Matthias Rath, M.D.
Abstract
Reducing the risk for cardiovascular disease (CVD) is a primary
goal of any health care system in the industrialized world, The
success of this world-wide effort will largely depend on the proper
understanding of the mechanisms responsible for development of
this disease. This paper marshals the scientific evidence for
the predominant pathomechanisms of CVD and presents new therapeutic
approaches, Human atherosclerotic lesions are primarily composed
of lipoprotein a. The extracellular deposition of this lipoprotein
directly parallels the extent of the atherosclerotic lesion. The
frequency of this pathomechanism today is directly related to
its efficacy as a defence mechanism during the evolution of man,
particularly in stabilizing the vascular wall during ascorbate
deficiency. The deposition of lipoprotein-a in form of largely
intact particles implies the reversibility of this mechanism.
On the basis of an improved understanding about the pathogenesis
of CVD new therapeutic approaches are defined. Certain vitamins
and amino acids are of particular importance Jar these approaches.
Ascorbate is essential for preserving and restoring the integrity
and stability of the vascular wall. Niacin and ascorbate were
reported to lower lipoprotein-a plasma levels, It is proposed
that this effect is mediated by NADPH. The amino acids Lysine
and L-proline competitively interfere with the binding of lipoprotein-a
to constituents of the vascular wall and atherosclerotic lesions.
The therapeutic use of these amino acids could prevent further
build-up of lipoprotein-a accumulation in the vascular wall. More
importantly, optimum concentrations of L-lysine and L-proline
could release deposited lipoprotein-a but also other atherogenic
lipoproteins from the vascular wall, This paper defines a new
therapeutic goal: The pharmaceutical, non-invasive reversal of
existing CVD with nutritional supplements.
Introduction
Cardiovascular Disease (CVD) is the most frequent cause of death
in the industrialized world. In a series of recent papers I have
contributed to an improved understanding about the pathogenesis
of human CVD. It was shown that ascorbate deficiency is an important
underlying factor and that all mechanisms known today leading
to CVD can be triggered by ascorbate deficiency. This remarkable
fact reflects the strong pressure during the evolution of man
after loss of endogenous ascorbate synthesis. This pressure favoured
genetic and metabolic features contributing to avoidance of the
fatal consequences of ascorbate deficiency and scurvy. The different
mechanisms of human CVD known today therefore all compensate for
impaired integrity and stability of the vascular wall caused by
chronically low dietary ascorbate intake. If these mechanisms
overshoot, heart attack, stroke and other forms of CVD develop.'-'
In the first part of this paper I will marshal the evidence for
the most frequent of these pathomechanisms. I will focus here
on mechanisms related to lipid and lipoprotein deposition in the
vascular wall and re-evaluate existing hypotheses. This revaluation
is particularly necessary since cholesterol lowering concepts
have become dominant factors in the public health debate. I will
show that the most important among these overshooting defence
mechanisms is the extracellular deposition of lipoprotein-a in
the vascular wall. on the basis of an improved understanding of
these pathomechanisms I will present new therapeutic approaches
including the reversibility of existing atherosclerotic deposits.
Finally I will marshal the evidence for the particular value of
nutritional supplements to achieve this therapeutic aim.
Lipoprotein-a, not LDL, is the Primary Risk Factor for CVD in
Plasma
Present theories of human CVD are based on the concept that low-density
lipoprotein (LDL) or LDL-cholesterol is the primary risk factor
for CVD in plasma. 1.4 A closer look at the available epidemiological
data challenges this assumption. Lipoprotein-a, not LDL is the
primary risk factor for CVD in human plasma. Lipoprotein-a is
a unique particle essentially composed of a LDL particle and an
additional adhesive protein designated apoprotein-a (apo-a). The
adhesive properties of apo-a are the cause for the selective retention
of lipoprotein-a in the vascular wall and for the accumulation
of lipids and lipoproteins inside the wall (Figure 1).
