Vitamin
C Therapy In Cardiovascular Disease
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| Before You Begin
Information presented here is for general
educational purposes only. Each one of us is biochemically and metabolically
different. If you have a specific health concern and wish my personalized
nutritional recommendation, write to me by clicking
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The
past 30 years saw more and more people opting for the use of mega-dose Vitamin
C therapy together with lysine, proline, and carnitine to prevent and treat
heart diseases. Although this therapy is still not within mainstream medicine,
many well-conducted studies have proven the effectiveness of these natural compounds.
We will be dwelling on this subject in greater detail below. Meanwhile, let
us first have a basic understanding of the functions of the endothelial and
how atherosclerosis, the foundation of cardiovascular disease comes about.
ENDOTHELIUM
We all know that atherosclerosis is the main cause for heart attack and strokes.
Atherosclerosis is the result of injury to the extremely thin layer of endothelial
cells that line the inside surface (the lumina) of the heart and blood vessel
walls. Circulatory toxins such as smoke,
free radicals, sugar and infection cause these injuries. Numerous
established studies have confirmed that an impaired endothelial function is
linked to all major coronary heart diseases.
Although the endothelium is extremely thin, it is a highly complex structure
in terms of function. It regulates the structural integrity of the vascular
wall by secreting numerous factors that determine not only the contractility
of the walls but also the homeostasis of the blood. Imbalance of this contractility
function will lead to hypertension. If the local vascular homeostasis is
disturbed, it will result in platelet deposition, aggregation and a release
of factors that promote smooth muscle proliferation. When this happens, you
may get fibrosis, atherosclerosis and thrombus formation. As imbalances
are first initiated at the endothelial, where insults excite an inflammatory
response, the endothelium is therefore the first link between inflammation
and coagulation. The endothelium also represents a surface where proteins
are involved in coagulating. It is also here that the development of inflammation
are expressed
We will now look at the cascade of events a little closer. A high sugar diet
and an environment full of cigarette smoke produce toxins such as free radicals
that are ever ready to attack the endothelium. The endothelium, in an attempt
to heal itself will launch an inflammatory response to get rid of the unwanted
guests.
The characteristics of an inflammatory response are as follows:
1. Vasodilatation to increase blood flow to the area.
2. Increase vascular permeability to allow diffusible components to enter the
site.
3. Cellular infiltration by chemotaxis, or the directed movement of inflammatory
cells through the walls of blood vessels to the site of injury.
4. Changes in biosysnthetic, metabolic, and catabolic profiles of many organs.
5. Activation of cells of the immune system as well as of complex enzymatic
systems of blood plasma.
During an inflammatory response, our blood flow is increased to transport more
white blood cells to the injured area. The white blood cells first surround
the damaged tissue, then together with the other cells in the damaged tissues
neutralize, repair the damage and remove whatever is causing the injury. This
reaction can be measured in the blood by the
elevation of a substance called C reactive protein.
Meanwhile, a small amount of LDL ("Bad")
cholesterol that has built up in the artery wall becomes oxidized. Oxidized
LDL is one of the triggers that set off a chain reaction. It causes the endothelium
to express a special kind of molecule "glue" called ELAMS (endothelial-leukcyte
adhesion molecules). These molecules, which happen to be floating by in the
bloodstream causes certain kinds of white blood cells (monocytes and T lymphocytes)
to stick to the endothelium. At this point in time, the inflammatory response
is still well under control and normal, whether it is in the artery or in the
tissue.
Beyond this point, the healing process goes off track. The white blood
cells will start to move between and below the endothelium and cause damage
in two major ways. Firstly, they will cause some of the muscles cells in the
artery walls to grow and secondly, they incorporate particles into the artery
wall, consuming the oxidized LDL particles. What results from here is a fatty
streak that becomes a fibrous plaque.
