Dr. Denham Harmon, M.D., Ph.D., first proposed a theory of aging as the indiscriminate chemical re-activity of free radicals possibly leading to random biological damage.
His idea has had much experimental success, and it is now considered a major theory of aging. Dr. Harmon's theory implies that antioxidants such as vitamin C and vitamin E, which prevent free radicals from oxidizing (removing electrons from) sensitive biological molecules, will slow the aging process.
Dr. Harmon launched his theory by showing, for the first time, that feeding a variety of antioxidants to mammals extended their life spans.
The the nucleus of an atom is surrounded by a cloud of electrons. These electrons surround the nucleus in pairs, but occasionally an atom loses an electron, leaving the atom with an "unpaired" electron. The atom is then called a "free radical", and it is very reactive. When cells in the body encounter a free radical, the reactive radical may cause destruction in the cell.
According to Dr. Harmon's free radical theory of aging, cells continuously produce free radicals, and constant free radical damage eventually kills the cell. When free radicals kill or damage enough cells in an organism, the organism ages.
"Free radical" is any atom or molecule which has an "unpaired electron" in the outer ring. An "unpaired electron" will also always mean that there is an odd number since "pairing" of electrons goes by 2s.
Protons have a positive electrical charge. Electrons have a negative electrical charge. The electrons move around the central mass made up of protons and neutrons. Neutrons have no electrical charge. The word is related to "neutral."
Let's take the example of helium, where the helium atom has 2 electrons circling around the center, and its center is made up of 2 protons and 2 neutrons. If 1 of those electrons "goes away", that electron would no longer have a mate! What we would have here is a free radical. It does have an odd number of electrons (1) in the outer ring (the only ring). We should note that it is very difficult to take one electron away from helium - that is why helium is considered so stable. Another word we need to understand in this situation is "ion." An "ion" is an atom with some "net electrical charge" - an atom with either a "+" charge or a "-" electrical charge.
Once an atom has fewer electrons, with a negative electrical charge, than protons, with a positive electrical charge, this atom now has more positive electrical charge than negative electrical charge - we therefore say that this atom is, itself, positively charged.
Because it is positively charged it attracts any available electron, with its negative charge. Opposites attract.
In summary, you should be comfortable with understanding what a "free radical" is. It is an atom with an unpaired electron in the outer ring. It is lacking an electron. Does a free radical always have to be just one atom? No. It can also be a molecule, made up of 2 or more atoms.
Free radicals are atoms or molecules which contain unpaired electrons. Since electrons have a very strong tendency to exist in a paired rather than an unpaired state, free radicals indiscriminately pick up electrons from other atoms, which in turn converts those other atoms into secondary free radicals, thus setting up a chain reaction which can cause substantial biological damage.
Dr. Denham Harmon, M.D., Ph.D., first proposed a theory of aging as the indiscriminate chemical re-activity of free radicals possibly leading to random biological damage. His idea has had much experimental success, and it is now considered a major theory of aging.
Dr. Harmon's theory implies that antioxidants such as vitamin C and vitamin E, which prevent free radicals from oxidizing (removing electrons from) sensitive biological molecules, will slow the aging process. Dr. Harmon launched his theory by showing, for the first time, that feeding a variety of antioxidants to mammals extended their life spans.
By what mechanisms do free radicals cause damage and disease?
Free radicals contribute to many different diseases. Chemically, a substance is oxidized when electrons are removed and reduced when electrons are added. All chemical reactions involve the transfer of electrons. The body generates energy by gradually oxidizing its food in a controlled manner and storing it in the form of chemical potential energy, called ATP.
Ironically, this energy-generation mechanism which is so essential to life can also set the stage for cell damage. The oxidation of foodstuffs is like a controlled fire which liberates energy but can also let sparks fly, giving rise to potential damage. The sparks in this analogy are free electrons escaping the transport system. These unpaired electrons readily form free radical molecules which are chemically reactive and highly unstable.