Lipoprotein-a is an independent risk factor for CVD. None of
the epidemiological studies thus far assessing the plasma risk
profile for CVD showed any correlation between lipoprotein-a levels
and total-cholesterol or LDL-cholesterol levels. The most conclusive
study that lipoprotein-a, not LDL, is the primary risk factor
for CVD was carried out in a genetically defined cohort of LDL-receptor
deficient patients,' This genetic disorder is characterized by
significantly elevated plasma LDL levels and was thought to lead
almost invariably to premature CVD. Surprisingly, 60% of these
LDL-receptor deficient patients had no clinical signs of CVD,
while 40% had developed CVD. Both groups did not differ in their
extremely high plasma levels of LDL cholesterol (above 300 mg/dl)
or of total cholesterol (390 mg/dL). The two groups differed,
however, significantly in their lipoprotein-a plasma levels and
CVD patients had on average three-fold higher plasma lipoprotein-a
levels. This study in a large group of patients selected to minimize
genetic variations allows the following conclusions: 1. Elevated
plasma lipoprotein-a is the primary risk factor for CVD. 2. Increased
LDL levels, in addition to elevated lipoprotein-a levels, increase
the risk for CVD. 3. High plasma LDL levels alone are not associated
with an increased risk for CVD.
Equally strong evidence that lipoprotein-a, not LIDL, is the
primary risk factor for CVD comes from a recent re-evaluation
of the Framingham Heart Study, one of the largest prospective
epidemiological studies determining the risk profile for CVD.
Lipoprotein-a ranked among the most prevalent risk factors for
heart attacks. Moreover, a given quantity of lipoprotein-a in
the blood conferred as much added risk for CVD as does 10 times
the quantity of LDL.- Lipoprotein-a was discovered 30 years ago.7
The negligent exclusion of this important risk factor from previous
epidemiological studies deserves an explanation. It may in part
be provided by methodological difficulties as a result of the
structural similarity between lipoprotein-a and LDL. Plasma lipoproteins
in most epidemiological studies were determined by means of the
"Friedewald Formula,"8 a method that does not allow the differentiation
between LDL and lipoprotein-a. The re-evaluation of all large
epidemiological risk factor studies has become necessary. The
results of these evaluations will further confirm lipoprotein-a
as the primary risk factor for CVD, The evidence that lipoprotein-a,
not LDL, is the primary risk factor for CVD is not limited to
human plasma.
Figure 1. Schematic figures of lipoprotein-a and low-density lipoprotein
(LDL) particles. LIDL and lipoprotein-a are spherical particles
composed of lipids (predominantly cholesterol esters, triglycerides,
phospholipids), apolipoproteins (predominantly apoB-100), and
carbohydrates not shown). Lipoprotein-a shares with LDL the lipid
core and the apoproteins. The characteristic feature of lipoprotein-a
is an additional glycoprotein designated apoprotein-a (apo-a)
and is highly glycosylated. Apo-a interacts with apo 3-100 via
disulfide bonds (S-S) but also directly. Apo-a is essentially
composed of repetitive structures homologous to kringle 4 of plasminogen.
The adhesive properties of apo-a mediate the selective retention
of lipoprotein-a, as compared to other lipoproteins, in the vascular
wall.
Lipoprotein-a, not LDL, is the Primary Risk Factor Contributing
to Atherosclerotic Plaques
Present concepts of human atherosclerosis assume that LIDL is
the main vehicle by which cholesterol and other lipids are deposited
in the vascular wall. More recently it has been proposed that
cellular uptake of oxidized LDL by macrophages and other scavenger
cells and subsequent foam cell formation are the decisive mechanisms
for development of atherosclerotic plaques.4 According to this
concept foam cell formation or the extracellular deposition of
LDL would have to play a decisive role in the progression of atherosclerotic
lesions. A closer histological look on the in situ situation of
human atherosclerotic lesions challenges this concept. The progression
of atherosclerotic deposits is paralleled by a structural impairment
of the vascular wall and by the accumulation of lipoprotein-a.
