Nutrition expert Joseph Mercola, MD, greatly expands our understanding of free radicals, cell-damaging oxidative stress (typically elevated in ME/CFS and fibromyalgia), and antioxidants. First published May 16, 2011, this information is reproduced with kind permission from Dr. Mercola’s educational website (Mercola.com). See footnote* for links to much more.
How a Normal Body Process (Oxidation) Can Contribute
to More than 60 Diseases
By now, just about everyone has heard of antioxidants and knows they are an important dietary component. Even many drug-focused Western physicians will acknowledge the importance of antioxidants for your health, at least in a general sense.
But do you know specifically what antioxidants are, what they do in your body, and what types you need?
• In this article, I will try to broaden your understanding of the group of nutrients known as “antioxidants,” and hopefully increase your appreciation of their importance by helping you understand exactly what they do to keep you youthful and healthy.
• My secondary aim is to show why you need a wide variety of antioxidants to accomplish this goal, as opposed to taking mega doses of only one or two.
Antioxidants are crucial to your health, as they are believed to help control how fast you age by combating free radicals, which are at the heart of age related deterioration.
In his book The Antioxidants, Richard A. Passwater, PhD, explains how humans have one of the longest natural lifespans of the animal kingdom, and that this may in part be due to the wealth of antioxidants in our omnivorous diet. Our bodies produce antioxidant enzymes that are not found in many other creatures.
According to Dr. Passwater, “Our natural antioxidant processes compensate for one another, covering up momentary deficiencies by their overlap.” Before we dive into antioxidants, you must first have a basic understanding of free radicals, because free radicals are what make antioxidants so essential to your health.
What Do Rotting Apples, Rusty Bicycle Frames, and a Sunburn have in Common?
Your body produces free radicals as a result of normal metabolism and energy production. Free radicals are a biological response to environmental toxins, such as cigarette smoke, chemicals, sunlight, cosmic and manmade radiation, and even a key feature of pharmaceutical drugs. Free radicals are also produced when you have inflammation in your body and when you exercise.
A free radical is a highly reactive metabolite missing one or more electrons – it has at least one unpaired electron. This missing election is largely responsible for the process of biological oxidation. These “partial molecules” aggressively look to replace their missing parts by attacking other molecules.
These reactions are commonly referred to as “oxidation” reactions. A bio-gerontologist named Denham Harman first discovered the concept of free radicals in 1954, while researching an explanation for aging. There is a duality to oxygen. Without it we would all be dead in a few minutes, however if we have too much it will damage our tissues.
Oxidation is like biological rusting and similar to what occurs to an iron bar that is dumped in the ocean.
You can also see evidence of biological oxidation after cutting into an apple and watching it turn brown from exposure to the air. The rust on your bicycle frame and the green patina on your penny are additional common examples.
Free radicals seek to steal electrons from many of the proteins in your body and can also result in damage to your DNA and other cell structures.
But it actually gets worse.
Free radicals can have a snowballing effect in which molecule after molecule steals from its neighbor, each one becoming a new free radical once it’s been electron-robbed, leaving a trail of biological carnage…
Five Types of Free Radicals
Free radicals can be broken down into five types. The first four types come from oxygen atoms and are called Reactive Oxygen Species (ROS), but the fifth type derives from nitrogen:
1. Superoxide ion (O): An oxygen molecule with an extra electron that can damage mitochondria, DNA and other molecules.
2. Hydroxyl radical (OH): A highly reactive molecule formed by the reduction of an oxygen molecule, capable of damaging almost any organic molecule in its vicinity, including carbohydrates, lipids, proteins, and DNA. OH cannot be eliminated by an enzymatic reaction.
3. Singlet oxygen: Formed by your immune system, singlet oxygen causes oxidation of your LDL [low density lipoproteins].
4. Hydrogen peroxide (H2O2): Not a free radical itself, but easily converts to free radicals like OH, which then do the damage. Hydrogen peroxide is neutralized by peroxidase (an enzymatic antioxidant).
5. Reactive Nitrogen Species (RNS) (NO): Nitric acid is the most important RNS.
These various free radical species can damage DNA in different ways.
They can disrupt duplication of DNA, interfere with DNA maintenance, break open the molecule or alter the structure by reacting with the DNA bases. Cancer, atherosclerosis, Parkinson’s, Alzheimer’s disease, and cataracts are examples of diseases thought to result from free radical damage.
In fact, free radicals are implicated in more than 60 different diseases.
Lipids in cell membranes are quite prone to oxidative damage because free radicals tend to collect in cell membranes, known as “lipid peroxidation.” (The lipid peroxide radical is sometimes abbreviated as LOO.)
When a cell membrane becomes oxidized by an ROS, it becomes brittle and leaky. Eventually, the cell falls apart and dies.
This is akin to what happens when butter, vegetable oils or meat becomes rancid – and why manufacturers sometimes add agents to prevent that. How can this free radical pillage be stopped?
