� #1 �
Let's talk Antioxidants
I'm opening up a new topic for discussion here, that seems to be largely overlooked. Free radicals have been found to be the main cause of many of the ailments that plague us today. Most people have heard about free radicals and taking antioxidants to quench them, but don't have a thorough understanding of the subject. Not that I do, I'm learning more all the time. Even scientists aren't aware of all that is involved with this connundrum of oxidation. So lets hash this out, little by little and see if we can get a good working understanding of OXIDATION. I'm not going to throw all the data I have out here all at once, that would be futile, as nobody is going to sit for hours reading it all, and worse, trying to digest it. So I'm starting this thread with some basics of what oxidation is all about, and from there we can start hashing it out. Here goes:
The role of oxidative stress is well recognized now in numerous pathological states, where antioxidants can play very important role. Recent studies provide evidences that low levels of antioxidants are associated with increased risk for many pathological states and that increased intake appears to be protective. However, there are conflicting studies also, that question the rationale for antioxidant supplementation in these conditions by suggesting detrimental effects to the health. Suicidal oxidative stress produced by some of the antioxidants under certain circumstances remains the major cause of concern ,as many antioxidants can act as pro-oxidants in certain conditions.
Moreover, at present there are number of unanswered questions associated with practical application of antioxidant therapy like appropriate timing of administration, dose & duration of therapy, which still need to be determined. Inspite of these concerns, antioxidant therapy has gained an important status presently in the prevention and treatment of various pathological conditions. However, under the shadow of these concerns, the supplementation of natural dietary antioxidant resources seems to be a safe and effective approach currently.
The free radical can be defined as a chemical species, an atom or a molecule that has one or more unpaired electrons in its valance shell and is capable of existing independently. As free radical contains an odd number of electrons which makes it unstable, short lived and highly reactive, therefore it can react quickly with other compounds in order to capture the needed electron to gain stability. Generally, free radical attacks the nearest stable molecule �stealing� its electron. When the attacked molecule looses its electron, it becomes a free radical itself, beginning a chain reaction cascade resulting in disruption of a living cell1,2.
Most common radical derivatives of oxygen like superoxide free radical anion (O2�‑), hydroxyl free radical (OH�), lipid peroxyl (LO�), lipid alkoxyl (LOO�) and lipid peroxide (LOOH) as well as non-radical derivatives such as hydrogen peroxide (H2O2) and singlet oxygen (1O2) are collectively known as reactive oxygen species (ROS)2. These free radicals/reactive oxygen species are produced mainly from two important sources1,2 in the biological system i.e. cellular metabolism and environmental sources.
Table-I: SOURCES OF THE REACTIVE OXYGEN SPECIES IN BIOLOGICAL SYESTM 1 , 2
Cellular Metabolism � Mitochondrial electron transport
� Endoplasmic reticulum oxidation
� Enzymatic activity like :
NADPH oxidase, Xanthine oxidase, Monoamine oxidase, Tyrosine hydroxylase, L-amino oxidase, Diamine oxidase, Glycolate oxidase, α-hydroxy acid oxidase, L �gluconolactone oxidase.
� Prostaglandin synthesis.
� Autooxidation of adrenaline, Thiol, Ascorbic acid
� Reduced riboflavin, FMNH2 FADH2
� Nitric oxide sythatase
� Stimulated neutrophils
� Activated phagocytic cells
� Reperfusion injury.
� Cytochrome P450.
� Drugs: Halothene, Paracetamol, Bleomycine, Doxorubicin, Metrenidazole, Ethanol.
�Transition Metals (Cu, Fe)
� X-ray by water radiolysis
� Light by photoionization
� High Temperature
Free radical and reactive oxygen species production in the animal cell is inevitable.
Normally, there is an equilibrium between a free radical/reactive oxygen species formation and endogenous antioxidant defense mechanisms, but if this balance is disturbed, it can produce oxidative stress2, 3. This state of oxidative stress can result in injury to all the important cellular components like proteins, DNA and membrane lipids which can cause cell death.
In recent years increasing experimental and clinical data has provided compelling evidences for the involvement of FR/ROS in large number of pathophysiological states1,2,4.
This has led to increasing curiosity and interest among the scientists and researchers globally to evaluate potential benefits from antioxidant therapy. Presently studies provide evidences that low levels of antioxidants are associated with increased risk for many pathological states and that increased in take appears to be protective5-11.
However, there are conflicting reports also which question the rationale for antioxidant supplementation by suggesting them to be ineffective12-20 or in some cases detrimental21,22 to the health. Moreover, there are few concerns and some unsolved questions, which still remain to be determined in the practical application of antioxidant therapy. Therefore, an attempt to understand, the mechanism of antioxidants and their past and present status is made in the present article.
More to follow....
� #3 �
Iggy, recently, we have been hearing that Vit C in large doses ( I don't know what dose is large) are potentially harmful, due to it's pro-oxidant action. What can you add to that, please.
� #5 �
But I would consider that to be a large dose. Is this to bowel tolerance?
I had thought that a moderate dose wuld be 500 mgm - 1000 mgm.
Why is that wrong?
� #6 �
Oxidation is life, so free radicals, in the proper place (mitochondria, for instance) is life. The problem is free radicals in the wrong place.
A lot of sources of harmful free radicals are given, but not everyone is exposed uniformly to many of them (pollution, cigarettes, etc.). I think the most important source, which can be common to everyone, is virtually overlooked: blood glucose.
