Dr. Mercola
May 16, 2011
http://articles.mercola.com/sites/articles/archive/2011/05/16/all-about-antioxidants.aspx
http://www.youtube.com/watch?v=T_Xo5AaTH8U&feature=player_embedded
http://www.youtube.com/watch?v=T_Xo5AaTH8U&feature=player_embedded
1) Fun portrayal by Food Network star Alton Brown about how greedy free radicals run around, desperately stealing electrons from other molecules.
2) Overview of free radicals, antioxidants, and oxidative stress, promoting acai berry
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, Ph.D. 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.
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 biogerontologist 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, as illustrated in the video above.
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:
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.
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.
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.
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.
Antioxidants can be categorized into two types:
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.
Most antioxidants found in foods and supplements are of the non-enzymatic type. They boost your enzymatic antioxidant defense system by doing a "first sweep," disarming the free radicals, which helps prevent depletion of your enzymatic antioxidants.
The principle enzymatic antioxidants are the following:
As you can see, these powerful enzymes do a wonderful dance in your body that turns toxins into harmless water!
Another categorization of antioxidantsis 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 to take Purple Defense if you are already taking astaxanthin.
The short answer is, YES.
Astaxanthin is a lipid-soluble antioxidant, and the antioxidants found in Purple Defense (anthocyanins, polyphenols, resveratrol) 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:
Clearly, biology has equipped you with a cornucopia of different defenses to cover just about every possible biological contingency.
Besides interrupting free radical raids and melting down toxic invaders, antioxidants have some other unique and interesting functions, such as:
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.
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 for 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