This intricate process begins in the tissue under the endothelium. Due to
inflammatory reactions, the endothelium's structure becomes permeable to lipoproteins,
particularly low-density lipoproteins (LDL) and macrophages. These particles
will enter into the site of injury, accumulate cholesterol as cholesterylester
and develop into foam cells. A raised LDL-cholesterol and related cholesterol
carrier called lipoprotein (a) concentration is recognized by many as a major
risk factor for heart disease as it appears to be the donor of cholesterol deposited
in the artherosclerotic plaque. Being adhesive, the cells will attract other
substances, resulting in a continuous deposition of unwanted conglomerate which
we called fatty streak. The latter consist of lipids (fats), complex carbohydrates,
blood, blood products, fibrous tissue, oxidized ascorbates and calcium deposits.
As the fatty streak becomes bigger and bigger, this resulting fibrosis forms
an " endothelial tumor" or a plaque. The process of plaque formation
is called atherosclerosis. Atherosclerosis blocks the blood's pathway and narrows
the arteries over time.
The arteries in our bodies consist of three layers:
1 The intima is composed of the endothelium and underlying sub-intimal connective
tissues.
2 The media is composed of the internal and external elastic lamina surrounding
the smooth muscles.
3 The adventitia lies at the outer most area comprising of connective tissues
in which nerve fibers are dispersed.
Therefore, the hallmarks of an artherosclerotic
vessel are intimal hyalinization, medial hypertrophy, and endothelial hyperplasia.
Histologically speaking, lipids accumulate in the endothelium and muscle cells.
In severe cases, lipid particles appear extracellulary in the intima.
It is very interestingly to note that artherosclerotic
plaque contains both oxidized lipids and relatively large amounts of alpha-tocopherol
and ascobate. During various studies, researchers have discovered
that plaque samples which contained more ascorbate and urate than normal arteries
have no discernible differences in the Vitamin C redox status between plaque
and control materials. The most abundant of all studied lipids in plaque samples
was free cholesterol, followed by cholesteryl oleate and cholesteryl linoleate.
The study also noted that approximately 30% of the plaque was oxidized.
If we want to prevent or slow down the accumulation
of cholesterol due to the modification or oxidation of LDL, we can take Vitamin
C. Various types of heart cells, including endothelial cells, can
oxidize the low-density lipoprotein (LDL) form of cholesterol and promote heart
disease. As such, taking Vitamin C will help
to enrich the endothelial cells and make them less likely to oxidize LDL.
CLINICAL
STUDIES
The therapeutic use of high and mega-dose Vitamin C to reduce atherosclerosis
is validated in many well-conducted clinical trials.
1.
Vitamin C Intake Neutralizes A High Fat Meal.
In a study conducted by Dr. Plotnick, University of Maryland School of Medicine,
20 healthy men and women were fed on one of the three breakfasts: -
(1) A high-fat meal consisting of an Egg McMuffin, Sausage McMuffin, and two
hash brown patties.
(2) A high-fat breakfast after the subjects were given 1,000 mg of Vitamin C
and 800 IU of vitamin E.
(3) A low-fat breakfast of cereal, skim milk, and orange juice.
In this study, Dr Plotnick discovered that a
single high-fat meal increased blood triglyceride levels by more than 60 percent
and decreased endothelial function by two to four hours. The decrease
in endothelial function also correlated with an increase in triglyceride levels,
but not with fasting triglyceride levels. The researchers were also pleased
to note that taking Vitamins C and E just
before the high-fat meal helped to maintain normal endothelial functions.
Surprisingly, the effects of the vitamin
were the same as eating the low-fat meal, which produced no increase in triglycerides
or decrease in endothelial function.
2.
Vitamin C Helps to Normalize Blood Flow
In order to determine the effects of Vitamin C on normalizing blood flow, researchers
measured the thickness of the intima in the carotid arteries of 231 people with
atherosclerosis and an equal number of healthy people. The intima is the innermost
layer of the blood vessel walls and a thickened intima is a sign of cardiovascular
disease. High blood levels of carotenoids, particularly lutein and zeaxanthin
are related to normal intima thickness. During an animal study conducted using
rabbits, it was reported that the rabbit's blood flow decreased and red blood
cells clumped together in small blood vessels after being fed a high-cholesterol
diet. However, when these rabbits were given
supplemental Vitamin C, their blood flow returned to normal.
3.
Vitamin C Protects Vascular Wall
Vitamin
C is very effective for patients with congestive heart failure (CHF). It prevents
endothelial cell apoptosis.