Together with my colleagues at Hamburg University I reported
the most comprehensive studies differentiating between the deposition
of LDL and lipoprotein-a in human atherosclerosis."' Although
these studies are frequently quoted, their significance for the
development of human atherosclerosis is still insufficiently understood.
These studies and their correct interpretation have significant
implications for future therapeutic approaches for CVD. The conclusions
of these studies are marshalled here as follows:
1. Lipoprotein-a is the predominant risk factor contributing
to the progression of atherosclerotic lesions in man.
2. The amount of lipoprotein-a deposited in atherosclerotic lesions
corresponds with the extent of the lesions.
3. Lipoprotein-a is deposited in the extracellular matrix of
the vascular wall in the form of largely intact lipoprotein particles,
which can be isolated from the wall. This finding implies the
reversibility of the lipoprotein-a deposition in the vascular
wall.
4. Isolated LDL deposition was rarely found and LDL alone, without
simultaneous lipoprotein-a deposition, cannot be considered a
primary factor determining the advancement of human atherosclerotic
lesions.
5. The adhesive protein apo-a is responsible for the selective
retention of the lipoprotein-a particle inside the vascular wall
compared to LDL and other lipoproteins.
These results do not exclude the deposition of other potentially
atherogenic lipoproteins (LDL, very low-density lipoprotein VLDL)
in addition to and in the same areas lipoprotein-a accumulated.
The discovery of the predominant role of lipoprotein-a in human
atherosclerosis and the discovery of its potential reversibility
were decisive preconditions directly leading the way to identify
the therapeutic approaches discussed below.
Mechanism Leading to the Extracellular Accumulation of Lipoprotein-a
In the Vascular Wall
The extracellular accumulation of lipoprotein-a in the vascular
wall as the predominant pathomechanism of human atherosclerosis
is no coincidence. The frequency of this mechanism today is directly
related to its advantage during the evolution of man. After the
loss of endogenous ascorbate production in our ancestors lipoprotein-a
became a life-saving feature to counteract fatal blood-loss through
the scorbutic vascular wall. While scurvy is essentially unknown
today, chronic insufficient dietary ascorbate intake is widespread.
The deposition of lipoprotein-a in the vascular wall stabilizes
the wall of the arteries particularly during ascorbate deficiency.
With insufficient dietary ascorbate intake over decades this defence
mechanism overshoots and CVD develops.1,2 The lipoprotein-a particle
is an ideal defence molecule. Apo-a, an adhesive molecule," interacts
with a variety of cellular and extracellular constituents of the
vascular wall including collagen, elastin, fibronectin, and glycosaminoglycans;
as well as fibrin/fibrinogen. The apo-a macromolecule itself as
well as the lipoprotein-a particle confer stability to the structurally
impaired vascular wall. Moreover, the deposition of lipoprotein-a
in the vascular wall can favor the additional retention of other
lipoprotein particles such as LDL and VLDL. Lipoprotein-a has
been shown to bind to lipoproteins containing apo B 13 and the
accumulation of LDL and VLDL in addition to lipoprotein-a can
accelerate the development of atherosclerotic deposits. The CVD
risk of LDL may to a considerable extent be attributable to the
interaction with lipoprotein-a in the vascular wall. This mechanism
would explain the exponentially increased risk of elevated LDL
levels in addition to elevated lipoprotein-a levels bat not alone,
With the extracellular deposition of lipoprotein-a nature developed
a sophisticated and reversible mechanism to render compensatory
stability to the vascular wall during times when these walls are
weakened by a deficiency of essential nutrients, The reversible
deposition of lipoproteins in the vascular wall is a key to new
therapeutic approaches. To optimally exert this defence function
the lipoprotein-a particle has to be intact and it has to be deposited
extracellularly, Any degradation of the lipoprotein-a particle
would inevitably lead to a loss of its function to confer stability.
