Numerous articles have been written about how oxygen is both critical to life and terribly destructive at the cellular level. One of the clearest explanations of how oxygen is damaging came out of USC many years ago, an excerpt of this article is below. Concentrated oxygen can be medically necessary, and life-saving. When this is the case, the benefits certainly outweigh the detriments of additional oxidative stress damage.
Athletes, especially endurance athletes, metabolize far more oxygen than a normal person. Even though healthy athletes have more capacity to repair than the rest of us, overexertion and endurance training and competition can tip the scale in favor of damage. This can result in illness, performance decline, and accelerated aging. Why this is the case is explained in The Oxygen Irony.
The Oxygen Irony
Oxygen is a relatively small element—number eight on the Periodic Table and for those who remember their high school chemistry that means it has eight protons or positively charged particles. Oxygen is highly reactive and electrically charged. Electrically charged atoms strive to become neutral, to have a particular number of electrons in their outer shells. Each atom of oxygen, with six electrons, needs two more to be complete. That is why it will eagerly combine with any electron-donating atom—hydrogen, for instance—whenever itis given the opportunity. In the human body, of course, it is given that opportunity on a breath-by-breath basis. Each time a cells burns its oxygen fuel to create energy, it also creates freewheeling oxygen atoms known as oxygen free radicals. Therein lies the problem. Oxygen is not discriminating about what other molecular structures it might destroy in its quest to become electrically whole. If there are electrons to spare in a protein molecule, or in the fats that make up a cells’ membrane, or even in the DNA that is crucial to the functioning of our cells and our bodies, oxygen atoms will grab them and change them. This constant cellular wear and tear due to the ravages of oxygen is so pervasive that it has been given a name: oxidative stress. And like its psychologically based cousin, oxidative stress can wear down a body over time. Indeed, the biological consequences of this sort of electron scavenging can be found at the root of the normal process of aging. But it also has a part in cancer. Heart disease. Parkinson’s disease. Name the condition, and somewhere down the line, oxygen free radicals are likely to play a role.
Excerpt from Lori Oliwenstein’s article “The Oxygen Irony: Oxygen, the life force found in every breath, also is one of the human body’s most destructive invaders.” USC Health Magazine, 2002.