Introduction to Antioxidants and Free Radicals


What Are Free Radicals?




When scientists talk about the effect of free radicals on cellular components, such as DNA or mitochondria, they say the structure has been "oxidized." When free radicals oxidatively damage cell structures, the health of the entire cell is weakened. For more information on how free radicals work, see Technical Appendix A at the end of this article.

Antioxidants Are Anti-Aging




Carotenoids are a major class of phytonutrients responsible for many of the red, orange, and yellow hues of plant leaves, fruits, and flowers. Examples of carotenoids include beta-carotene, alpha-carotene, lutein, and lycopene. These are natural fat-soluble pigments found principally in plants and algae, where they play a critical role in protecting and aiding the photosynthetic process.

Carotenoids are sometimes referred to as the "first line of defense" because they provide critical antioxidant protection to cells and other antioxidants by absorbing or "blotting up" large amounts of attacking free radicals. This absorption allows other antioxidants to function in more specialized ways. While carotenoids have typically not been included in skin care products due to their intense color, a unique form of colorless carotenoids with enhanced UV protective properties has been discovered.

Just as plants produce lipid soluble carotenoids to protect cellular structures composed mostly of lipids, plants also produce phenolic compounds to guard their tissues against free radical damage. These compounds can be fat- or water-soluble. Examples of phenolic compounds include hydroxytyrosol in olive oil and polyphenols found in strawberries.

Flavonoids are a class of polyphenolic compounds. It is estimated that there are over 600 different flavonoids present in foods and beverages. Some common flavonoids are catechins (green tea), quercetin, proanthocyanidins (grape seed extract), and soy isoflavones. Flavonoids provide increased cell protection for the DNA as well as promote the repair of DNA damaged by free radical oxidation.

Vitamins and Other Key Antioxidants

The core of the antioxidant network includes powerful antioxidants such as CoQ10 and vitamins C and E. In addition to their free radical fighting properties, these antioxidants have other functions that allow them to make critical contributions to our health and longevity.

Vitamin E is one of the body's most important fat soluble antioxidant nutrients. Vitamin E protects healthy cell membranes (largely composed of fatty acids) from oxidative free radical damage. There are eight natural forms of vitamin E (four tocopherols and four tocotrienols).

Vitamin C (ascorbic acid) is water soluble, enabling it to scavenge free radicals in aqueous (watery) environments, such as the inside of our cells and extracellular body fluids. Vitamin C works synergistically with vitamin E to quench free radicals and also works to regenerate vitamin E, keeping it active.

Other key antioxidants include coenzyme Q10 and alpha lipoic acid. Alpha lipoic acid is a naturally occurring molecule in plants and animals that has the ability to neutralize free radicals. Another important function of alpha lipoic acid is its ability, when applied topically, to improve skin tone and texture. Coenzyme Q10, or CoQ10, is found naturally in our cells; however, CoQ10 levels in the body have been shown to decline after age 20. Highly concentrated within the cell's mitochondria, CoQ10, like vitamins C and E, quenches free radicals and helps regenerate other antioxidants. For more information on how antioxidants work, consult Technical Appendix B at the end of this article.

In summary, free radicals are highly unstable, reactive molecules that damage the DNA within cells. This damage is passed on to newly replicated cells. Over time, genetic damage builds up and interferes with healthy cell function. Fortunately, antioxidants, the natural compounds found in fruits and vegetables, neutralize the negative effects of free radicals. Some key antioxidants include vitamins E and C, carotenoids, flavonoids, alpha lipoic acid, and CoQ10. Antioxidants are a true defense in fighting the assault of free radical damage on healthy cells.

Technical Appendix A: How Free Radicals Function
Free radicals are unstable, highly reactive molecules because they have one or more unpaired electrons. In order to stabilize themselves, free radicals seek ways to pair their unpaired electrons. To do this, they may steal electrons from other stable molecules. This can cause the secondary molecule to become a reactive, unstable free radical. Having lost its electron, these secondary molecules become free radicals that in turn steal electrons from other molecules. This cascading effect sets off a free radical chain reaction of molecular destabilization. Free radical chain reactions can continue indefinitely, ultimately damaging millions of cells. Much of what is damaged by free radicals are DNA, lipids, and proteins that makeup the cellular structures in our bodies. Among other serious consequences, this damage leads to side effects associated with skin aging, such as poor cell renewal, and slowed collagen and elastin production.

Technical Appendix B: How Antioxidants Work
Antioxidants are stable molecules with electrons to spare; they also have the ability to receive extra electrons. Antioxidants are nature's defense against the damaging effects of free radicals. They guard cellular structures and DNA against electron-scavenging free radicals. Antioxidants can donate or receive electrons to neutralize free radicals, stopping the cascading effect of oxidation.

Lester Packer

Known as the father of antioxidants, Dr. Packer has advised both Nu Skin and Pharmanex on the development of products featuring the powerful antioxidant CoQ10. As the world's foremost antioxidant research scientist, he has published more than 800 scientific papers and 100 books on every aspect of antioxidants and health. A professor and senior researcher at the University of California at Berkeley for 40 years, Dr. Packer established a research laboratory in the Department of Molecular Pharmacology and Toxicology at the University of Southern California. Recently, he was appointed as a distinguished professor and scientific advisory board member at the Institute for Nutritional Sciences, a branch of the Chinese Academy of Sciences.