Effectiveness of Omega-3 Supplementation on Arterial Stiffness: A Systematic Review

Background/Objectives: Evidence linking omega-3 intake to reductions in arterial stiffness remains inconsistent. This systematic review aimed to evaluate and synthesize evidence on the effectiveness of omega-3 supplementation in reducing arterial stiffness as measured by pulse wave velocity (PWV). Methods: Two search iterations were conducted in Scopus, PubMed, and Web of Science. The search was conducted through 2025. The search terms were “omega-3” AND “pulse wave velocity”. No filters for language or study type were applied. Results: In this set of 20 randomized controlled clinical trials, omega-3 supplementation had heterogeneous effects on arterial stiffness measured by PWV. Slightly more than half of the studies reported significant reductions in PWV, while the remaining studies reported no statistically significant changes. This heterogeneity may be explained by differences in study population, dose, and treatment duration. Favorable effects were more commonly observed in studies using moderately high omega-3 doses (approximately 1.8–4 g/day), interventions lasting ≥12 weeks, and populations with metabolic disorders or higher vascular risk. In contrast, studies using low doses, acute interventions, or plant-based omega-3 more frequently reported null results. Conclusions: These findings indicate that population characteristics, dose, and intervention duration should be considered when designing future trials and clinical recommendations.