Free Radicals

As I quickly learned, oxygen can be a dangerous friend. The human body requires sample amounts of oxygen for metabolism, the breakdown of nutrients to create the energy for growth and other body activities. Energy is essential for every physical activity, from breathing to thinking, from having sex to keeping our hearts beating.

Oxygen is the fuel that turns on energy production. Without oxygen, we could not make energy. Yet the production of energy can wreak havoc in the body because it also produces free radicals.

Free radicals are unstable molecules that can damage cell structures and can ultimately lead to cancer, heart disease, and numerous other illnesses. As I will explain later, Alzheimer's disease, Parkinson's disease, diabetes, cataracts, arthritis, and many other ailments associated with aging are caused or aggravated by free radicals.

Before you can fully understand The Antioxidant Miracle, you need to know more about the nemesis of antioxidants: free radicals. As the adage goes, wherever there is smoke, there is fire. Similarly, wherever there is disease and destruction, there are free radicals. The flip side is that wherever there is life, there are free radicals. We could not exist without them. We have only just begun to fully appreciate the role of free radicals in the body.

Every time we try to remember a fact or are sexually aroused or are battling a cold, we are putting free radicals to good use. Free radicals perform many critical functions in our bodies, from controlling the flow of blood through our arteries, to fighting infection, to keeping our brains sharp and in focus.

Similar to antioxidants, some free radicals at low levels are signaling molecules—that is, they are responsible for turning on and off genes. Some free radicals, such as nitric oxide and superoxide, are produced in very high amounts by our immune cells to "poison" viruses and bacteria. Some free radicals kill cancer cells, and in fact, many cancer drugs are actually designed to increase the production of free radicals in the body. The role of nitric oxide is so important that in 1998, the Nobel Prize in Physiology and Medicine was awarded to the scientists who discovered nitric oxide's role as a signaling molecule in the cardiovascular system.

Clearly, we need free radicals for our survival. Yet, in less than a split second, free radicals can turn on us, make us sick, and age us before our time.

Whether it is sunburn, a heart attack, a stroke, or an inflammatory illness such as arthritis, free radicals are a factor in either the onset or progression of these conditions. Even the aging process itself is linked to free radicals.

Free Radicals are Everywhere

In order to understand what free radicals are, you need to know a bit about the human cell, where the tug-of-war between free radicals and antioxidants is played out every second of every day. Like everything else in the universe, cells are composed of smaller units called atoms. Each atom contains a center or nucleus that is surrounded by electrons. Two or more atoms may bind together by sharing electrons. Biological oxidation, the process of making energy, involves moving electrons from one oxygen molecule to the next. However, sometimes an electron escapes. This "free" electron is called a free radical.

Free radicals constantly form almost everywhere in the body at an astonishing rate. If free radicals are not quickly trapped, they can cause a great deal of trouble. Free radicals can attack and oxidize DNA, the genetic material that controls cell growth and development, which can increase the likelihood of cancer. When these unstable molecules target fat molecules traveling in the bloodstream, they set the stage for heart disease and stroke. Therefore, free radicals can promote the downward spiral of disease and premature aging.

Free Radicals and Chronic Inflammation

Inflammation is caused by the overproduction of free radicals in a specific area of the body. It is responsible for about 30 percent of all cancers and is a contributing factor, if not the cause, of numerous other medical problems.

The inflammatory response is also a factor in arthritis, an umbrella term for more than 100 different diseases that produce either inflammation of connective tissue (the joints and tendons) or degeneration of the articular cartilage, a wearing down of the protective covering that cushions the ends of bones, allowing bones to rub together without causing damage to the joints.

When joints become arthritic, they become inflamed and enlarged, interfering with the normal flow of blood. For example, in the case of an arthritic knee, when you bend the knee, you cut off blood flow to the area. As you may remember from my description of stroke, when blood flow is cut off, it sets in motion a chain of events that will lead to a burst of free radicals when the blood flow returns, which is precisely what happens when you release the knee. The proliferation of free radicals causes the area to become even more inflamed, contributing to the degeneration of the joint, which becomes more swollen and worn down.

Free radicals can be enemies or friends, but we have to interact with them the right way, or they can quickly turn against us. The key is to maintain the antioxidant advantage, the optimal balance between free radicals and antioxidants. We can achieve the antioxidant advantage by consuming adequate amounts of antioxidants in the form of food and supplements, and by limiting exposure to "pro-oxidants" in the environment that can harm us.

FREE RADICALS AND STROKE

Stroke is an example of how free radicals do their dirty work, and how they can make a bad situation even worse. A stroke occurs when blood flow is cut off or restricted to a particular region of the brain. It could be caused by a blood clot, or by a piece of debris that breaks off from an atherosclerotic plaque and blocks the artery delivering blood and oxygen to the brain. Whatever the cause, the results can he devastating. You may be surprised to know that much of the actual damage to the brain does not occur when it is being deprived of blood and oxygen, but immediately following the stroke, when the blood flow is restored. This is called reperfusion injury. When it happens, there is a burst in production of superoxide free radicals that can attack nearby tissue, resulting in permanent brain damage.

The situation can get even more serious if in the process of damaging brain tissue, iron is released into sites where it is normally tightly bound or controlled. Iron is the most abundant mineral in the body and it is vital for life, but iron is not allowed to roam freely throughout the hotly. It is held tightly bound to proteins, carried to tissues where it is deposited into storage sites, and closely guarded.

The body goes to great pains to contain iron. Free iron — that is, iron that is not bound to a protein — is potentially very dangerous because it can trigger free radical reactions. More free radicals are the last thing brain tissue needs to contend with after a stroke. High accumulations of iron in the brain have also been associated with degenerative diseases such as Alzheimer's and Parkinson's. Not surprisingly, there have also been several studies that have linked high blood levels of free iron to an increased risk of heart disease and stroke.