Stabilized oils including an edible oil and an antioxidant composition comprising cα-lipoic acid and least one of ascorbic acid, ascorbyl palmitate, green tea extract, lecithin, and rosemary extract or at least one of 1,2,4-benzenetriol, carnosic acid, dihydromyricetin, dihydrorobinetin, epigallocatechin, gallic acid, 3-hydroxytyrosol, myricetin, and nepodin, and methods of preparing such stabilized edible oils. The stabilized oils may have an Oxidative Stability Index (“OSI”) at 110° C. of at least 30 hours.