What Are Antioxidants and How Do They Work?

What Are Antioxidants?

This is a curious question that's still puzzling scientists - but we're making significant progress! I'll try to outline some of the basic functions of antioxidants along with their drawbacks. So, let's get started!

So what are antioxidants, you ask?

Antioxidants are substances that neutralize the damaging effects of free radicals by preventing oxidation reactions. In other words, they either prevent the passage of electrons to oxygen or remove the product of the reaction. Wait, free radicals?

O.K., let's start over! Free radicals are molecules or atoms that contain an unpaired electron which makes the extremely reactive with other free radicals or other kinds of molecules, resulting in a chain reaction that damages body tissues. Your body can create these on accident through a variety of processes, most notably during the process of oxidative phosphorylation.

This is the process by which metabolites (such as carbohydrates, simple sugars or fats) are broken down for energy in the mitochondria of each body cell in the presence of oxygen molecules.

When electrons move down the electron transfer chain in the mitochondria (from NADH or FADH₂), some of these electrons can escape the system and interact with oxygen molecules that are floating around and waiting for their turns to be converted into water...

This unpaired electron can then go on to react with other free radicals, DNA, proteins or other tissue components causing significant damage with a multitude of different results, from premature aging to heart disease to cancer.

Damaging free radicals can also be obtained from the environment via environmental pollutants, UV damage and, unfortunately, smoking.

Now that we have this background information, let's try this again...

So, what are antioxidants?

Antioxidants are substances that help remove these free radicals from your system, thereby neutralizing their effects. There're several enzymatic systems that help remove free-radicals such as glutathione reductase. However, beta carotene (lycopene), vitamin C and vitamin E help maintain these systems and help remove even more free radicals from the system.

What are Antioxidants?: Vitamin E!

As with other nutrients, too much of any antioxidant has detrimental effects on the body. The main reason for this is that antioxidant supplements in the form of a pill don't act as antioxidants when they enter the body. For example, vitamin E in the past was given as an anticoagulant (an agent that prevents blood clotting, a way to prevent an imminent heart attack). This is no longer done, however, for a multitude of reasons.

An individual taking megadoses of vitamin E will experience symptoms of taking a load of aspirin instead of the desired "antioxidant" effect (such as excessive bleeding if you get a cut). Furthermore, the progression of autoimmune diseases (such as autoimmune hemolytic anemia) may be promoted with excessive doses of vitamin E.

So, labeling this vitamin as an antioxidant is extremely misleading. This trait mainly exists when the vitamin is taken naturally from foods and not from pills. The exception in this case, however, are pharmaceuticals. There are preparations of vitamin E that are used medically to treat conditions such as Parkinson's Disease, Alzheimer's Disease and Lou Gehrig's Disease.

What are Antioxidants?: Vitamin C!

I feel it's a responsibility of mine to report the effects of vitamin C "antioxidant" effects. The idea is extremely misleading. Remember, it may be an antioxidant when taken from foods, but not from pills.

The fact is that vitamin C is highly pro-oxidant while in the presence of iron. This, in combination with individuals who genetically inherit larger iron storages, can causes problems such as iron overload. Vitamin C acts to mobilize iron from its storage site, resulting in an excessive iron concentration in the blood. This situation can be lethal as large blood iron concentrations can result in cardiac failure (this is obviously an extreme case). Some milder effects may be shortness of breath after a large dose as well as kidney stones when taking large doses over long periods of time.

In short, taking vitamin C will be detrimental if you have large iron storages while it may be helpful if you don't have large iron storages. It's imperative to have your blood iron checked by a physician before taking any sort of vitamin C supplement for any reason.

What are Antioxidants?: Beta-Carotene!

Beta-carotene is a less-toxic form of vitamin A that we normally get in the diet from green vegetables and yellow/orange vegetables (in fact, if you eat too many carrots, your skin may turn orange! Sometimes this is confused with jaundice, a sign of liver disease).

Vitamin A is important for supporting the normal growth and differentiation of cells, a process that goes awry in the development of a tumor (cancer). It's been postulated that an increased intake of vitamin A in the diet may ward off these tumors.

The problem is that vitamin A is fairly toxic when taken in large amounts, especially to a developing fetus. Scientists are developing synthetic forms of the vitamin (not obtained in the diet) that may help ward off cancer in a safer manner.

The upside with beta-carotene is that it's much less toxic in large amounts than vitamin A, making it a likely alternative. Studies showed, however, that beta-carotene (eating tons of carrots) alone cannot provide much of a protective force against cancer.

A better answer are other molecules in the same family of carotenoids (there are hundreds). These types of compounds are abundantly found in tomatoes and show a greater ability to prevent cancer. In other words, the other carotenoids trap and neutralize damaging free radicals while beta-carotene alone does not. Taking beta-carotene pills for antioxidant action is probably a waste of time and money!

Much more research must be done to make a conclusion about the antioxidant effects of vitamin A and the carotenoids.

What About Selenium as an Antioxidant

It's important to say up front that taking excessive selenium is extremely toxic. Selenium is a trace metal, essential mineral and potent antioxidant. It's likely that a normal diet contains enough selenium to provide optimal protection. But, you and I both know how marketing likes to put a "spin" on things. Supplement companies will tell you that you need extra selenium for your prostate or ovarian health. The fact is you don't - you get plenty from the diet.

Antioxidant Deficiency

There's rarely a diet out there that's so low in vitamin E, beta carotene or vitamin C that has the potential to result in a deficiency. Therefore, taking a supplement of these substances for this reason wouldn't really be helpful for anyone. I know the concept you've been fed is to prevent cancer...but let's face it, if you're eating a healthy diet and possibly taking daily vitamin supplements, you likely have nothing to worry about.

So, what should you do?

Eat your fruits and vegetables! Make sure you're getting enough exercise and following a balanced diet. You'll never be deficient in antioxidants if you continue to take care of your body.

The only time you might consider antioxidant supplements is if you're one of those individuals who workout vigorously a few times per month with inactivity in between workouts. This situation may increase free radical damage. But remember, do not overdo it! And, the number one rule is...

Don't let the media influence your decisions! There's always going to be some company out there promoting the antioxidant effects of vitamins C, E or A, but be extremely wary of any of these claims before an official statement by the FDA is made concerning antioxidants. This is an extremely important point! Be wary of any claims made by any company at this point until proper FDA approval.

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