Antioxidants and Nutrition

Understanding Basic Antioxidant Science

Q. What are antioxidants?

Since the earliest times of the food production industry scientist have observed that common foodstuffs when left exposed to normal room conditions deteriorated over time leading to spoilage and waste. Results from scientific experimentation suggested that it was the oxygen in the air that caused foodstuffs to deteriorate. In looking for means to prevent or preserve common staple foodstuffs from degradation or spoilage, trial and error research ultimately lead to the discovery of certain natural substances that increased foodstuff stability. Based on their observations and results these early scientist concluded that these natural substances must contain chemical components that reacted directly with oxygen, hence the name antioxidant was born. Today, we now know from many years of ongoing experiments and analytical evaluations that most antioxidants (A.O.) do not directly react with oxygen but instead react with chemical molecules called free radicals or reactive oxygen species (ROS). Thus, antioxidants (A.O.) are chemical substances that deactivate, terminate, or consume free radical or reactive oxygen species (ROS molecules).

Q. What do you mean by free radical and reactive oxygen species (ROS)?

A free radical is a chemical substance or molecule that has at least one reactive non-bonded electron (free electron). A reactive oxygen species (ROS) is a chemical substance or molecule that contains at least one oxygen atom that has a reactive non bonded electron (free electron). ROS generally can be formed in the human body by the following physiological pathway (1) decomposition of the naturally occurring biochemical molecule hydrogen peroxide (H2O2) via metal catalysis which produces, (2) hydroxyl radical ( OH•) and super oxygen anion radical ( •O2‾ ). Both ( OH•) and ( •O2‾ ) can further react with lipid molecules and amino acids to formed other ROS.

Q. Are ROS good or bad?

Reactive oxygen species (ROS) can be both good and bad. Many reactive oxygen species are produced in human physiological processes to initiate specific biochemical reactions that are necessary to maintain normal bodily functions. Some ROS are used to kill bacteria and viruses. However, unscheduled ROS formation and/or low levels of antioxidants in blood and certain body tissues could result in excessive ROS build up in our bodies which could cause abnormal immune responses that if not mediated will lead to sickness and disease.

Q. Where can we find antioxidants (A.O.) in nature?

Antioxidants can be found in plants (this would include the leaf, stem, fruit, flower, root, even the bark), animals, and in humans. These antioxidants are called naturally occurring antioxidants. There are also man-made or synthetic antioxidants.

Q. What are the differences between synthetic antioxidants and naturally occurring antioxidants?
Most synthetic A.O. is actually patterned after some form of a naturally occurring A.O. The main difference between synthetic A.O. and its natural A.O. look-a-like is that the synthetic A.O. generally comprise just one analog (type) of the naturally occurring A.O. molecules (e.g., Vitamin E d-alpha tocopherol). Synthetic antioxidants generally are made to mimic the structure of the most active analog of the naturally occurring A.O. Yet there are at least four active analogs of Vitamin E found naturally (alpha, beta, gamma, and delta). The presence of all of the isomers of Vitamin E helps improve overall total Vitamin E solubility and depending upon the nature of the ROS molecules the four isomers combined together can exhibit a greater A.O. Effect (Synergism) than any one of the individual A.O. used alone when trapping ROS. So natural antioxidants generally come as a group of analogs or isomers. Another example of natural A.O. would be Green Tea Extract. Green Tea Extract contains a class of compounds called polyphenols. The most active polyphenols of green tea extract are A.O. called catechins (EGCG most active). There are 3 more active isomers of catechins, EGC, EC, and ECG. It is important to know that natural antioxidant structures are indigenous to the plants, fruits, and vegetables from where they are found geographically. So you see natural antioxidants could vary widely by structure and activity.

