Complementary Alternative Cardiovascular Medicine

102 Alternative Cardiovascular Medicine
bidity. There is widespread public interest in the use of alternative medicine
to prevent and treat these diseases. The cardiovascular system is
more susceptible to free radical oxidative stress and premature aging
than any other body system. Certain herbal and dietary factors have
antioxidant, anti-inflammatory, and antiproliferative properties. Therefore,
select supplements may play a preventive and therapeutic role in
CVD. Conflicting reports in the biomedical literature and lack of information
from health care professionals have led to the misunderstanding
about supplements’ roles in patients with CVDs. This chapter reviews
the most commonly used nutrachemicals.
L-ARGININE
L-arginine is an essential amino acid and is required for protein synthesis.
It is found in red meat, fish, poultry, and dairy products. Nitric
oxide synthase (NOS) converts L-arginine to nitric oxide (NO) in vascular
endothelial cells. NO is also known as the endothelial-derived relaxation
factor (EDRF). NO is a potent vasodilator and modulates a
significant portion of endothelial function in coronary and peripheral
circulations. These beneficial effects can be jeopardized if there is
impaired NO production. It is postulated that a reduction in available
L-arginine, in part because of the presence of endogenous inhibitors, will
result in impaired NO production and endothelial dysfunction. Therefore,
L-arginine administration could enhance endogenous NO production,
which could result in favorable clinical outcomes.
Role in CVD
Studies have shown beneficial effects of L-arginine supplementation
in a relatively small number of patients with coronary artery disease
(CAD). Lerman et al. (1) reported the beneficial effects of oral supplementation
of L-arginine in 26 patients with small-vessel CAD. Coronary
blood flow (CBF) reserve in response to acetylcholine was assessed at
baseline and at 6-mo intervals. In this small, blinded, controlled trial, the
L-arginine group demonstrated a significant increase in CBF compared
with placebo (149 ± 20% vs 6 + 9%, p < 0.05). This finding was also
associated with decreased plasma endothelin level, which is a potent
vasoconstrictor. It has been postulated that increased NO production
may inhibit the endothelin production through a cyclic guanosine monophosphate
(cGMP) dependent pathway. Blum et al. (2) illustrated the
benefits of oral L-arginine therapy (9 g/d for 3 mo) in a crossover, doubleblind
study of 10 patients with intractable class IV angina, despite treatment
with aspirin, calcium channel blockers, nitrates, and high-dose