In a series of experiments, Dr. Stefanie Dimmeler, University of Frankfurt
first showed that tumor necrosis factor-alpha (TNF-alpha) increased apoptosis
in cultured endothelial cells by 3 times. However, when Vitamin C was added
to the cultures, this apoptosis was remarkably decreased. Similar results
were also seen in cells treated with angiotensin II.
Researchers explained then Vitamin C interfered with apoptosis signaling by
inhibiting the ability of TNF-alpha to induce cytochrome C released from the
mitochondria. This suppressed the activation of caspase-9.
In an investigation, 34 patients were given Vitamin C or placebo. At first,
they were given 2.5 g of Vitamin C or sodium chloride 0.9% intravenously for
10 minutes. This was followed by 2 g of Vitamin C or placebo given orally
twice a day for a period of 3 days.
The results reported that after taking Vitamin C, plasma levels of circulating
apoptotic microparticles were reduced to 32% of baseline levels. Patients
treated with placebo were reduced by an insignificant amount to 87% of baseline
levels.
When cultured endothelial cells were exposed to the patient's serum, apoptosis
was significantly reduced from the patients treated with Vitamin C compared
with the subjects treated with placebo.
The researchers also noted that Vitamin C did not affect serum concentrations
of TNF-alpha or other circulating cytokines. As such, the altered serum levels
of circulating cytokines do not contribute to the protective effects of Vitamin
C on endothelial cell apoptosis in CHF patients.
4.
Vitamin C Helps to Neutralize Cigarette Smoke
Cigarette smoking causes endothelial dysfunction.
A study using 20 smokers and non-smokers was conducted to examine the effects
of Vitamin C and cigarette smoking on endothelium-dependent vasodilation.
The lumen diameter and the velocity flow of the brachial arteries at rest
were measured during:
1. The reactive hyperemia following transient arterial occlusion
2. After 0.3 mg of sublingal nitroglycerin with high-resolution ultrasound.
3. After infusion of saline or saline plus Vitamin C (10 mg/min for 20 min).
The same study was also performed in 15 smokers before and 10 minutes after
cigarette smoking. Their serum levels of Vitamin C and plasma levels of thiobarbituric
acid reactive substances (TBARS) as an index of lipid peroxidation were also
measured. The results showed that the smokers had lower Vitamin C levels and
higher TBARS levels. Their results also showed the impairment of flow-dependent
vasodilatation when compared with non-smokers. When Vitamin C was given,
it improved the impairment of flow -dependent vasodilatation and decreased
TBARS in smokers. However, Vitamin C administration did not have any effects
in the non-smokers. The researchers also concluded that cigarette smoking
acutely worsened the impairment of flow-dependent vasodilatation and increased
TBARS. As such, researchers conclude that:
(1) Endothelium-dependent vasodilatation in the brachial arteries was impaired
in smokers. When Vitamin C was given, there was a decrease in TBARS.
(2) Cigarette smoking produced acute impairment of endothelium-dependent vasodilatation
in smokers in association with an increase in TBARS.
5.
Vitamin C Reduces Blood Pressure
The
endothelium regulates the vascular tone by releasing relaxing eicosanoids
such as prostacyclin (PGI2) or contracting eicosanoids such as TXA2 in a delicate
balance to maintain normal blood pressure. A dysfunctional endothelium
caused by free radicals can offset this balance. The net equilibrium is then
pushed towards an increase in TXA2/PGI2 favoring vasoconstriction and hypertension.
This vasoconstriction leads to peripheral neuropathy as vascular supply is
reduced.
A study was conducted with a sampling group of 50 hypertensive patients. 25
of these patients were given 500 milligrams a day of Vitamin C, the rest were
given matching placebo (inert pills). Before the study began, their average
blood pressure was taken as 155/88 mmHg. Subsequently, it was again measured
two hours after giving the first dose, and after one month of treatment. The
study was double blind, so that no one knew what type of pills each patient
was getting until after the study. The results showed no effects on the subject's
blood pressure two hours after the first dose. However, after one month, the
systolic pressure in the Vitamin C group fell by 12 mm Hg, which is much more
than those in the placebo group. The effects on diastolic pressure were less
pronounced, and did not reach any statistical significance.
