need for precision nutrigeroscience approaches that account for tissue context, baseline physiology, and inter-individual molecular variability.