I'm sounding like a broken record now, having repeated this so often:
Glucose is a very strong reducing (chemically speaking) sugar, leaving a lot of free radicals in its wake. But we all know that it's also essential for life. So its levels in the blood must be strictly regulated (that's why I see insulin as an emergency hormone, not something that has to be secreted after every (wrong) meal).
Now, it's virtually expected that insulin is secreted after every meal. It does not have to be that way. In fact, I believe it should not be that way. We could either eat properly so that our blood glucose levels don't spike, or we could constantly engage in physical activity in between meals -- contracting muscles absorbs glucose from the blood without the need for insulin.
Notice where we find the powerful blood antioxidants, vitamin E forms and tocotrienol (not to mention the B-vitamins as well): in rice and wheat! Our creator knew that eating these and their products will increase our need for those antioxidants. Unfortunately, these are removed from food products and we eat only the starch -- thus raising our blood glucose levels, causing high levels of free radicals, but lacking the antioxidants.
Keeping blood glucose levels in control will really drop our need for antioxidants. (It would also keep us lean, and control LDL levels.)
� #7 �
Great insights Gerry,
I think your theory on glucose probably hits the nail on the head quite acurately. I know that glucose reduces proteins, causing glycated proteins, which are very destructive. I never quite thought about the insulin-need aspect of it before. But it makes perfect sense. If we were to eat a good amount of starch, we shouldn't need insulin if we are active enough. Our muscles and brains burn glucose for energy, and if kept active, could burn the glucose, whereby little insulin would be needed for getting it into the cells.
We have become very sedentary in our lives. Our forebearers worked hard all day everyday like slaves, just to survive. But with all our modern conveniences and techology, we don't hardly have to lift a finger to survive.
According to your theory, good whole foods should provide all the antioxidants we need to quench the free radicals that are created from metabolizing that food. And if you look at the actual amounts of antioxidants in whole foods, it is quite small. This is where I had trouble trying to decipher what our actual needs for these nutrients are in previous discussions. Most believe that 7 IU's of vitamin E is nowhere near enough to protect us, and that we need a minium of 100 to 400 IU's per day.
If we look at it from your standpoint, that food supplies all the antioxidants we need, the belief that we need such high amounts becomes ludicrous, because we would have to consume a semi-truck load of food to get those amounts. That is not how we were intended to eat.
Then on the other hand, we have the fact that, some antioxidants themselves ARE FREE RADICALS. I think this is a big part of what everyone is missing with this subject. By now most people are aware that we are bombarded by excessive free radicals (beyond the vital oxidation processes) in every aspect of our lives. And they have all read somewhere, that vitamins E and C, and various other nutrients are ANTIOXIDANTS, that will quench the free radicals. But what hasn't been explained to them, is that antioxidants themselves can be free radicals, and that taking large amounts of them only increases their burden. Note the following from above:
� #9 �
WOW, Iggy. If most of us took that much Vit C we would be in the bathroom all day.
This thing about oxidation really has me stumped.
Next week I will be going to a seminar on Ozone therapy. Ozone is 03. When it gets inside your body is oxidizes a lot of stuff when it looses that extra oxygen molecule. Ozone clinics have been popular in parts of Europe for some time. I hear that there are about 7,000 of them. The reported benefits are astounding, curing lots of hard to cure infections including AIDS, some cancers, a wide variety of skin diseases.
So from this thread I will take some of these questions about free radicals and oxidation.
I suspect that that oxygen may be the safest free radical in the form of a singlet oxygen that anyone can use.
� #11 �
bifrost99, did you once post an article about vitamin C, Inuits not needing to eat viatmin C because they ate little carbohydrates, scurvy? If you didn't, I could look for it. It could get some great posts going if we have new people that haven't read it.
� #12 �
Considering all of the continuing talk about oxidants and antioxidants, please allow me to take off on a tangent:
Doesn't it usually come down to an excess or a shortage of electrons being at the right place at the right time?
And, if that is true, consider what happens when you employ a practice called 'zilling' while using the very inexpensive 'Godzilla' device.
This process can flood any tissue region with 1 followed by many, many zeros of electrons each and every second. Now, admittedly, there is no net change in the number of electrons within a region between electrodes; they enter at the negative electrode and are removed at the positive electrode. But it may well be that the region between the electrodes is simply being normalized.
I believe that there is a lot more to be learned in this practice. I continue to practice and watch for new info.
Imagined knowledge kills learning . . .
The cure for boredom is curiosity...there is no cure for curiosity..
� #13 �
Ralph Moss prepared a report on this controversy. I'm thinking I'll just buy it so we can all parse it here.
As cancer is expected to affect 1 of 2 men and 1 of 3 women (American) in their lifetime, I believe in doing research ahead of a (God forbid) diagnosis.
Moss gives this reason for writing the report:
� #15 �
Re: vitamin C
Stefansson did not understand why certain people who never had vitamin C in their diets did not get scurvy. Or even why an expedition with vitamin C in its stores still suffered and died from scurvy.
We now know that vitamin C is needed to convert lysine and proline to hydroxylysine and hydroxyproline, which are essential components of connective tissue.
Thus, if we are already getting the hydroxylysine and hydroxyproline in our diets (as in meat or fish based diets of the Eskimos), then we don't need vitamin C at all.
On the other hand, no matter how much vitamin C we get, if we don't have lysine and proline, then we can still come down with scurvy, as in the expedition he cited.
So while vitamin C is an antioxidant, its important function is hydroxylation of these amino acids. It would probably be involved in hydroxylation of phenylalanine to tyrosine to adrenalin, which is probably why the most concentrated place of vitamin C in our bodies is in our adrenal glands.
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