Copper deficiency may be a leading cause of ischaemic heart disease

The burden of ischaemic heart disease (IHD) continues to grow in the developed world with a greater fraction of the population composed of older people. In the USA, heart disease is the leading cause of death overall and in those over 65 years of age.1 The most accepted theory for the cause of IHD remains high total or elevated LDL cholesterol, which in turn is due to a high intake of dietary saturated fat; yet this theory has come under increasing scrutiny in recent years. Indeed, recent meta-analyses have found no relation between dietary saturated fat consumption and the incidence of IHD.2 We may have been looking in the wrong places in our attempts to discern the cause(s) of IHD. Copper is an essential trace element that has been an overlooked factor in IHD. Numerous animal and human studies have demonstrated that copper deficiency can cause IHD and that copper supplementation or adequate dietary copper can improve many of the risk factors for IHD. Copper deficiency could be driving much of the current burden of IHD in the population. Copper intakes have been declining and it appears that a large fraction of the population does not even consume the recommended daily allowance (RDA) for copper3 (0.9 mg per day) let alone an optimal intake of copper (2.6 mg per day).4 Thus, it appears that much of the population is at risk of inadequate but especially suboptimal intakes of copper. Copper is involved in numerous biological processes, and its insufficiency or deficiency can to lead to many of the risks or manifestations of IHD, as we discuss below. ### Biological properties of copper Copper is involved in the functions of many copper-dependent proteins, including transcriptional regulators, chaperones, oxidoreductases, mitochondrial electron transport and free radical scavenging.5 Copper is also important for immune …