In contrast to this mechanism, present hypotheses on human atherogenesis
presuppose the degradation of the lipoprotein particles into lipids;
and amino acids by scavenging cells in the vascular wall .4 The
importance of these mechanisms in the development of human atherosclerosis
needs to be further evaluated. It is, however, evident that these
mechanisms are inferior to the extracellular deposition of lipoprotein-a
with respect to two important currant features: stability and
reversibility. This may explain why neither foam cell formation
nor the extracellular deposition of LDL are found to parallel
the progression of atherosclerotic lesions. Irrespective of the
pathomechanisms of human atherogenesis they can largely be prevented
by maintaining the structural integrity, stability, and elasticity
of the vascular wall. On the basis of an improved understanding
of human CVD presented in the first part of this paper I will
now summarize the most important preventive and therapeutic aims
for this disease.
Therapeutic Aim #I: Preserving and Restoring the Integrity and
Stability of the Vascular Wall
The impairment of the vascular connective tissue and loss of the
endothelial barrier functions are the underlying morphologic changes
of any form of CVD. The instability of the vascular wall is a
prominent risk factor for human CVD explaining the predominantly
localized clinical manifestation of this disease in form of heart
attack and stroke." 1,2 Preserving and restoring the integrity
and stability of the vascular wall is the most important therapeutic
aim for prevention and treatment of human CVD. Integrity and stability
of connective tissue are critically dependent on an optimum amount
and function of collagen and elastin. Ascorbate stimulates the
production of collagen and elastin and thereby directly contributes
to preserving and restoring the stability and integrity of the
vascular wall.14 It therefore comes as no surprise that CVD is
essentially unknown in animals producing their own vitamin C at
a daily rate of several thousand milligrams. Nor is it a surprise
that lipoprotein-a is primarily found in species that had lost
the ability of ascorbate synthesis, a discovery I made in 1987.
In humans a growing amount of clinical and epidemiological data
support the value of ascorbate in the prevention of CVD. A recent
epidemiological study in 11,000 Americans showed that dietary
ascorbate intake between 200 mg and 500 mg correlated with a reduction
in CVD up to 50% and an increase in life expectancy for up to
6 years." Beside providing structural stability to the human body,
ascorbate is also involved in a variety of enzymatic and other
metabolic functions, some of which will be discussed below.
Therapeutic Aim #2: Lowering Lipoprotein-a Levels In Plasma
Lowering the plasma levels of lipoprotein-a is the second most
important therapeutic aim. Lipoprotein-a is produced in the liver
and the production rate of apo-a largely determines the plasma
levels of this lipoprotein. None of the currently available cholesterol
lowering drugs is known to significantly affect plasma lipoprotein-a
levels. In contrast, optimum dosages of two vitamins, niacin (vitamin
B3) and ascorbate have been reported to lower lipoprotein-a plasma
levels. Their therapeutic mechanism, however, has not yet been
explained. I have obtained preliminary in vitro evidence that
lipoprotein-a production can be lowered by increasing the concentration
of NADPH. NADPH is involved in a multitude of metabolic regulatory
processes. Niacin is a constituent of the NADP molecule and ascorbate
can reduce or "re-charge" the NADP molecule to NADPH. Thus ascorbate
and niacin could decrease lipoprotein plasma levels - at least
in part - by increasing NADPH concentrations (Figure 2). Beside
the lowering of lipoprotein-a in plasma the risk for CVD can be
further reduced by preventing accumulation of this risk factor
in the vascular wall.
Therapeutic Aim #3: Preventing the Accumulation of Lipoprotein-a
in the Vascular Wall
Prevention of the accumulation of lipoprotein-a in the vascular
wall is an important therapeutic aim in reducing the risk of CVD.
As discussed above the lipoprotein-a particle can interact with
a variety of constituents of the vascular wall. The extracellular
deposition of lipoprotein-a particles in the vascular wall via
the adhesive protein apo-a immediately suggests novel therapeutic
approaches. Interfering with the binding of lipoprotein-a to constituents
of the vascular wall will decrease the tendency of this atherogenic
lipoprotein to accumulate in the vascular wall and thereby reduce
the risk for the development of atherosclerotic lesions.