In this study, the effects on systolic pressure were quite strong. One reason
as to why the change in diastolic pressure was less pronounced may have been
because it was normal to begin with.
Other studies on the effects of Vitamin C on blood pressure were also conducted
but the results were less consistent.
6.
Vitamin C Protects Endothelial Oxidation
Vitamin C protects endothelial function by stopping LDL oxidation, platelet
aggregation, and leukocyte adhesion to the endothelium.
A study was conducted on a group of healthy men to see if low plasma antioxidant
levels increased ox-LDL (oxidized low density lipid) levels. Ox-LDL is associated
with oxidative damages to cells. The result showed that low plasma tocopherol
levels were significantly associated with increased ox-LDL levels. Additionally,
smoking raises ox-LDL levels further. The study concluded that alpha-tocopherol
protected against oxidative cell damages. Supplementing with Vitamin C would
help to decrease this damage, especially in smokers.
Vitamin E when combined with Vitamin C was proven in many studies to reduce
apoptosis (cell death) and oxidative damages to healthy heart muscles and
endothelial cells. During a study conducted on AMI (acute myocardial infarction)
patients, it was reported that when these patients were given supplements
of Vitamin E and C, the production of free radicals in leukocytes was decreased.
7.
Vitamin C Helps Heart Failure
Vitamin C can help heart patients by improving the functions of their blood
vessels.
When our heart is unable to pump efficiently enough to meet our body's needs,
we will develop congestive heart failure. The signs and symptoms are fatigue
and the shortness of breath. Most heart failures are usually a direct result
from an underlying heart condition such as coronary artery disease.
German and French researchers have discovered that Vitamin C helps to prevent
the cells in the blood vessel wall from dying. In order words, Vitamin C benefits
those people with congestive heart failure, who have poor function in the
blood vessel walls.
The damaging form of oxygen in the body is called reactive oxygen that is
accumulated in the blood as the condition progresses. This oxidative stress
contributes to dysfunction in the endothelium by damaging its cells. As Vitamin
C is a potent antioxidant, it helps to remove these cell-damaging oxygen compounds
from the body.
During an experiment, investigators gave 34 patients either Vitamin C treatment
or an inactive placebo. The Vitamin C patients were first given an intravenous
dose of Vitamin C, followed by 3 days of oral supplements. They were all were
V on standard drug treatment for heart failure. Prior to treating these patients,
the researchers already had first hand knowledge that exposing endothelial
cells to Vitamin C kept inflammatory proteins from apoptosis, a form of cell
self-destruction. As such, when the blood samples from the patients were tested,
they found that those who received Vitamin C showed less evidence of apoptosis
in their endothelial cells. The placebo patients did not show any changes.
8.
Vitamin C Prevents Diabetes
Dr. Farris K. Timimi and his team at the Brigham and Women's Hospital and
Harvard Medical School, Boston, Massachusetts, found that the short-term
infusion of Vitamin C improved blood vessel functions in 10 of the patients
with diabetes, but not in the other 10 patients who were non-diabetics.
During the course of study, this team also examined the functions of the endothelium
and the layer of cells that lines the insides of blood vessels, which helps
them to dilate and contract. They also concluded that Vitamin C helps to
destroy free radicals present in the endothelium. These oxygen-derived
free radicals are harmful molecules accumulated in the body as one age.
Infusions of methacholine chloride, a substance that makes blood vessels dilate
was given to the patients before and after intravenous Vitamin C administrations.
Subsequently, the researchers measured the patient's blood flow in the forearms.
Within the diabetic groups, Vitamin C increased the ability of the endothelium
to help relax the blood vessels.
In the Journal of the American College of Cardiology, Timimi's
team concluded, "This result supports the notion that oxygen-derived
free radicals may contribute to abnormal vascular function in patients with
diabetes mellitus." The investigators also noted that
the blood levels of Vitamin C would be difficult to achieve with over-the-counter
supplements.
9.