This is where antioxidants come in.
Antioxidants are Your Body’s Solution to Counter Excessive Free Radicals
An antioxidant is a molecule capable of inhibiting the oxidation of another molecule. Antioxidants break the free radical chain of reactions by sacrificing their own electrons to feed free radicals, without becoming free radicals themselves.
They are all electron donors.
Antioxidants are nature’s way of defending your cells against attack by reactive oxygen species (ROS). Your body naturally circulates a variety of nutrients for their antioxidant properties and manufactures antioxidant enzymes in order to control these destructive chain reactions. For example, vitamin C, vitamin E, carotenes, and lipoic acid are well-known and well-researched antioxidant nutrients.
Your body can manufacture some of these antioxidants, but not others. And your body’s natural antioxidant production tends to decline with age.
Fortunately, most of the vegetables you eat are loaded with potent phytochemicals that act as antioxidants. And the closer they are to being harvested, the more potent these antioxidants will be – which is why you should consume the majority of your fruits and vegetables RAW and locally harvested. If you eat vegetables that have been harvested weeks before, as is common in most grocery stores, you will not be reaping much of the potential benefit the food has to offer you.
Your body requires these important micronutrients to help you resist aging, generated by everyday exposure to pollutants in your food, water, and air. If you don’t have adequate antioxidants to help squelch free radicals, then oxidative stress tends to lead to accelerated tissue and organ damage.
Oxidative stress can be defined as the state in which your free radicals outnumber your antioxidant defenses.
They can also serve to shorten your telomere length, which many experts believe to be the most accurate biological clock we have.
ORAC Scores a Tool to Help You Rate Different Antioxidants
Scientists at the USDA have developed a scale for measuring an antioxidant food or supplement’s ability to neutralize free radicals, called ORAC score (Oxygen Radical Absorbance Capacity). The higher a food’s ORAC score, the more powerful it is in combating age-related degeneration and disease.
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If you want to look up an ORAC score, you can go to the ORAC value database. Keep in mind, however, that although ORAC can be a useful tool, some manufacturers have found a way to misrepresent ORAC values with deceptive practices which can lead you astray.
The best way to combat free radicals (therefore slowing aging down) is to make sure you get ample antioxidants in your diet. Your first and most important source will be from high quality organic locally grown whole foods. Wisely selected supplements have also been shown to be highly beneficial in addition to your food choices.
Enzymatic and Non-Enzymatic Antioxidants
Antioxidants can be categorized into two types:
1. Non-enzymatic antioxidants work by interrupting free radical chain reactions. For example, having vitamin E around may interrupt a chain of free radical activity after only five reactions, instead of its snowballing into 100 reactions. Non-enzymatic antioxidants include vitamin C, vitamin E, plant polyphenols, carotenoids and glutathione (GSH).
Glutathione has been called the “master antioxidant” and is found in every single cell of your body, maximizing the activity of all the other antioxidants.
2. Enzymatic antioxidants work by breaking down and removing free radicals. In general, these antioxidant enzymes flush out dangerous oxidative products by converting them into hydrogen peroxide, then into water, in a multi-step process that requires a number of trace metal cofactors (copper, zinc, manganese and iron). You can’t supplement these enzymatic antioxidants orally – they must be produced in your body.
Most antioxidants found in foods and supplements are of the non-enzymatic type. They boost your enzymatic antioxidant defense.
The principle enzymatic antioxidants are the following:
• Superoxide dismutase (SOD): Assisted by copper, zinc, manganese and iron, SOD breaks down superoxide (which plays a major role in lipid peroxidation) into oxygen and hydrogen peroxide. SOD is present in nearly all aerobic cells and extracellular fluids.
• Catalase (CAT): Converts hydrogen peroxide into water and oxygen (using iron and manganese cofactors), hence finishing up the detoxification process that SOD started.
• Glutathione peroxidase (GSHpx) and glutathione reductase: These selenium-containing enzymes help break down hydrogen peroxide and organic peroxides into alcohols, and are particularly abundant in your liver.
As you can see, these powerful enzymes do a wonderful dance in your body that turns toxins into harmless water!
Water-Soluble and Lipid-Soluble Antioxidants
Another categorization of antioxidants is based on whether they are soluble in water (hydrophilic) or in lipids (hydrophobic). You require both types to protect your cells.
• The interior of your cells and the fluid between them are composed mainly of water.
• But your cell membranes are made largely of fat.
• As you know, oil and water don’t mix. Substances that are soluble in water are not soluble in fat, and vice versa.
• The lipid-soluble antioxidants (such as vitamins E and A, carotenoids, and lipoic acid) are primarily located in your cell membranes,
• Whereas the water-soluble antioxidants (such as vitamin C, polyphenols and glutathione) are present in aqueous fluids, such as your blood and the fluids within and around your cells (the cytosol, or cytoplasmic matrix).
