Congestive Heart Failure and Hypercholesterolemia - Alternative Therapies, part 2

Author: Vincent Morelli, Roger J. Zoorob
Date: Sept 15, 2000

Natural supplements are widely used by the American public but, while claims of their therapeutic effects abound, medical research does not always support their effectiveness. Clinical trials using Q10 for the management of congestive heart failure have had conflicting results; hawthorn is prescribed in Germany for the treatment of this condition, but no trials have been conducted in the United States. Although initial research about the use of garlic in the management of hypercholesterolemia was encouraging, follow-up studies have failed to verify these results. Substituting soy protein for high-fat animal protein diets, however, does have a beneficial effect on serum lipid levels. So far, cholestin (a natural product containing several statins) has proved to be a cost-saving lipid-lowering medication, and fenugreek may offer modest improvement as well. Gugulipid is also promising but requires further research. (Am Fam Physician 2000;62:1325-30.)

In 1997, Americans spent more than $12 billion on natural supplements; a 1993 study showed that one third of Americans polled used some form of alternative medicine.(1) Family physicians must be aware of the widespread use of these products. We must be able to separate anecdotal from evidence-based benefits, and we must be aware of side effects and potential interactions between medications and herbs or supplements if we are to offer informed consultation to our patients.

American Family Physician has previously published articles that focus on herbal products and their side effects, as well as herb/drug interactions.(2,3) The first part of this article, published in the previous issue, reviewed the use of herbs and supplements in the management of diabetes, depression and obesity. This part of the article highlights the role that supplements can play in the management of two other conditions commonly encountered in the family physician's office: congestive heart failure and hypercholesterolemia. Table 1 summarizes information about the natural products discussed.

Congestive Heart Failure

Of the many adjunctive treatments for congestive heart failure (CHF), two of the most widely publicized in recent years are Q10 and hawthorn.

Ubiquinone: Q10

Q10 is a coenzyme found in all tissues of the body (hence its common name, ubiquinone). It is necessary for certain metabolic reactions, including oxidative respiration, and its concentration is increased in the heart, liver and pancreas. Its use in heart disease stems from its antioxidant effects, its stabilization of sodium- and potassium-activated adenosine triphosphate (NaK ATPase) and its effect on calcium channels.(4)

To date, the clinical benefits of Q10 supplementation have not been clearly proved. Two well-researched meta-analyses(5) have shown improved ejection fractions, stroke volume, cardiac output, cardiac index and end diastolic volume in patients taking Q10 supplement; each also suggested that Q10 may have a role in the treatment of CHF. However, the clinical significance of these findings has not yet been proved.

In clinical trials, a 1999 study(6) showed that 22 patients enrolled in a randomized, double-blind, placebo-controlled, crossover trial of Q10 experienced an increased stroke index at rest and at work and a decreased pulmonary capillary wedge at rest. The study concluded that patients with congestive heart failure may benefit from supplementation with Q10. Two other recent clinical trials(7,8) refuted this finding. A randomized, double-blind, placebo- controlled, crossover trial(7) evaluated 30 patients for three months and found no increase in resting systolic function despite plasma levels of Q10 that were twice the normal baseline values. Another randomized, double-blind, placebo-controlled, crossover study8 of 79 patients with CHF measured ejection fraction, exercise tolerance and quality of life. This study found a nonsignificant increase in ejection fraction and, possibly, a slightly increased exercise tolerance and slightly increased subjective quality of life in the subjects taking Q10

In light of the above evidence, it can be concluded that if Q10 has a beneficial role in the management of CHF, it is modest at best. These studies found no adverse side effects of Q10 at dosages of 100 mg daily for six years or 200 mg daily for one year.

HAWTHORN

The hawthorn plant contains pharmacologically active flavonoids that inhibit vasoconstriction and actively dilate blood vessels. One of these flavonoids has also been reported to block vasoconstriction by inhibiting angiotensin-converting enzyme. These actions, as well as in vitro increases in coronary circulation (from 20 to 140 percent) and inhibition of the adenosine 3',5'-cyclic monophosphate phosphodiesterase, give hawthorn its theoretic basis for use in congestive heart failure.(9)

As for its actual observed effect in human studies, a 1996 review(10) of German literature concludes that rigorous clinical trials have shown benefit in objective signs and subjective symptoms of stage II CHF. A multicenter, placebo-controlled, double-blind trial(11) studied 136 patients with stage II CHF. A clear improvement in the subjects receiving hawthorn was observed and documented as an improvement in the pressure-heart rate product, while the conditions of the subjects receiving placebo deteriorated. The hawthorn group also had a subjective improvement in quality of life and mental well-being. The study concluded that hawthorn was an effective, low-risk phytotherapeutic form of treatment in patients with stage II cardiac insufficiency.(11) Hawthorn is sold as a prescription medication in Europe and Asia. In Germany, it has been approved and is prescribed for mild cardiac insufficiency.

Despite studies mentioned in the German literature, we did not find that any double-blind, randomized, placebo-controlled, crossover trials had been performed in the United States, nor could we find any studies documenting echocardiographic improvements or improvements in exercise tolerance.

Because hawthorn may potentiate the action of cardiac glycosides and may interfere with digoxin or digoxin monitoring, it has been recommended that patients using digitalis or other cardiovascular drugs refrain from using hawthorn unless monitored by a physician. Neither we nor the authors of a 1998 review12 could find any clinical studies documenting this potential interaction.

Hypercholesterolemia

GARLIC

Despite the many early promising studies and meta-analyses evaluating garlic's effect as a lipid-lowering agent, more recent, rigorous studies have failed to substantiate these benefits.(13-16) There is no current role for garlic as an antihyperlipidemic agent.