Vitamin C helps hypercholesterolemia
Whether Vitamin C can help people with hypercholesterolemia has yielded
mixed results. Most studies are carried out
using Vitamin C only and in dosages of below 500 mg. The lack of consistently
positive results may be attributed to the relatively small doses and therefore
insufficient intracellular concentrations
VITAMIN
C AND COLLAGEN
In addition to the well-established anti-oxidative effects of Vitamin C on
the endothelium wall, Vitamin C has yet another important function. Vitamin
C helps in the formation of critical collagens responsible for keeping the
vascular system pliable and healthy. In the blood vessels, collagen,
together with elastic fibers, form an integral part of the sub-endothelial
connective tissue just below the endothelium (a single layer of very thin
squamous epithelial cell that lines all blood vessels), as well as the external
elastic lamina.
WHAT
IS COLLAGEN?
Collagen is the most abundant protein in the human body. Most proteins
such as enzymes and co-factors occur in small amount but there are a few exceptions,
notably hemoglobin (in red blood cells) and collagen that exists in abundance
throughout the body.
Collagen is omnipresent in our body. It forms the foundational matrix of
our skin, bones, teeth, blood vessels, eyes, heart, and essentially the whole
body. Collagen is stronger than a steel wire of the same weight. When
it is combined with elastin and macropolysaccharides, a connective tissue
network forms. It is this network that holds our body together. Collagen is
so important in our bodies that without it, our body will not function. Of
all the non-mineral constituents of the mammalian body, collegen forms a large
proportion next to water and fats.
Like other proteins, collagen consists of a long chain of amino-acid call
peptides. One molecule of collagen contains about 1000 amino-acids and 16,000
atoms.
Collagen comprises two important amino acids. They are glycine and hydroxyproline.
The polypeptide chain of these two amino acids forms a helix structure. Three
of these helical strands form a complete molecule. It actually resembles the
components of a rope when coiled together.
HOW
COLLAGEN IS MADE
Collagen is a complex molecule, the production of which occurs in several
stages. The amino acids glycine and proline are the two key components.
When they are exposed to Vitamin C, they form a compound called pro-collagen.
The exact mechanism is not known, but studies have shown that prolonged
exposure of human connective tissue culture to Vitamin C results in an eight-fold
increase in the synthesis of collagen and not other proteins. The
pro-collagen, a precursor to collagen is then converted into collagen in a
reaction that substitutes a hydroxyl group, OH, for a hydrogen atom, H, in
the proline and lyine point of the polypeptide pro-collagen chain. When Vitamin
C is added, this hydroxylation process is catalysed by 2 different enzymes
called prolyl-4-hydoxylase and lysyl-hydroxylase. As such, Vitamin C functions
as a catalyst. It has been shown by researcher Myllyla and his team that during
this reaction, one molecule of Vitamin C is destroyed for each H replaced
by OH. In other words, one molecule of Vitamin
C is actually given up.
The main building blocks of collagen are
glycine, proline, lysine and Vitamin C, out of which only proline can
be manufactured by the body from glutamine.
It is actually interesting to note that
prisoners who have suffered Vitamin C deficiency have wide spread fatty deposits
in their arteries.
THE
THREE MUSKETEERS - Vitamin C, LYSINE, AND PROLINE
Vitamin C is vital as a catalyst during collagen production. Vitamin
C's destruction so as to allow the formation of collagen molecule is another
reason why Vitamin C depletion is an on-going process. When a person
ages, the wear and tear of collagen will occur. Collagen
will therefore have to be continually synthesized to keep the body going at
optimum health.
Lysine also plays an important role in collagen synthesis. In addition,
Lysine has a strong attraction for a sub-fraction of cholesterol call lipoprotein(a),
commonly known as Lp(a). Lp(a) is manufactured by the liver during the
cholesterol synthesis process. It is a sticky substance that adheres to the
endothelium (innermost layer) of the vascular wall, resulting in plaque formation
and attracting other fatty deposits such as LDL cholesterol, calcium and fibrinogen
to form a plaque. Lp(a) is an independent
risk factor for cardiovascular disease. It is a more sensitive and earlier
indicator of atherosclerosis than total or LDL cholesterol.
Lysine has a strong affinity for Lp(a).
As such, if we were to flood our bodies
with lysine, our bodies will be cleared of this sticky substance and reduce
our chances of having heart diseases.
