 Thirty adults aged 30-75 y will be randomized to either 4 gd of eicosapentaenoic acid or no drug for 12 weeks. Endothelial function will be measured at baseline and after 12 weeks. in a secondary aims, we will evaluate effects of eicosapentaenoic acid EPA on plasma levels of c-reactive protein, oxidized low-density lipoprotein cholesterol, and endothelin-1. 