Antioxidants

Antioxidants are compounds used by the body to keep cells from being damaged by the oxidative stress of chemical reactions. The by-products of these oxidation reactions, free radicals, are the main cause of harmful chain reactions and are therefore removed or reduced by antioxidants. These compounds work simultaneously in complex systems and can be made [Page 150]in the body or obtained through dietary means. These molecules have proved to be quite effective in treating various diseases because they offer basic protection to cells throughout the body. However, some say that improper use could cause an antinutritional effect. The exact mechanisms and amount needed has not been completely determined.

Oxidation is a basic and ubiquitous process in the body whereby electrons are transferred from one compound to another. During this process, charged molecules called free radicals are formed. Oxidative stress is a result of unnecessary reactive oxygen species (ROS) being formed with charged oxygen molecules. Because cells cannot survive in a continuous oxidized state, antioxidants are used to counteract this process and help the cell return to chemical equilibrium.

Antioxidants can be compounds made by the body or can be acquired through dietary supplementation. In the body, these endogenous and exogenous antioxidants work together to reduce or prevent oxidative cell damage when needed. The major compounds of dietary antioxidants include vitamin A, vitamin C, vitamin E, selenium, and plant-derived chemicals. Recommended dietary sources include vegetables, fruits, tea, cocoa, wine, nuts, low-fat dairy products, and cereal grains.

Dietary antioxidants seem to have a vital role in reducing the chance or preventing the onset of various conditions such as cancer, heart disease, cognitive impairment, and eye diseases. The free radicals generated by the body seem to play a role in the natural aging process and aging seems to contribute to health problems due to the resulting oxidative stress. A high-fiber vegetarian diet with an assortment of vegetables and fruits seems to significantly reduce the incidence of cancer in general. Due to the complex composition of most fruits and vegetables, researchers have not been able to conclusively link an antioxidant-rich diet to decrease in cancer incidence. However, vitamin C was shown to have the strongest protective effect against stomach cancer and vitamin E showed some tumor-suppressing capabilities in animal studies.

In the case of heart disease, research has shown that intake of several different antioxidant vitamins could provide a protective effect against the oxidation of low-density lipoprotein (LDL) cholesterol, which leads to clogged arteries. Preventing this clogging could significantly lower the chance of getting a heart attack. Also, vitamin E in particular can potentially be used to reverse or prevent neurological diseases such as Alzheimer's and Parkinson's. Finally, the eye is a place for high levels of oxidation due to intense exposure to light. Antioxidants have been shown to neutralize such by-products that accumulate over time.

In specific circumstances, antioxidants create an undesirable effect on health. One trial showed that beta-carotene, a form of vitamin A, increased the risk of lung cancer in smokers. After exercising, free radicals are produced by the immune system to repair damaged tissue and excess antioxidant levels could potentially hinder this process. While we lack a complete understanding of antioxidants’ role in the body or in pharmacologic treatment, it is certain that they are an essential part of health.

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