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From dandelion to feverfew and meditation to acupuncture, more patients aredabbling in complementary and alternative medicines (CAMs).
By definition, CAM remedies are unproven. Few remedies have been studied inwell-controlled clinical trials. Nonetheless, CAM is becoming increasinglypopular and, in some cases, proponents suggest certain remedies might helplower hypertension.
A growing body of evidence suggests that herbal remedies can thwartdoctors' best efforts to control their patients' blood pressure. And somedrug-herb interactions may even bedeadly.1–4
THE NEED TO KNOW; THE NEED TO ASK
Cardiac surgeon Steven F. Bolling, MD, of the University of Michigan, AnnArbor, says health care professionals should ask their patients whether theyare using any CAMtherapies.
"Patients will often not tell doctors that they are taking dandelion,licorice, or things like that [because] they do not think these therapies aremedicines and they are often embarrassed to tell their doctors [for fear ofbeing ridiculed]," Bolling says.
John H. K. Vogel, MD, a cardiologist in Santa Barbara, Calif., saysphysicians have no choice but to embrace integrating CAM into theirpractices.
Vogel, who is slated to co-chair a session on complementary medicine andcardiology at the American College of Cardiology Annual Meeting in March, isauthor of a yet-to-be published expert consensus document on the integrationof complementary medicine into cardiovascular medicine.
Vogel says little is currently known about how to use CAM to managehypertension. At the same time, he says, it is undeniable that patients areusing these remedies, that they can negatively affect standard blood pressuretreatment, and that there might be a place for them in loweringhypertension—especially when it comes to a possible effect onstress.
THE DARK SIDE OF CAM
According to Bolling, surveys indicate that between 60% and 70% of peoplewith cardiovascular disease use CAM. The problem is that there can be just asmany drug-herb interactions as there are drug-drug interactions, he says.
Bolling says some people take dandelion, dandelion wine, or dandelionextract for hypertension. The herb reputedly works as a diuretic and resultsin potassium loss. However, as with many herbal supplements, reliablescientific data are scarce. If a patient taking a prescribed diuretic alsotakes dandelion, potassium loss could be exacerbated and raise the risk forcardiac arrhythmia.
Some people take yohimbine, an alpha dilator that is extracted from thebark of an African tree, for erectile dysfunction. If a person takes too muchor is taking an antidepressant, Bolling says, yohimbine could trigger ahypertensivecrisis.5,6
Vogel says that blue cohosh, used for muscle stimulation and stimulation oflabor, blocks the effect of some blood pressure medications.
Bearberry is used as a diuretic and increases the effect of digoxin, whichmany patients take to increase heart muscle activity. The danger, Vogel says,is that this herb can deplete potassium and cause toxicity of the heartmedication.
Cats claw, frequently used by people as an anti-inflammatory; cinchona,used to treat reflux; and feverfew, used to treat migraines, can increase theeffect of blood thinners, according toVogel.7
"People do not tell you that they are taking these things, and youwonder why you are having trouble regulating their blood pressuremedication," Vogel says.
TO TOUT, OR NOT TO TOUT
Even physicians who have taken the time to learn about complementarytherapies say there is not yet enough evidence to endorse their use. But somephysicians say they do not discourage patients from biofeedback, meditation,acupuncture and other therapies that might decrease stress levels and have notbeen shown to cause anyharm.
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"Both meditation and acupuncture have shown some promise in theshort-term improvement of blood pressure," says Daniel Jones, MD, of theUniversity of Mississippi Medical Center. "Most of the studies that arebeing done are not very well controlled and almost all of them are short-termstudies. Of course, there are many things that will modulate blood pressurefor the short term that do not appear to have a long-term impact on bloodpressure. That's part of the challenge in this area of study."
The evidence is "not strong enough, at this point, for anyalternative therapies," Jones says.
The biggest risk of a physician recommending complementary or alternativetherapies is that the patient might use them in lieu of blood pressuremedications, experts say.
RESEARCH IN THE WORKS
According to Leonard Egede, MD, MS, of the Medical University of SouthCarolina in Charleston, there is compelling evidence that some biologicallybased therapies might decrease blood pressure.