Figure 2. The potential regulation of lipoprotein-a synthesis
by niacin and ascorbate via NADPH. Niacin and ascorbate have been
reported to lower plasma lipoprotein-a levels. I am proposing
that this effect is - at least in part - mediated by the reduced
form of nicotinamide adenine dinucleotide phosphate (NADPH), an
important carrier of metabolic energy involved in a multitude
of biosynthetic pathways. I have obtained preliminary evidence
that increased concentrations of NADPH decreases the synthesis
of apo-a and lipoprotein-a in vitro. Niacin essentially constitutes
the nicotinamide ring, the reactive site of the NADP and NADPH
molecule. Ascorbate reduces the NADP molecule to NADPH and thereby
"recharges" the molecule for metabolic reactions. Niacin and ascorbate
have also been shown to be effective in lowering elevated plasma
levels of low-density lipoprotein (LDL) and very low-density lipoprotein
(VLDL). Thus NADPH may also be involved in the regulation of other
potentially atherogenic lipoproteins. Further confirmation of
this therapeutic mechanism will establish the value of dietary
niacin and ascorbate supplementation in reducing elevated plasma
levels of atherogenic lipoproteins.
The amino acids L-lysine, L-proline, and hydroxyproline can interfere
with the binding of lipoprotein-a to important constituents of
the vascular wall.'"' The use of L-lysine and L-proline to prevent
the deposition of atherogenic lipoproteins in the vascular wall
opens novel therapeutic avenues. Supplementation of hydroxyproline
and hydroxylysine can be rendered redundant by co-administration
of ascorbate which can hydroxylate lysine and proline residues?
L-Lysine
The essential amino acid L-lysine competitively inhibits the binding
of lipoprotein-a to fibrinogen, fibrin, and fibrin degradation
products which are known to be hallmarks of the atherosclerotic
lesion, My earlier findings about the potential reversibility
of lipoprotein-a deposition and the isolation of lipoprotein-a
by use of lysine led to the therapeutic introduction of L-lysine
and lysine analogs in an earlier paper' (Figure 3a). I had also
suggested that optimum availability of ascorbate could convert
lysine to hydroxylysine, and by that mechanism decrease retention
of lipoprotein-a in the vascular wall.20 Subsequently Linus Pauling
reported a case history citing the beneficial effect of L-lysine
in combination with ascorbate and other essential nutrients in
a patient with CVD.21
L-proline and hydroxyproline
Trieu et al. reported that lipoprotein-a also binds to L-proline
and hydroxyproline with an even higher affinity than to lysine.
13 Since collagen and elastin are particularly rich in proline
residues this mechanism is of importance for the binding and retention
of the lipoprotein-a particle in the vascular wall. On the basis
of these observations I propose here the therapeutic use of L-proline
in the prevention and treatment of CVD. The dietary supplementation
of this amino acid should prevent the binding of lipoprotein-a
to collagen and other proline-rich constituents of the vascular
wall. and thereby prevent the accumulation of lipoprotein-a in
the vascular wall (Figure 3b). L-lysine is an essential amino
acid frequently deficient in the modem diet and the necessity
for dietary supplementation of essential amino acids is well established,
In contrast, L-proline is produced in the body from glutamate
and it may be argued that dietary supplementation with L-proline
may be unnecessary. However, no optimum amount for L-proline has
been established and the amount synthesized may frequently be
suboptimal, particularly in those patients with an increased risk
of CVD. The therapeutic value of L-lysine and L-proline is not
limited to preventing the build-up of atherosclerotic deposits,
these amino acids may also be effective in reversing existing
deposits.
