Numerous studies have shown the beneficial effects of fruits, vegetables and omega-3 fatty acids in reducing the risk of cardiovascular disease. The cardioprotective properties may be attributed to the bioactive compounds found in fruits and vegetables called flavonoids. High concentrations of flavonoids with antioxidant activity are found in blackcurrant extract. Flavonoids like omega-3 fatty acids may improve vascular function by increasing the bioavailability of nitric oxide, a potent vasodilator. PCSO-524 (Pernacanaliculus supercritical oil) is of particular interest as a rich source of omega-3 fatty acids derived from the green-lipped mussel. The objectives of this study are to determine the effects of blackcurrant extract, PCSO-524 or the combination of blackcurrant extract & PCSO-524 on endothelial function (flow-mediated brachial artery dilation) and arterial stiffness (cardio-ankle vascular index) as indicators of cardiovascular risk and atherosclerosis. These indices also provide an assessment of structure and function of the artery. The effects of the supplements on biomarkers of vascular health (endothelial dysfunction, inflammation, injury, oxidative stress, nitric oxide status), lipids and fatty acid profile, and flavonoid profiles will also be determined. In a randomized, double-blind, placebo-controlled trial, one hundred twenty-two healthy older adults (ages 55-75) will be given either blackcurrant extract (1000 mg), PCSO-524 (400 mg), or blackcurrant extract (1000 mg) & PCSO-524 (400 mg) daily for 8 weeks while consuming their usual diet. The study will include 4 visits at 8 week intervals consisting of treatment, washout and placebo phases.