The third non-essential amino acid is proline.
It is also a main component of collagen. When our bodies lack Vitamin C,
it causes proline to be lost in the urine as there is a net loss of collagen
building in the body. Like lysine, proline
has a high affinity for Lp(a) and therefore able to dissolve plaque.
It is said to be even stronger than lysine in this action. It not only prevents
further build-up of artherosclerotic deposits, it also helps to release already
deposited fat globules from the blood vessel walls into the blood stream.
In a nutshell, the compounds, lysine and
proline, Vitamin C, CoQ10, Vitamin E and Vitamin A prevent artherosclerotic
plaque from forming in the blood vessels. It is also important to note that
mega-doses of Vitamin C, proline and lysine are necessary to achieve this
effect.
DOSAGE
OF Vitamin C, LYSINE AND PROLINE
As mentioned above, mega-dose of Vitamin
C (1-10 grams), lysine (1-5 grams), and proline (1-2 grams) are necessary
to prevent and cure atherosclerosis and lowering of key cardiovascular markers
such as lipoprotein(a).
Well known scientist, Dr Linus Pauling, towards the end of his life at age
94 took about 18 grams of Vitamin C a day. While the RDA is only 80 mg a day
for healthy individuals, cancer patients routinely take about 10 to 30 grams
daily.
Mega-dose Vitamin C has very little side effects. The most common occurrence
is diarrhea and this is a physiological response that reflects tissue
saturation and the body's natural way of removing excessive Vitamin C. The
amount of Vitamin C intake that leads to diarrhea is called the Bowel Tolerance
Level (BTL). This side effect is usually harmless. When
we get diarrhea, we just simply reduce our dosage once the BTL is reached.
Sometimes, mineral ascobates are preferred in mega-dosing as they are
less irritating to the gastric mucosa. Bioflavanoids are also added to synergistically
improve the oxidation effects of Vitamin C. As Vitamin C is water-soluble
and is secreted out from the body relatively quickly, we should spread
the intake regiment throughout the day.
We can also consider the fat-soluble form
of Vitamin C called ascobyl palmitate. The latter remains in the
body longer than water-soluble ascorbic acid as it is fat-soluble and can
penetrates into the tissues that the former is unable to do so.
| Attention
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the use of nutritionals should therefore be personalized for your
body. One person’s nutrient can be another person’s toxin. If you
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EXPENSIVE
URINE?
Dr.
Mark Levine, National Institutes of Health have raised an interesting fact.
He said that a daily intake of 200 mg of Vitamin C is enough to saturate tissue
Vitamin C levels. If this amount is exceeded, the extra Vitamin C will be
excreted via the urine. As such, Dr Levine
believes that healthy young people may not benefit from Vitamin C intakes
of more than 200 mg/day.
However, some of us who are ill may need
vitamin C at higher doses. For example, pregnant women, smokers,
the elderly and those with different disease conditions will definitely require
higher doses. Another group of people who will need mega doses are those
with inflammatory conditions, such as rheumatoid arthritis and inflammatory
bowel disease. This is due to the reason that inflammatory cells, when
activated generate a lot of free radicals, which depletes Vitamin C levels.
Our bodies will then need to replace it with much more Vitamin C. More Vitamin
C in white blood cells is also needed when the immune system is responding
to bacterial or viral attack, or when a person suffers from arthritis or diabetes.
The exact amount of vitamin C under certain disease conditions or in different
patient groups is still not quite clear. However, we do know that
animals who are capable of making Vitamin C under stress puts out 4 to 10
times more Vitamin C than they normally produce.
If we know the readings of our blood levels, we should base our Vitamin C
intake on the actual measurement of Vitamin C in the plasma, as this will
take into consideration inter-individual differences as well as other conditions
associated with decreased absorption or increased utilization of Vitamin C.
Some people may require much larger doses of Vitamin C as their absorption
of Vitamin C is poor. Others may use it up at very high rates for unknown
reasons. However, this should be reflected in a decreased plasma Vitamin
C level and be corrected by the intake of Vitamin C so that the plasma levels
are increased into a range associated with tissue saturation and decreased
risk for disease.
The dosages of Vitamin C vary amongst individuals.