Therapeutic Aim #4: Reversal of Existing Atherosclerotic Lesions
by Releasing Lipoprotein-a from the Vascular Wall
The improved understanding about human atherosclerosis and in
particular about the role of lipoprotein-a discussed in this paper
opens the way to a break-through in the treatment of CVD: the
pharmaceutical reversal of existing atherosclerotic lesions. The
key to this break-through is the reversibility of the accumulation
of lipoprotein-a in the vascular wall. Through the same mechanism
by which L-lysine and L-proline can prevent lipoprotein a deposition,
optimum concentrations of these amino acids can release accumulated
lipoprotein-a from the vascular wall, The release of lipoprotein-a
from the atherosclerotic lesions must lead to a reduction of these
atherosclerotic deposits and thereby to a reversal of existing
CVD.
Dietary supplementation of optimum amounts of L-lysine and L-proline
could contribute to releasing lipoprotein-a deposited in the vascular
wall. The experimental evidence for these novel therapeutic options
is already available. Comprehensive clinical confirmation should
soon lead to the reduction of existing atherosclerotic deposits
in CVD patients on the basis of selected nutritional supplements.
Therapeutic Aim #5: Reducing the Risk for CVD from Other Lipids
and Lipoproteins LDL
While the CVD risk for elevated LDL levels alone has to be re-evaluated,
elevated LDL levels in addition to elevated lipoprotein-a levels
are known to increase the risk for CVD exponentially.5 This fact
can be explained by the following mechanism. LDL can bind to lipoprotein-a
via proline residues (Figure 3c). This binding of LDL to lipoprotein-a
already deposited in the vascular wall can accelerate the development
of atherosclerotic lesions.
Figure 3a. The therapeutic effect of L-lysine in releasing lipoprotein-a
from the vascular wall. Lipoprotein-a and fibrinogen/fibrin are
hallmarks o human atherosclerotic lesions. lipoprotein-a binds
to fibrinogen/fibrin via lysine-binding sites. This mechanism
is part of the comprehensive defense system developed by nature
during the evolution of man to counteract blood loss through the
scorbutic vascular wall. The essential amino acid L-lysine as
well as synthetic lysine analogs can interfere with the binding
of lipoprotein-a to fibrinogen/fibrin in the vascular wall, Optimum
dietary supplementation of L-lysine can help prevent the further
deposition of lipoprotein-a in the vascular wall as well as release
deposited lipoprotein-a particles from the wall and thereby help
to decrease atherosclerotic lesions.
Figure 3b. The potential therapeutic effect of L-proline in releasing
lipoprotein-a from the vascular wall. Lipoprotein-a also binds
with high affinity to L-proline and hydroxyproline." These amino
acids are particularly enriched in collagen and other constituents
of the extracellular matrix. The direct interaction of lipoprotein-a
with the vascular connective tissue is also part of the comprehensive
defence system developed to stabilize the vascular wall during
ascorbate deficiency. The amino acids L-proline and hydroxyproline
can directly interfere with the binding of lipoprotein-a to collagen
and other matrix components. Optimum dietary supplementation of
L-proline can help prevent further deposition of lipoprotein-a
in the vascular wall as well as release deposited lipoprotein-a
particles from the wall and thereby help to decrease atherosclerotic
lesions. Dietary supplementation of hydroxyproline may be rendered
unnecessary by optimum dietary intake of ascorbate, known to convert
proline to hydroxyproline.
Figure 3c. The potential therapeutic effect of L-proline and hydroxyproline
in releasing low density lipoprotein (LDL) and other atherogenic
lipoproteins from the vascular wall. Lipoprotein-a can bind to
collagen and also bind LDL particles through the same mechanism."
This mechanism in the vascular wall is of significance for the
development of atherosclerotic deposits. Lipoprotein-a not only
contributes to the development of atherosclerosis by its own accumulation
in the vascular wall, it can also capture LDL and other lipoproteins
inside the wall, leading to an accelerated development of atherosclerotic
lesions. Optimum dietary supplementation of L-proline can therefore
not only release lipoprotein-a from the vascular wall but also
LDL and other lipoproteins retained in the wall and could thereby
lead to a further decrease of the atherosclerotic deposits.