Studies looking at the Dietary Approaches to Stop Hypertension (DASH) diet(Blood Pressure Study Yields Cholesterol-Lowering Bonus, seepage 11), a diet rich inpotassium, magnesium, and calcium, suggest it resulted in "a reasonabledrop in systolic blood pressure of 5 to 10 mmHg," Egede says. "TheDASH studies, along with other studies, have supported the idea thatpotassium, magnesium, and calcium in higher doses are beneficial [for bloodpressure control]."
Still, Egede does not recommend that hypertensive patients replace standardtherapy with diet and supplementation. Rather, he suggests that patients whoare on medical therapy to control blood pressure get the amount of potassium,magnesium, and calcium that has been shown to be beneficial in the DASHdiet.
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Studies have suggested, Egede says, that fish oil, or omega 3 fatty acids,might have a fair effect on systolic blood pressure, lowering it by about 3mmHg.
There is also evidence to support the use of coenzyme Q10 (CoQ10). Egedesays some studies have suggested that it might help treat cardiovasculardisease and might drop systolic blood pressure by about 3 mmHg.
A recently completed but unpublished study of acupuncture's effect on bloodpressure found inconclusive evidence of actual benefit, Egede says.
There is conflicting evidence, but some studies indicate a modest effect onblood pressure from mind-body interventions, including biofeedback, behavioralmodification, meditation, breathing exercises, guided imagery and more,according to Egede. This effect can range from a 3- to a 5-mmHg drop insystolic blood pressure, depending on the study.
"I would say that because these are relatively harmless therapies, aslong as they are used as an adjunct to conventional treatments, I would not beopposed to recommending them [for stress]," he says.
In general, Egede agrees that there is little evidence to warrant aphysician recommending any CAM therapy, except for diet (which is considered amainstream treatment). He also agrees that doctors need to stress theimportance of lifestyle changes and medications so that people do notmisconstrue a physician's support of an alternative therapy as a recommendedalternative to conventional treatment.
REDUCING STRESS: A ROLE FOR SOME CAM MODALITIES?
Vogel sees some CAM methods as possible stress relievers and a way forphysicians to treat the "whole" patient.
While there is little solid evidence to support nondrug CAM therapies,Vogel says there are bits of information to consider. For instance, tranquilmusic may alleviate anxiety in preop surgery patients. Progressive musclerelaxation training and mind-body exercises with meditation might help relaxpeople, he says.
But naysayers and advocates alike question whether these would be anybetter than taking a hot bath or staring mindlessly into space. 
Footnotes
The Dietary Approaches to Stop Hypertension (DASH) diet:www.nhlbi.nih.gov/health/public/heart/hbp/dash
National Center for Complementary and Alternative Medicine:nccam.nih.gov
Natural Medicines Comprehensive Database, an impartial site providingscientific information about herbal remedies and dietary supplements:www.naturaldatabase.com
About Herbs, a site maintained by Memorial Sloan Kettering covering dietarysupplements and herbal remedies:www.mskcc.org/mskcc/html/11570.cfm
References
2. Miller KL, Liebowitz RS, Newby LK: Complementary and alternativemedicine in cardiovascular disease: a review of biologically based approaches.Am Heart J 147:401–411, 2004.[Medline]
3. Aggarwal A, Andes PA: Interactions of herbal remedies withprescription cardiovascular medications. Coron ArteryDis 12:581–584, 2001.[Medline]
4. Villegas JF, Barabe DN, Stein RA, Lazar E: Adverse effects ofherbal treatment of cardiovascular disease: what the physician must know.Heart Dis 3:169–175, 2001.[Medline]
5. Tam SW, Worcel M, Wyllie M: Yohimbine: a clinical review.Pharmacol Ther 91:215–243, 2001.[Medline]
6. Fugh-Berman A: Herb-drug interactions.Lancet 355:1019–1020, 2000.[Medline]
7. Heck AM, DeWitt BA, Lukes AL: Potential interactions betweenalternative therapies and wafarin. Am J Health SystPharm 57:1221–1227, 2000.
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