Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.
For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.
3 StarsReliable and relatively consistent scientific data showing a substantial health benefit.
2 StarsContradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1 StarFor an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.
This supplement has been used in connection with the following health conditions:
Congestive Heart Failure
80 to 300 mg of standardized herbal extract two to three times per day with a doctor's supervision
Antioxidant hawthorn appears to reduce symptoms and improve exercise capacity by increasing blood flow to the heart and the strength of heart contractions, and reducing resistance to blood flow in the extremities.
Clinical trials have shown that standardized extracts made from the leaves and flowers of hawthorn are effective in helping people with early-stage CHF.1, 2, 3 Hawthorn extracts appear to increase blood flow to the heart, increase the strength of heart contractions, reduce resistance to blood flow in the extremities, and act as an antioxidant.4, 5, 6 In a large preliminary trial, people with mild to moderate CHF were given 300 mg of hawthorn flower and leaf extract (standardized to contain 2.2% flavonoids) three times a day for two months.7 Symptoms of CHF—including heart palpitations, chest pressure, and swelling in the extremities—decreased throughout the trial during the use of hawthorn. The efficacy of hawthorn for the treatment of CHF has been confirmed in a double-blind trial.8
Hawthorn extracts are available in capsules or tablets standardized to either total flavonoid content (usually 2.2%) or oligomeric procyanidins (usually 18.75%). Doctors who work with herbal medicine often suggest 80–300 mg two to three times per day. Hawthorn berry products that are not standardized may be weaker, and the recommended amount is typically 4 to 6 grams per day for the whole herb, or 4–5 ml of the tincture three times per day.
60 mg of an herbal extract containing 18.75% oligomeric procyanidins taken three times per day
Parts of the hawthorn tree contain flavonoids that may protect blood vessels from damage. Taking hawthorn extract improved heart function and exercise tolerance in angina patients in one trial.
The fruit, leaves, and flowers of the hawthorn tree contain flavonoids, including oligomeric procyanidins, which may protect blood vessels from damage. A 60 mg hawthorn extract containing 18.75% oligomeric procyanidins taken three times per day improved heart function and exercise tolerance in angina patients in a small clinical trial.9
Cardiomyopathy and Congestive Heart Failure
160 to 900 mg daily of a standardized herbal extract with a doctor's supervision
Studies have found hawthorn to be effective for the signs and symptoms of early-stage congestive heart failure, the main complication of cardiomyopathy.
Many doctors expert in herbal medicine consider hawthorn to be an effective and low-risk therapy for congestive heart failure, the main complication of cardiomyopathy. Rigorous clinical trials have now confirmed the effectiveness of hawthorn for the signs and symptoms of early-stage congestive heart failure,10, 11, 12, 13, 14 though hawthorn studies with cardiomyopathy patients have yet to be conducted. The clinical trials with heart-failure patients have demonstrated efficacy using 80 to 300 mg of standardized extract of hawthorn leaves and flowers two to three times per day.
1,200 mg per day of an herbal extract standardized to 2.2% flavonoids
Hawthorn leaf and flower extracts have been reported to have a mild blood pressure–lowering effect.
Hawthorn leaf and flower extracts have been reported to have a mild blood pressure–lowering effect in people with early stage congestive heart failure.15 In a double-blind study, supplementation with a hawthorn extract significantly decreased diastolic blood pressure in people with type 2 diabetes. The amount used was 1,200 mg per day of an extract standardized to 2.2% flavonoids corresponding to 6 grams per day of dried flowering tops.16
Refer to label instructions
Hawthorn has been used traditionally to reduce the frequency of arrhythmias.
An animal study showed that an extract of hawthorn significantly reduced the number of experimentally induced arrhythmias.17 Although the use of hawthorn for arrhythmia in humans has not been studied scientifically, it traditionally has been used for this purpose.18
Traditional Use (May Not Be Supported by Scientific Studies)
Dioscorides, a Greek herbalist, reportedly used hawthorn in the first century A.D. Although numerous passing mentions are made for a variety of conditions, support for the heart is the main benefit of hawthorn.
The leaves, flowers, and berries of hawthorn contain a variety of bioflavonoids that appear to be primarily responsible for the cardiac actions of the plant. Flavonoids found in hawthorn include oligomeric procyanidins (OPCs), vitexin, vitexin 4’-O-rhamnoside, quercetin, and hyperoside. These compounds are often standardized in leaf and flower extracts, which are widely used in Europe.
