Free radicals and oxidative stress

Free radicals, also known as "reactive oxygen species" (ROS), are atoms or atomic groups that contain unpaired electrons. Since electrons have a very strong tendency to exist in a paired rather than an unpaired state, free radicals indiscriminately pick up electrons from other atoms, converting those other atoms into secondary free radicals, and thus setting up a chain reaction that can cause substantial biological damage. To protect itself from the damaging action of free radicals, our bodies use substances called antioxidants, which are also often referred to as free radical scavengers.

Oxidative stress is defined as the state in which the level of toxic reactive oxygen intermediates (ROI) overcomes the endogenous antioxidant defences of the host (Bulger EM, Helton WS; 1998). This state results in an excess of free radicals, which can react with cellular lipids, proteins, and nucleic acids, leading to local injury and eventual organ dysfunction.

According to Dr. Denham Harmon, MD, PhD, the process of aging is caused by the indiscriminate chemical re-activity of free radicals leading to random biological damage. If the free radical overload becomes overwhelming, premature aging, and inflammatory and degenerative diseases result. His idea was confirmed by many practical experiments, and it is now considered a major theory of aging. Dr. Harmon's theory implies that antioxidants such as vitamin C and vitamin E, which prevent free radicals from oxidizing (removing electrons from) sensitive biological molecules, will slow the aging process. Dr. Harmon launched his theory by showing, for the first time, that feeding a variety of antioxidants to mammals extended their life spans.

Free radicals are implicated in more than 60 different diseases

In addition to premature aging, the destructive effects of free radical chain reactions may be conducive to the development of such widespread and serious health conditions as peptic ulcers, cardiovascular disease, diabetes, infertility, renal, liver and lung disease, inflammatory and autoimmune diseases, and cancer. Free radicals may damage DNA and cause it to reproduce incorrectly, too rapidly, or not at all. They can also change DNA to produce potential carcinogens.

Free radicals alter the functioning of the cell. While the cell is somewhat permeable to allow nutrients to enter and wastes to be removed, free radicals change this, causing leakage or clogging, and ultimately the death of the cell. Free radicals interfere with the structures inside cells that produce energy, and then leave the cells weak and defenseless.

Overall, it is now recognized that free radicals contribute to more than 60 diseases. We can help body to "scavenge" or "neutralize" free radicals before they cause harm by avoiding environmental toxins as much as possible and increasing antioxidant intake. Because antioxidant compounds are effective at very low concentrations, we can gain protection from even moderate dietary changes that increase antioxidant nutrients.