Copper supplementation in humans does not affect the susceptibility of lowdensity lipoprotein to in vitro induced oxidation (FOODCUE project)

The oxidative modification of low-density lipoprotein cholesterol (LDL) has been implicated in the pathogenesis of atherosclerosis. Copper (Cu) is ess ential for antioxidant enzymes in vivo and animal studies show that Cu defi ciency is accompanied by increased atherogenesis and LDL susceptibility to oxidation. Nevertheless, Cu has been proposed as a pro-oxidant in vivo and is routinely used to induce lipid peroxidation in vitro. Given the dual rol e of Cu as an in vivo antioxidant and an in vitro pro-oxidant, a multicente r European study (FOODCUE) was instigated to provide data on the biological effects of increased dietary Cu. Four centers, Northern Ireland (coordinat or), England, Denmark, and France, using different experimental protocols, examined the effect of Cu supplementation (3 or 6 mg/d) on top of normal Cu dietary intakes or Cu-controlled diets (0.7/1.6/6.0 mg/d), on Cu-mediated and peroxynitrite-initiated LDL oxidation in apparently healthy volunteers. Each center coordinated its own supplementation regimen and all samples we re subsequently transported to Northern Ireland where lipid peroxidation an alysis was completed. The results from all centers showed that dietary Cu s upplementation had no effect on Cu- or peroxynitrite-induced LDL susceptibi lity to oxidation. These data show that high intakes (up to 6 mg Cu) for ex tended periods do not promote LDL susceptibility to in vitro-induced oxidat ion. (C) 2000 Elsevier Science Inc.