It is these free radical molecules which rapidly react with other molecules, setting off a chain reaction of free radical formation, somewhat similar to an atomic explosion.
So now we have this molecule which is missing an electron and is dying to get its hands on an electron to help fill its need. This free radical now goes and steals an electron from another molecule that is more willing to give one up and thus it becomes satisfied, but now the victim molecule has become a free radical! This goes on for quite some time. We therefore call this process the chain reaction of free radicals.
Cell membranes are made of unsaturated lipids. The unsaturated lipid molecules of cell membranes are particularly susceptible to this damaging free radicals process and readily contribute to the uncontrolled chain reaction.
Oxidative damage, another name for the chemical reaction that free radicals cause, can lead to a breakdown or even hardening of lipids, which makeup all cell walls. If the cell wall is hardened (lipid peroxidation) then it becomes impossible for the cell to properly get its nutrients, get signals from other cells to perform an action (such as firing of a neuron) and many other cellular activities can be affected. In addition to the cell walls, other biological molecules are also susceptible to damage, including RNA, DNA and protein enzymes.
The primary site of free radical damage is the DNA found in the mitochondria.
Mitochondria are small membrane-enclosed regions of a cell which produce the chemicals a cell uses for energy. Mitochondria are the "energy factory" of the cell. Every cell contains an enormous set of molecules called DNA which provide chemical instructions for a cell to function. This DNA is found in the nucleus of the cell, which serves as the "command center" of the cell, as well as in the mitochondria.
The cell automatically fixes much of the damage done to nuclear DNA. However, the DNA in the mitochondria cannot be readily fixed.
Therefore, extensive DNA damage accumulates over time and shuts down mitochondria, causing the cells to die and the organism to age.
Hence, this free radical generation process can disrupt all levels of cell function. This is why free radical damage is thought to be such a basic mechanism of tissue injury. It damages us at the cellular level.
The more toxic metals in your body, the higher the free radical activity.
Now here's the kicker. Heavy metals in your body multiply those free radicals chain reactions several thousands, possibly several million times. When a free radical molecule hits a metal atom in your body, the effect is multiplied many-fold. This is partly why it is so important to remove toxic metals from your body through chelation.
Free radicals are increased in activity and quantity by bumping into toxic metals in the body. Thus, toxic metals are a cause of free radicals.
Several hundred years ago we did NOT have the burden of toxic metals in our bodies that we now do, and we also did not have such an exposure to free radicals. If you remove the toxic metals from the body, you then greatly reduce the activity and the number of free radicals.
It is also clear that environmental agents initiate free radical problems. The toxicity of lead, pesticides, cadmium, ionizing radiation, alcohol and cigarette smoke may all be due to their free radical initiating ability.
Heart disease and free radicals:
Now let's talk about heart disease and free radicals. Heart disease is NOT caused by eating butter and eggs. The traditional view has been that when you ate butter and eggs and other foods high in cholesterol, you increase the amount of cholesterol in your blood stream. This is false. Dietary cholesterol does not increase blood cholesterol. Then, this excessive cholesterol would build up on the inner lining of the artery. Again, this is false. Next, the traditional view goes that cholesterol attracts particles of calcium floating along in the blood stream, building up a sort of sandwich of cholesterol - calcium - cholesterol - calcium - cholesterol. This is the traditional view.
It is safe to say that fewer and fewer researchers believe that high levels of fat or cholesterol in the diet are the primary cause of heart disease. An exception to this may be researchers who work for companies which offer high-priced cholesterol-lowering medications.
The actual cause of heart disease is damage done by free radicals to individual cells within the arteries. This free radical damage cannot be prevented or cured by any drugs - in fact most drugs are sources of MORE free radicals in the body.
Role of Antioxidants:
To combat the free radical chain propagation effect, the body uses antioxidants (chemical electron sinks) which quench the biochemical fire. The antioxidants include enzymes such as glutathione peroxidase, catalase and superoxide dismutase. Vitamin C, vitamin E, and A, beta carotene, coenzyme Q10.
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