Q. What are some examples of made-made antioxidants and naturally occurring antioxidants?

Some naturally occurring A.O. would be Vitamin C (Ascorbic Acid), Vitamin E d-Alpha and mix Tocopherols, Vitamin D 3, Ubiquinol, Co-Enzyme Q-12, Uric Acid, Citric Acid, L-Methionine, Cysteine, Alpha-Lipoic Acid, L-Glutathione( L-Glutamic Acid, L-Cysteine, Glycine), Thymol, Carvacrol, Eugenol, Squalane, Squalene, Pinenes, Limonene, the classes of Catechins, Tannins, Flavonoids, Catechols, and other substances to a lesser degree. Some examples of synthetic A.O. are BHT, BHA, Bis-Phenol, Hydroquinone, 2,5-Di-Tertbutyl Hydroquinone, Trolox, and N-Acetyl Cysteine. Synthetic A.O. generally mimics natural A.O. in activity but not solubility and safety. Note that citric acid, N-Acetyl cysteine, and other amino acids are not truly A.O. but prevent ROS formation by chelating metals (deactivation) that initiate the production of ROS.

Q. You mentioned earlier that antioxidants can be found in plants and in humans. What are functions of antioxidants in plants?

A.O. in plants helps protect plant natural oils from air oxidation. These natural oils in many cases help repel insects and other predators. Some natural oils acts as sex attractants. Many A.O. also have anti-microbiological activities. A.O. protects plants from harmful microorganisms.

Q What is the function of antioxidants in humans?

A.O. helps stabilize body functions (e.g. maintaining blood pH, participate in many catalytic reactions). A.O. keeps reactive oxygen species (ROS) in balance in the body. A.O. also is a part of our natural immune system. A.O. is used in our body to help detoxify infection that causes diseases and kill the organisms associated with them. Furthermore, A.O. also helps protect our blood circulation and heart function.

Q In your opinion do you think antioxidants can be used to ward off diseases and help fight infections?
Most definitely. Recent published data on many natural antioxidants strongly suggest that A.O. supplementation is helpful in fighting off diseases and speeding the recovery from infections associated with some bacteria and viruses.

Q. Are there any health signs or symptoms that may suggest that the effective level of antioxidants in a person may be insufficient?

Yes. Symptoms of weakness, persistent coughing, chest pains, skin dryness, dry mouth, possibly increase in normal blood pressure.

Q. What foods can we consume that will supply us with helpful antioxidants?

Vitamin C, Citric Acid: oranges, lemons, grapefruit, limes, vegetables; Vitamin E, Squalane, Squalene: nuts, fish, fish oils, bran or wheat foods (non processed); Polyphenols, Catechins, Procyanidins: grapes, pomegranates, cranberries, green tea, white tea, blueberries; Beta-carotene: carrots, sweet potatoes; Cysteine and L-Methionine: meats, eggs, vegetables

Q. Can antioxidants be harmful?

Based on what we know today probably not. But caution should be taken with synthetic A.O. Many synthetic A.O. when used at moderate levels for prolong periods have been reported to cause tumor promotion in mice and animal studies. Some A.O like BHT and BHA are metabolized to chemicals that sometimes mimic estrogens. Too much of these estrogen-like compounds could exhibit adverse health effects in both males and females. To a much lesser degree some natural A.O. may have unwanted side effects depending on consumption levels and the individual. Too much Vitamin C (>10g/day) combined with iron supplements could produce excessive amounts of ROS via the Fenton reaction. The presence of large amounts of ROS in the blood stream might disrupt the normal balance of the human immune response system, particularly in individuals who are anemic. Over consumption of Vitamin E(>5000IU/day) could lead to excessive A.O. storage in fat tissues. However, there exist no long-term clinical studies that suggest that the excessive intake of vitamin E supplements leads to adverse health effects in humans.

Q. Can the use of antioxidant supplements be used in our daily health regimes to maintain effective antioxidant levels needed for healthy activity?

Yes, I recommend that people do.

Q. Could you give us a brief summary of how man uses antioxidants in our everyday lives?

In plastic plates, plastic spoons, plastic forks, Tupperware, automobiles, rubber, tires, planes, electronics, computers, drugs, jams, jellies, beverages, toys, cosmetics, computer accessories, foods,( chips, breads, vegetables, meats,) building materials, implants, prosthetic.