Dietary iron elevates LDL-cholesterol and decreases plasma antioxidant levels: influence of antioxidants.

High body iron and LDL-cholesterol concentrations, and antioxidant deficiency, are regarded as risk factors for ischemic heart disease. Iron is well known for causing oxidative damage and antioxidants for their beneficial effects on radical scavenging. It is, however, unknown whether or not dietary iron causes depletion of plasma antioxidants; causes lipid peroxidation; alters HDL- and LDL-cholesterol, and triglyceride concentrations. Rats received diets differing only in iron concentration--15 mg/Kg, 35 mg/Kg, 150 mg/Kg or 300 mg/Kg diet. The second group of rats received antioxidants (alpha-tocopherol and beta-carotene) in their drinking water. Increasing dietary iron increased plasma lipid hydroperoxide and LDL-cholesterol concentrations, but did not affect HDL-cholesterol or triglyceride concentrations. It decreased antioxidants, alpha-tocopherol and retinol. Antioxidant supplementation inhibited the above changes.