Free Radicals

Free radicals are molecules with electrons that are unpaired. Molecules are basic building blocks in nature, such as oxygen, fatty acids, amino acids, glucose, and DNA. Molecules are held together by electrons. Stable molecules have electrons that are in pairs, like a buddy system. But if a molecule has an electron that does not have a partner, it becomes unstable and reactive-a free radical. It will steal an electron from a stable molecule.

Once the stable molecule loses an electron, it becomes another free radical. This second free radical will steal an electron from a third molecule, and a destructive cycle begins. Each time a molecule loses an electron, it is damaged and will damage another molecule.

Free radicals come from three sources - our bodies, the environment, and free radical chain reactions.

Our bodies form free radicals every moment. Living cells need energy to live. This energy comes from reactions involving various substances and oxygen. During this process, intermediates of oxygen are formed, including superoxide and hydroxyl radicals. These intermediates are free radicals. Exercise, illness, and certain medication increase oxygen-related reactions in our bodies, consequently increasing the number of free radicals formed.

Moreover, our immune systems specifically produce free radicals to destroy bacteria and viruses. When we are invaded by harmful microorganisms and our immune systems work overtime, tremendous numbers of free radicals are produced to try to overcome the infection. During these times, controlling the excessive flood of free radicals is vital to protect healthy tissues from damage.

Free radicals are also important in producing vital hormones, or chemical messengers, in the body. Some free radicals activate certain enzymes that produce a wide variety of substances such as prostaglandins, the body's chemical regulators.

Clearly, free radicals are important for health. Without them, we would not be able to produce energy, fight off infectious agents, or produce the chemicals the body needs. Thus, it is very important to understand from the beginning that free radicals are not all bad. Only excessive and uncontrolled amounts of free radicals can damage the body.

The second source of free radicals is the environment. Air pollution, tobacco smoke, excessive radiation, toxic waste and runoff, herbicides, and pesticides all form free radicals, which we inhale or ingest. For instance, ozone is an extremely reactive air pollutant resulting from vehicle exhaust. When we breathe in ozone, it forms free radicals in our lung tissue. Moreover, since blood is constantly being pumped to the lungs for oxygen, ozone-induced free radicals may involve blood cells, diminishing the oxygen supply to the body.

Many of the health woes of the past few decades may be related to the increasing use of dangerous chemicals and technologies, leading to vastly more free radical production than was present a few generations ago. Hopefully, the "green movement" toward cleaning and preserving our environment will result in tremendous reduction of free-radical sources in the environment, substantially decreasing chronic and acute diseases. Earth will treat us well if we treat her well.

Finally, free radicals form other free radicals in chain reactions. One free radical produces a second, which produces a third, and so on. If uncontrolled, cellular damage can result. This domino effect is what makes free radicals so dangerous. Although a free radical regains its electron by stealing it from a stable molecule, it does not regain its original form and function; it is damaged. So, it's not like passing a hot potato for someone else to worry about; it's more like a spreading fire: something that is burned is never the same again.

Damage on a cellular level

Consider a healthy cell. It has membrane proteins, which act as fingerprints of the cell, so that other cells can recognize it. There are membrane lipids, arranged in a neat bi-layer, that is, one layer's lipids face out of the cell, and one layer faces in. The membrane lipids are distinct and separate from each other, yet tightly packed in order to form the cell membrane, which is the protective coat of the cell. The healthy cell also has a nuclear membrane, which sets off the cell's control center, the nucleus. Inside the nucleus is housed vital genetic material, such as DNA, in nice, neat double helices. And of course, a host of other substances make up the healthy cell.

Free radicals can cause the following devastation:

• Break off the membrane proteins, destroying a cell's identity.
• Fuse together membrane lipids and membrane proteins, hardening the cell membrane and making it brittle.
• Puncture the cell membrane, allowing bacteria and viruses easy entrance.
• Disrupt the nuclear membrane, opening up the nucleus and exposing genetic material.
• Mutate and destroy genetic material, rewriting and destroying genetic information.
• Burden the immune system with the above havoc, plus threaten the immune system itself by undermining immune cells with similar damage.

This messy picture gets messier, because cellular damage can accumulate to become full-blown disease states. Just as one tiny nail on the freeway can cause a major catastrophe, so a free radical can cause and worsen serious disease conditions, such as atherosclerosis, heart disease, cancer, AIDS, cataracts, skin cancer, aging.