Anit-Oxidants And Aging

Kerrod McNeal

Anatomy & Physiology

Antioxidants are molecules that inhibit the oxidation of other molecules. Oxidation is a type of chemical reaction in which oxygen is added to a particular element or compound. It can produce what are known as free radicals. Free radicals are atomic molecules with unpaired electrons. Free radicals are usually highly reactive and play a role in many chemical reactions such as combustion, atmospheric chemistry, polymerization, plasma chemistry, biochemistry, and human physiology. Human physiology is the study of the physical and biochemical functions of the body. This paper examines the physical function of aging and its correlation with the biochemical function caused by antioxidants.

Aging is a physical process that can be altered by environmental factors such as diet and lifestyle. There are many theories that try to explain why and how we age. Among them, is what is known as the free radical theory of aging. This theory states that organisms age because cells accumulate free radical damage with the passage of time. (Harman, 1956)

Free radicals are the by-products of what happens when oxygen is metabolized. They are also produced in response to toxins or trauma. By nature, these molecules look for a partner to bond with and attract the nearest stable molecule to capture its electron. When that stable molecule loses its electron, it then becomes a free radical, initiating a chain reaction that results in the disruption of a living cell. (Borak, 1999) Some free radicals are important for certain biological processes such as the intracellular killing of bacteria by neutrophil granulocytes. Free radicals have also been implicated in certain cell signaling processes. (Pacher, 2007) The most important oxygen-centered free radicals are superoxide, hydroxyl radical and nitric oxide. They are derived from molecular oxygen under reducing conditions such as rigorous exercise and from exposure to pollutants, radiation, UV light and smoking. And, during infection and chronic inflammation, massive amounts of nitric oxide and super oxide radicals form in immune cells to fight off bacteria and viruses.(Borak,1999) However, because of their reactivity, an excess amount of these same free radicals can cause damage in protein, lipid, brain, and DNA cells.

This disturbance in cell structure is believed to be a contributing factor of aging and the health problems associated with it, such as clogged arteries and chronic illness. Harman, in explaining his theory of aging, discussed the involvement of free radicals in the occurrence and susceptibility of disease. (Harman, 1982) Scientific studies are being conducted now that may implicate free radicals in Parkinson's disease, senile and drug-induced deafness, schizophrenia, arthritis, diabetes, atherosclerosis, and Alzheimer's disease. The free radical agents are even capable of producing mutations that cause oxidative damage in DNA that, over time, can lead to malignancies and cancer. The free radical theory of aging basically proposes that free radicals underlie the aging process itself.

To try to slow aging and the effects of it, scientists have been studying the effects of increasing antioxidant levels in individuals through diet and dietary supplements. It is believed that Vitamin C, Vitamin E, Vitamin A, and beta-carotene, and some enzymes play key roles in the body's defense mechanism to minimize free radical induced damage and to repair damage which has already occurred. These antioxidants, as they are called, neutralize free radical agents by donating one of their own electrons but at the same time remaining stable. This reduces the level of free radicals level in the body and in turn prevents further or future cell damage. It is also possible, according to Dr. Robert Cathcart, that massive intakes of antioxidants such as ascorbic acid (Vitamin C) "can quench disease processes". (Harman,1956)

Antioxidants can be found in varying amounts in foods such as vegetables, fruits, grain cereals, legumes, nuts, and even chocolate. Some antioxidants such as lycopene and ascorbic acid can be destroyed by long-term storage or prolonged cooking. Others are more stable, such as the polyphenolic antioxidants that are found in whole-wheat cereals and tea. (Knight, 2000) In general, processed foods have a lower antioxidant level than fresh and uncooked foods. This is since the preparation of these foods exposes them to too much oxygen. The following are a few antioxidants and an explanation of their health effects.

Vitamin C

Vitamin C (ascorbic acid) is needed for most bodily metabolic functions. It is mostly found in citris fruits but can also