Some people only require 5 grams of Vitamin C to overcome a flu, while others
may require 25 grams. The exact requirement depends on each person's
body composition and makeup. There is no universal rule, and individualized
titration is required. The body's requirement of Vitamin C goes
up when the person is stressed. During illness, the body's bowel tolerance
to Vitamin C intake increases as the white blood cells are absorbing more
of the Vitamin C. As such, less Vitamin C remains in the bowel to cause loose
stools or diarrhea.
In Dr. Levine's study, plasma saturation in the healthy young men was not
achieved until 1,000 mg of Vitamin C daily. The plasma Vitamin C levels increased
even at a dose greater than 200 mg/day. For example, at 200 mg of Vitamin
C/ day, plasma levels were 65 uM, at 1,000 mg/day about 75 uM and at
2,500 mg/day about 85 uM. Furthermore, "tissue" levels, which were
saturated at an intake of 100 mg of Vitamin C a day were only measured in
three different types of white blood cells and not in other vital tissues
such as the liver or brain. We can therefore see the limitations of these
studies.
SIDE
EFFECTS OF Vitamin C
The side effects of Vitamin C are often
very rare. Some concerns are:
1. Pro-oxidant. Based on in vitro studies,
it has been suggested that transition metal ions may convert Vitamin C from
an effective antioxidant into a damaging pro-oxidant. Studies conducted by
the Linus Pauling Institute using human plasma and in vivo studies using guinea
pigs have proven that Vitamin C acts as
an antioxidant under in vivo conditions and not as a pro-oxidant,
even in the presence of large amounts of iron. This
hypothesis is therefore not true.
2. Kidney Stones. Urinary oxalate is an important determinant of calcium
oxalate kidney stone formation. Since Vitamin C can be metabolized to oxalate,
its role as a causative agent when taken in mega dose has been well studied.
During a study using a large group of 85,557 women with no history of kidney
stones, semi quantitative food-frequency questionnaires were used to assess
Vitamin C consumption from both diet and supplements. The study reported a
total of 1078 cases of kidney stones during the 14-year follow-up period.
Vitamin C intake was not linked with this risk. The study also mentioned that
large doses of vitamin B6 might reduce the risk of kidney stone formation
in women. The routine restriction of Vitamin
C to prevent stone formation appeared to be unwarranted.
SUMMARY
Hypercholesterolemia, cigarette smoking, hypertension, and obesity are the
main culprits for the development of artherosclerotic coronary artery disease
(CAD). However, these account only for half of the cases of CAD. The other
pathologic processes underlying atherosclerosis remains not known.
Atherosclerosis begins in the endothelium of the vascular wall. Insults
such as blood toxins and free radicals result in a damaged endothelial wall.
This causes a cascade of dysfunctional imbalances usually maintained
by the endothelial wall that includes vascular tone (blood pressure control)
and homeostasis (coagulation and therefore thrombus formation control). This
imbalance leads to an inflammatory response that attracts oxidized lipoprotein,
cholesterol and Vitamin C. The oxidative modification of low-density lipoprotein
(LDL) is important due to this proatherogenic effects.
Our body has an internal "fire-fighting team" to stop the oxidation
of LDL as a means of stopping the artherosclerotic process. It does this by
using endogenous lipophilic antioxidants such as alpha-tocopherol, beta-carotene
and Vitamin C. Vitamin C is the major water-soluble antioxidant in human plasma
and is capable of scavenging superoxide anion, which is a major source of
oxidative stress.
If we do not have sufficient amounts of
Vitamin C to effect a constant intracellular concentration, then oxidized
LDL and Lp(a) will further attract other oxidized lipids, thus resulting in
plaque formation over time. To prevent
this, we must flood our bodies with an abundant supply of Vitamin C and E.
It is also important to note that as vitamin E is fat-soluble and tend to
remain in the body, excessive amount can be toxic.
So far, we are very clear that antioxidants
prevent endothelium damage, and that oxidized ascobate is found in artherosclerotic
plaques.
