Antioxidant plays a very important role in the body defense system against Reactive Oxygen Species (ROS). The free radicals also play an important role in combustion, atmospheric chemistry, biochemistry and biotechnology including human physiology. Fats and oils are energy sources that are composed mostly of triacylglycerols. Lipid ptofile are risk indicators of coronary heart disease. Various types of lipoproteins exist, but the two most abundant are Low-density Lipoprotein (LDL) and High-density Lipoprotein (HDL). Lipid peroxidation is the introduction of a functional group containing two catenated oxygyen atomsinto unsturated fatty acids in a free radical reaction. Life in oxygen has led to the evolution of biochemical adaptations that exploit the reactivity of Active Oxygen Species (AOS). Antioxidant enzymes are an important protective mechanism ROS. This paper highlight the functions of antioxidants in the blood and selected organs associated with health.