• Free radicals can strike the watery cell contents or the fatty cellular membrane, so the cell needs defenses for BOTH.
• The lipid-soluble antioxidants are the ones that protect your cell membranes from lipid peroxidation.
The fact that antioxidants are so complex and multifactorial has led people to be confused about what antioxidants they should be taking. For example, I have been asked on more than one occasion if it’s necessary for example to take a resveratrol supplement if you are already taking astaxanthin.
The short answer is, YES.
Astaxanthin is a lipid-soluble antioxidant, and polyphenolic compounds such as resveratrol [especially abundant in grape skins and seeds, red wine, and purple grapejuice], are water-soluble antioxidants. As you have now seen, each type has its own special function.
But solubility isn’t the only variable among antioxidants.
Besides solubility and enzyme requirements, antioxidants also differ in terms of molecular size. There are small-molecule antioxidants and large-molecule protein antioxidants, which have different functions:
1. The primary function of the small molecule types is to mop up or “scavenge” the reactive oxygen species and carry them away through chemical neutralization. The main players in this category are vitamin C, vitamin E, lipoic acid, carotenoids, glutathione, and CoQ10.
2. The larger protein antioxidants tend to be the enzymes (SOD, CAT, O, H2O2, and GSHpx, outlined above), as well as “sacrificial proteins” that absorb ROS and prevent them from attacking your essential proteins. Albumin is an example of one of these sacrificial proteins, which “take the bullet” for crucial enzymes and DNA.
Clearly, biology has equipped you with a cornucopia of different defenses to cover just about every possible biological contingency.
A Myriad of Molecular Marvels
Besides interrupting free radical raids and melting down toxic invaders, antioxidants have some other unique and interesting functions, such as:
• Repairing Damaged Molecules: A few unique antioxidants can repair a damaged molecule by donating a hydrogen atom—and this becomes very important when the molecule is a critical one, like your DNA.
• Blocking Metal Radical Production (Chelating Effect): Toxic metals such as mercury and arsenic catalyze free radical production. Some antioxidants (such as green tea) have the ability to grab these metals and “hug” them so strongly that no chemical reaction can take place – and this is called chelation. Water-soluble chelating agents also help to escort toxic metals out of your body in your urine.
• Stimulating Gene Expression and Endogenous Antioxidant Production: Some substances have a remarkable ability to stimulate your body’s genes to increase your natural defenses. Whey proteins are thought to do this, as does exercise.
• “Shield Effect”: The flavonoids attach themselves to your DNA and protect it from attack by free radicals, acting as a virtual shield.
• Cancer Cell Suicide Promoter: Some antioxidants boost anti-cancer chemicals, halting cancer growth and even forcing some cancer cells to self destruct (apoptosis).
Exercise Can Help You Increase Your Own Antioxidants
In addition to your diet, exercise is an important part of boosting your body’s endogenous antioxidant production in a paradoxical way. Exercise is actually a potent oxidative stress, but by doing wise amounts of exercise, such as short amounts of high intensity exercises like Peak 8, it will help improve your body’s capacity to produce antioxidants.
Which Antioxidants Do You Need?
Let me emphasize that without question the most important way to optimize your antioxidant intake is to make sure you eat a large variety of locally grown fresh organic vegetables. Juicing is a convenient way to increase your intake, especially if you eat the pulp.
Additionally, reducing your sugar intake will decrease your antioxidant stress so that you will need less, and the ones that you have will work better and last longer. So resist sugars and processed foods.
You can also wisely select targeted nutrients to supplement your food choices.
I think Dr. Passwater says it best, so I will conclude with a passage from his book, The Antioxidants:
“Combinations of antioxidants are like a balanced symphony working together. A symphony orchestra produces sounds so much more harmonious than merely having 20 drums playing. It is not the quantity, but the blend. The same is true with antioxidant nutrients: you get better results with moderate amounts of a full complement than you get with using very large amounts of just one nutrient…
“For this reason, most of us in the field recommend that a person take a variety of antioxidants (a “cocktail”), not just a single substance.
“The importance of synergism is that the antioxidant nutrients each contribute to the total protection. They work together in the antioxidant cycle and reach all body compartments – fat and water-based, blood and internal cell. They protect against all types of free radicals and reactive oxygen species. No one antioxidant can do all of this.”
Personally my favorites are:
• Ubiquinol (Co-Q10)
– Joseph Mercola, MD
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Note: This information (© 1997-2012 Dr. Joseph Mercola. All Rights Reserved) has not been reviewed by the FDA. It is general information, based on the research and opinions of Dr. Mercola unless otherwise noted, and is not meant to prevent, diagnose, treat or cure any condition, illness, or disease. It is not intended to replace a one-on-one relationship with a qualified healthcare professional and is not intended as medical advice. It is always very important that you make no change in your healthcare plan or health support regimen without researching and discussing it in collaboration with your professional healthcare team.