The notion that antioxidant nutrients, such as vitamins E, C, and others could aid exercise recovery first appeared in a 1954 animal study. The body is constantly producing byproducts of oxygen metabolism, which is unavoidable unless you stop taking in oxygen. Many of these oxygen byproducts are produced in the portion of cells that uses the most oxygen, namely the mitochondria. Oxygen is processed in the mitochondria through the electron transport system, which produces the most immediate source of energy in the body, ATP. These oxygen byproducts are called free radicals and reactive oxygen species (ROS). A free radical is simply an unpaired electron. Electrons come in pairs, and free radicals are always trying to pair up with already paired electrons. When that happens, everything from cell membrane damage to cardiovascular disease to cancer can occur. Any type of fat in the body is particularly susceptible to free radical attacks. Cell membranes are largely composed of fat and cholesterol, and the brain contains 60% fat, largely as DHA, an omega-3 fatty acid. When free radicals attack these organs, damage is incurred. This can lead to disease. One example of this is low-density lipoprotein cholesterol or LDL. LDL is often referred to as the "bad" cholesterol because it's linked to the onset of atherosclerosis, which in turn is a major risk factor for heart attacks and strokes. But LDL is only dangerous when it's oxidized. When it's not oxidized, it merely acts as a transport vehicle for cholesterol in the blood. The 1954 seminal study found that free radicals are produced throughout the body, including blood, brain, liver, and muscle.
In 1957, the Free Radical theory of aging was proposed. This theory stated that the major cause of aging was oxidation caused by free radicals. This opened the door to the sale of various dietary antioxidant supplements, with vitamins C and E being the most popular. But what was overlooked was the fact that the body provides its own built-in oxidant defense system. This defense system consists of enzymes, such as superoxide dismutase, catalase, and glutathione. But these enzymes all contain nutrient precursors, such as in superoxide dismutase, the trace minerals zinc, and manganese, while glutathione is a tripeptide consisting of three amino acids. An important point is that if you do not consume the nutrient precursors for these endogenous antioxidant defense systems, they will not function at an optimal rate. But they do have a backup, and that is the dietary antioxidants, such as various vitamins and minerals. While the built-in enzyme antioxidants are far more potent than any dietary antioxidant in quenching free radical activity, many studies show that the production of these enzymatic antioxidants declines with age. When that happens, you are at a greater risk of acquiring diseases associated with increased oxidation, such as cancer, cardiovascular disease, and degenerative brain disease, including Alzheimer . . .