Complementary Alternative Cardiovascular Medicine

34 Alternative Cardiovascular Medicine
those treated with placebo. The effect on diastolic blood pressure was not
as significant (21). In a prospective, 4-yr clinical trial of adults with atherosclerosis,
standardized garlic powder supplementation (900 mg/d)
lowered blood pressure by 7% (p < 0.05) (32). However, the AHRQ concluded
in its report that there is no evidence that garlic has a beneficial
effect on blood pressure (28).
Reported adverse events associated with garlic include cases of postoperative
bleeding during augmentation mammaplasty (42) and transurethral
resection of the prostate (43) in patients taking garlic before surgery.
There is also a report of spontaneous spinal epidural hematoma (44). None
of the patients was taking warfarin, and a direct interaction with warfarin
has not been found (45). However it is well known that antiplatelet agents
can increase the risk of major bleeding when combined with warfarin.
Practitioners should be watchful of patients who are stable on warfarin
and who add large amounts of raw garlic or garlic tablets to their diet.
In conclusion, garlic has mild, yet beneficial, effects on the cardiovascular
system and should be considered part of a heart healthy diet. Patients
who enjoy eating garlic should be encouraged to continue to do so. The
lipid-lowering effects are mild and may not be sustained, thus garlic should
be not be considered a primary therapy for patients with moderate to
severe dyslipidemia. Data are lacking to recommend garlic as a primary
therapy for hypertension.
GINKGO (GINKGO BILOBA)
Class 2 for Peripheral Vascular Disease
Standardized extracts of ginkgo are often recommended to treat intermittent
claudication. In vitro studies have demonstrated that ginkgo extract
stimulates the release of nitric oxide (NO), which induces
vasodilation by activating guanylate cyclase in the vascular smooth
muscle. Increased release of prostacyclin (PGI2) has also been demonstrated
with administration of ginkgo extracts.
Fifteen controlled trials have been conducted on ginkgo to treat intermittent
claudication—only two were considered of good quality in a 1992
meta-analysis. It was noted that all the trials, including the two best,
showed positive results in increased pain-free walking distance when
compared to placebo (46). A recent double-blind, placebo-controlled
multicenter trial of 111 patients with intermittent claudication found that
after 3 mo of taking a ginkgo extract (EGb 761), patients experienced
nearly a 50% increase in pain-free walking distance, compared to roughly
25% in the placebo group. However, adherence to taking the active or
placebo was good only seven patients (three in active and four in placebo
group) adhered to the walking exercise program (47).