Impact of astaxanthin supplementation on blood pressure: A systematic review and meta-analysis of randomized controlled trials

• Astaxanthin supplementation had beneficial effects on diastolic blood pressure (DBP). • Reduction in DBP was stronger in non-healthy participants compared to healthy ones. • Astaxanthin supplementation reduced DBP in Asian populations more than non-Asians. • Astaxanthin supplementation did not considerably affect systolic blood pressure. This systematic review and meta-analysis on randomized controlled trials (RCTs) evaluated the impact of astaxanthin (AST) supplementation on blood pressure in adults. We conducted a comprehensive search using different electronic databases. Ten RCTs with 493 participants that reported the effect of AST supplementation on blood pressure in adults were included. AST supplementation led to a marginally decline in diastolic blood pressure (DBP) (mean difference (MD) = −1.21; 95 %CI: −2.51, 0.09), but not systolic blood pressure. In patients, AST supplementation reduced DBP by 2.77 mmHg (95 %CI: −4.34, −1.19). Also, assigning ≥ 12 mg of AST to adults resulted in a slight decrease in DBP (MD = −0.89; 95 %CI: −1.82, 0.04). AST supplementation significantly reduced DBP by 2.27 mmHg in participants from Asian countries (95 %CI: −3.71, −0.83). This meta -analysis of RCTs disclosed that AST supplementation could reduce DBP, especially with a dose of ≥ 12 mg/d supplementation, in patient individuals and in participants from Asian countries.