SOY

The precise mechanism by which soy proteins are thought to decrease serum lipid levels is unclear. Possible mechanisms include decreased cholesterol absorption, decreased bile reabsorption in the gut or possibly a change in endocrine status associated with biologically active substances such as isoflavones (phytoestrogens) or saponins present in soy.(17) Several well-conceived animal studies(18-20) have clearly shown a decrease in total cholesterol and low-density lipoprotein (LDL) levels when dietary soy protein was substituted for animal protein. Human observational studies, as well as human intervention trials, have also shown soy's beneficial effect on levels of total cholesterol and LDL.(21) A recent meta-analysis(22) also showed a trend toward decreased cholesterol levels and decreased LDL levels among subjects taking soy, with an average decrease of 9 percent in total cholesterol levels, 13 percent in LDL levels and 10 percent in triglyceride levels.

In 1998, Potter and associates(23) corroborated this meta-analysis and found that consumption of soy protein, substituted for animal fat, lowered total cholesterol levels an average of 6 percent and non-high-density lipoprotein cholesterol levels by 7 percent in postmenopausal women with hypercholesterolemia. In 1998, Wong and colleagues(24) demonstrated similar lipid-lowering effects in men with normal cholesterol levels and men with hypercholesterolemia.

In October 1999, the U.S. Food and Drug Administration approved a "health claim" labeling for soy products. It was concluded that, "Diets low in saturated fat and cholesterol that include 25 g of soy protein may reduce the risk of heart disease." To carry the health claim labeling, foods must contain at least 6.25 g of soy per serving and be low in fat, saturated fat and cholesterol. In reviewing all of the literature, consumption of at least 25 g of soy per day is needed to see a decrease in levels of cholesterol and LDL. Table 2 includes some of the more common sources of soy and their soy protein content.

CHOLESTIN

(33.) Agarwal RC, Singh SP, Saran RK, Das SK, Sinha N, Asthana OP, et al. Clinical trial of gugulipid--a new hypolipidemic agent of plant origin in primary hyperlipidemia. Indian J Med Res 1986;84:626-34.

(34.) Singh RB, Niaz MA, Ghosh S. Hypolipidemic and antioxidant effects of Commiphora mukul as an adjunct to dietary therapy in patients with hypercholesterolemia. Cardiovasc Drugs Ther 1994;8: 659-64.

This is Part II of a two-part article on alternative therapies. Part I, on alternative therapies for depression, diabetes and obesity appeared in the last issue (Am Fam Physician 2000; 62:1051-60.)

TABLE 1Summary of Natural Products Used in the Management of Cardiac DisordersProduct Other names EfficacyCongestive heart failure (CHF)Q10 Ubiquinone Modest, at bestHawthorn Crataegus Incomplete, species, but highly haw, may, promising whitethorn data; approved for use in Germany and Asia for mild cases of CHFHypercholesterolemiaGarlic Allium sativum, Not efficacious poor man's treacleSoy Glycine soja Proved efficacy; will decrease total cholesterol 5 to 9%, LDL 13%Cholestin Went yeast, As efficacious Monascus as commercial purpureus, statins fermented on riceGugulipid/ Commiphora Preliminary dataguggal gum molmol, promising; Arabian myrrh, needs larger Somalian controlled myrrh studies; widely used in India MechanismProduct of action FormulationCongestive heart failure (CHF)Q10 Antioxidant; Liquid, positive capsules ionotropeHawthorn Vasodilatory Dry extracts effects; or liquid increased coronary flow; decreased peripheral resistance; ACE- inhibitor- like effectHypercholesterolemiaGarlic None Fresh, oil, aqueous, fermented or driedSoy Estrogen-like Extract properties; alters hepatic cholesterol metabolismCholestin HMG CoA Capsules reductase inhibitorGugulipid/ Increased Extractguggal gum hepatic LDL powdered binding resin; sites[*] concentrated tabletsProduct Dosage/interval Side effectsCongestive heart failure (CHF)Q10 100 to 200 mg None recorded per dayHawthorn Average daily None recorded dosage: 5 g or 160 to 900 mg extract for a minimum of 6 weeksHypercholesterolemiaGarlic Large quantities can cause stomach complaintsSoy Average daily Possible dosage: occasional 25 g soy stomach protein pain, loose stool and diarrheaCholestin 1,200 mg Possible liver twice daily enzyme elevation and myositis; none, however, recordedGugulipid/ 75 mg per day None recorded[]guggal gum DrugProduct interactionsCongestive heart failure (CHF)Q10 None recordedHawthorn May interfere with digoxin or digoxin monitoringHypercholesterolemiaGarlic None recordedSoy None recordedCholestin Same as commercially available statinsGugulipid/ None recordedguggal gumACE = angiotensin-converting enzyme; LDL = low-density lipoprotein;HMg CoA = human menopausal gonadotropin coenzyme A.[*]--Information from Singh V, Kaul S, Chander R, Kapoor NK.Stimulation of low density lipoprotein receptor activity in livermembrane of guggulsterone-treated rats. Pharmacol Res 1990;22:37-44.[]--Information from Lawrence Review of Natural Products.Guggul. St. Louis, Mo.: Facts and Comparisons, 1995.TABLE 2Sources of Soy Soy proteinSource content1 cup of soy milk 3 to 10 g4 oz of tofu 5 to 13 g11/42 cup of textured soy protein 6 to 11 g11/42 cup of soy flour 20 g3 tablespoons soy protein isolate 22 g

COPYRIGHT 2000 American Academy of Family PhysiciansCOPYRIGHT 2000 Gale Group

 
© 2006, DrPlace.com, All Rights Reserved.