In the light of this mechanism, lowering elevated plasma levels
of LDL remains a therapeutic aim. In numerous studies niacin as
well as ascorbate have been shown to reduce elevated plasma levels
of LDL. As with lipoprotein-a NADPH may play a regulatory role
on the synthesis rate of VLDL the precursor of LDL, Moreover,
dietary supplementation of L-proline could prevent the binding
of LDL to lipoprotein-a already deposited in the vascular wall
and, by the same mechanism, release already deposited LDL from
the atherosclerotic lesions.
VLDL
VLDL is a potentially atherogenic precursor of LDL particularly
enriched in triglycerides, Niacin and ascorbate have also been
shown to be of particular value in lowering VLDL plasma levels.
Moreover, optimum L-proline concentrations should also interfere
with the binding of VLDL inside the vascular wall.
Thus dietary supplementation of ascorbate and niacin are of particular
value to decrease the plasma levels of atherogenic lipoproteins.
Optimum dietary supplementation with the amino acids L-lysine
and L-proline could release not only lipoprotein-a but also other
atherogenic lipoproteins from the vascular wall 1. VLDL and other
triglyceride-rich lipoproteins, however, can contribute to atherogenesis
al so by another mechanism. Their enrichment in fatty acids renders
them particularly subjectible to oxidative modification and thereby
enhances their atherogenicity.
Therapeutic Aim #6: Prevention of Damage from Oxygen Free Radicals
Oxygen free radicals are promoters of atherogenesis. They lead
to structural impairment and to oxidative modification of lipoproteins
as well as other metabolic constituents. 23 Antioxidant nutrients
such as ascorbate, tocopherol (vitamin E) and beta carotene (provitamin
A) can protect against oxidative damage and against oxidative
modification of lipoproteins . Elevated plasma concentrations
of these nutrients have been shown to be associated with a decreased
risk for CVD.23,24 Nutritional supplements with antioxidative
properties, including coenzyme Q10 and selenium, contribute to
maintaining optimum cardiovascular health.
Therapeutic Aim #7: Optimum Cellular Function
Optimum function of endothelial cells, myocardial cells, smooth
muscle cells, macrophages and other cell systems critically determine
optimum cardiovascular health. Optimum metabolic function of these
cells depends on the availability of essential cofactors for a
multitude of biochemical reactions. Of particular importance are
pantothenate, a cofactor for acetyl coenzyme A, carnitine for
fatty acid transport, the B vitamins for metabolic energy transfer,
ascorbate for enzymatic hydroxylations, and coenzyme Q10 in the
respiration chain. Optimum availability of these and other essential
nutrients, including certain minerals, not only helps protect
the vascular system but also improves cardiac function," The reduction
of the risk for CVD is, of course, also dependent on other factors,
such as exercise, cessation of smoking, and a prudent diet.
Conclusion
Effective reduction of the risk for CVD is a primary goal of the
health care system in any industrialized country. In this paper
I have presented new therapeutic approaches for this disease.
Several of my earlier discoveries turned out to be of particular
importance for these recommendations: The prominent role of lipoprotein-a
in human atherosclerotic lesions urged for new therapeutic approaches;
the isolation of lipoprotein-a particles from the vascular wall
implied the reversibility of human atherosclerosis; the isolation
techniques of lipoprotein-a via lysine suggested the therapeutic
use of this amino acid to induce this reversal. The report of
the binding of lipoprotein a to proline 13 suggested the therapeutic
use of this amino acid in an analogous way. Most importantly my
earlier discovery that lipoprotein-a is primarily found in species
which had lost the ability to synthesize ascorbate triggered a
series of publications which may significantly improve our understanding
of human CVD. 1,2,20,26 Ascorbate and several other nutritional
supplements are of particular value including niacin, L-proline
and L-lysine as well as natural antioxidants. The therapeutic
use of these nutrients may pave the way towards a new therapeutic
goal: the pharmaceutical, non-invasive reversal of existing CVD
with nutritional supplements.
References
Acknowledgements
The author would like to thank Linda Pooling for helpful discussions.