Vitamin C, in conjunction with lysine and
proline, are important building blocks of collagen and the supporting
matrix of the vascular wall. During the aging process, the wear and tea of
collagen fibers must be replaced and maintained. These three nutrients
will ensure that the substrates needed for
optimum collagen building and maintenance is present. As lysine
and proline have unique features of having a high affinity for sticky lipoproteins,
plaques that are already formed can be dissolved and carried out from the
body.
The three natural compounds, Vitamin C,
lysine and proline forms a mighty trio in the fight against atherosclerosis
from at least three pathways:
1. Prevent endothelial damage that normally leads to inflammatory response
and lipoprotein adhesions.
2. Dissolve existing plaque by binding with lipoprotein and washing them out
from the body.
3. Building collagen and maintaining pliable vascular integrity normally lost
during the aging process.
Today, there is great concern that the Western diet is high in saturated fats
and trans fats, low in complex carbohydrates, high in carbohydrates and deficient
in fresh fruit and vegetables. The adoption for this form of diet has contributed
greatly to the epidemic of heart disease in the developed world.
Studies
have shown that a deficiency of the essential vitamins and minerals may contribute
to impaired endothelial function and coronary artery disease. As such, we
should supplement our bodies with Vitamin C, lysine, and proline so as to
prevent ourselves from getting heart problems.
| Message from
Dr. Lam
I hope you have enjoyed reading this
article. If you have areas you don’t understand, comments (good or
bad), or if you have a specific health concern, feel free to write
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About The Author
Michael Lam, M.D., M.P.H., A.B.A.A.M.
is a specialist in Preventive and Anti-Aging Medicine. He is currently the Director
of Medical Education at the Academy of Anti-Aging Research, U.S.A. He received
his Bachelor of Science degree from Oregon State University, and his Doctor
of Medicine degree from Loma Linda University School of Medicine, California.
He also holds a Masters of Public Health degree and is Board Certification
in Anti-aging Medicine by the American Board of Anti-Aging Medicine. Dr. Lam
pioneered the formulation of the three clinical phases of aging as well as the
concept of diagnosis and treatment of sub-clinical age related degenerative
diseases to deter the aging process. Dr. Lam has been published extensively
in this field. He is the author of The Five Proven Secrets to Longevity
(available on-line). He also serves as editor of the Journal of Anti-Aging
Research.
For More Information
For the latest anti-aging related health issues, visit Dr. Lam
at www.LamMD.com. Feel free to email
Dr. Lam at dr@LamMD.com if you have any questions.
Reprint Information
This article may, in its unabridged, unaltered form and in its entirety only,
be reprinted and republished without permission provided that it is for personal
and non commercial education use only and further provided that credit be given
to the author, with copyright notice and www.LamMD.com
clearly displayed as source. Written permission from Dr. Lam is required
for all other use.
©2002 Michael Lam, M.D. All Rights Reserved.
References
Arterioscler Thromb Vasc Biol (UNITED STATES) Oct 1995, 15 (10)
p1616-24
Casino PR, Kilcoyne CM, Quyyumi AA, Hoeg JM, Panza JA. The role of nitric oxide
in endothelium-dependant vasodilatation of hypercholesterolemic patients. Circulation.
1993;88:2541-2547.
Diaz MN, Frei B, Vita JA, Keaney JF Jr. Antioxidants and atherosclerotic heart
disease. N Engl J Med. 1997;337(6):408-416.
Freyschuss A, Xiu R-J, Zhang J, et al., Aterioscler Thomb Vasc Biol, 1997;17:1178-1184.
Iribarren C, Folson AR, Jacobs DR, et al., "Association of serum vitamin
levels, LDL susceptibility to oxidation, and autoantibodies against MDA-LDL
with carotid atherosclerosis," Arterioscler, Thromb, and Vasc Biol, 1997;17:1171-1177.
Martin A and Frei B, Arterioscler Thomb Vasc Biol, 1997;17:1583-1590.
Plotnick GD, Corretti MC, Vogel RA, "Effect of antioxidant vitamins on
the transient impairment of endothelium-dependent brachial artery vasoactivity
following a single high-fat meal," JAMA, 1997;278:1682-1686.
Vallance P, Collier J, Moncada S. Effects of endothelium-derived nitric oxide
on peripheral arterial tone in man. Lancet.1989;2:997-1000.