Hawthorn is thought to exert many beneficial effects on the heart and blood vessels. These include improved coronary artery blood flow and strengthening of the contractions of the heart muscle.19 Hawthorn may also improve circulation to the extremities by lowering the resistance to blood flow in peripheral blood vessels.20 The bioflavonoids in hawthorn are potent antioxidants.21 Hawthorn extracts may mildly lower blood pressure in some people with high blood pressure but should not be thought of as a substitute for cardiac medications for this condition.
Clinical trials have confirmed that hawthorn leaf and flower extracts are beneficial for people with stage II (early-stage) congestive heart failure.22, 23, 24, 25, 26 People with congestive heart failure taking 160–900 mg of hawthorn extract per day for eight weeks showed improved quality of life including greater ability to exercise without shortness of breath and exhaustion. Congestive heart failure is a serious medical condition that requires expert management rather than self-treatment. One study has shown that hawthorn leaf and flower extract may also help those with stable angina.27
How to Use It
Extracts of the leaves and flowers are most commonly used in modern herbal medicine. Hawthorn extracts standardized for total bioflavonoid content (usually 2.2%) or oligomeric procyanidins (usually 18.75%) are often suggested. Many doctors recommend 80–300 mg of the herbal extract in capsules or tablets two to three times per day.28 If traditional berry preparations are used, the recommendation is at least 4–5 grams per day or a tincture of 4–5 ml three times daily. However, this form has not been clinically studied. Hawthorn is slow acting and may take one to two months for maximum effects to be seen. However, it appears to be safe and should be considered a long-term therapy.
Interactions with Supplements, Foods, & Other Compounds
People taking prescription cardiac medications should consult with their doctor before using hawthorn-containing products. Reports of hawthorn interacting with digitalis to augment its effects have not been confirmed in clinical trials.
Hawthorn (Crataegus oxyacantha, Crataegus monogyna) (leaf with flower) extract is approved in Germany to treat mild congestive heart failure.29 Congestive heart failure is a serious medical condition that requires expert medical management rather than self-treatment. Due to the narrow safety index of digoxin, it makes sense for people taking digoxin for congestive heart failure to consult with their doctor before using hawthorn-containing products. Reports of hawthorn interacting with digitalis to enhance its effects have not been confirmed.
The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a supplement with your doctor or pharmacist.
1. Leuchtgens H. Crataegus special extract (WS 1442) in cardiac insufficiency. Fortschr Med 1993;111:352–4.
2. Schmidt U, Kuhn U, Ploch M, Hübner WD. Efficacy of the hawthorn (Crataegus) preparation LI 132 in 78 patients with chronic congestive heart failure defined as NYHA functional class II. Phytomed 1994;1:17–24.
3. Pittler M, Guo R, Ernst E. Hawthorn extract for treating chronic heart failure. Cochrane Database Syst Rev 2008 Jan 23;(1):CD005312.
4. Maevers VW, Hensel H. Changes in local myocardial blood flow following oral administration of a Crataegus extract to non-anesthetized dogs. Arzneimittelforschung 1974;24:783–5.
5. Weikl A, Noh HS. The influence of Crataegus on global cardiac insufficiency. Herz Gerfässe 1992; 11:516–24.
6. Bahorun T, Trotin F, Pommery J, et al. Antioxidant activities of Crataegus monogyna extracts. Planta Med 1994; 60:323–8.
7. Schmidt U, Albrecht H, Podzuweit M, et al. High-dose crataegus therapy in patients suffering from congestive heart failure NYHA class I and II. Z Phytotherapie 1998;19:22–30.
8. Rietbrock N, Hamel M, Hempel B, et al. Actions of standardized extract of Crataegus berries on exercise tolerance and quality of life in patients with congestive heart failure [in German]. Arzneimittelforschung 2001;51:793–8.
9. Hanack T, Bruckel MH. The treatment of mild stable forms of angina pectoris using Crataegutt® novo. Therapiewoche 1983;33:4331–3 [in German].
10. Weikl A, Assmus KD, Neukum-Schmidt A, et al. Crataegus Special Extract WS 1442. Assessment of objective effectiveness in patients with heart failure. Fortschr Med 1996;114:291–6 [in German].
11. Weihmayr T, Ernst E. Therapeutic effectiveness of Crataegus. Fortschr Med 1996;114:27–9 [in German].
12. Leuchtgens H. Crataegus Special Extract WS 1442 in NYHA II heart failure. A placebo controlled randomized double-blind study. Fortschr Med 1993;111:352–4 [in German].
13. Schmidt U, Kuhn U, Ploch M, Hübner WD. Efficacy of the hawthorn (Crataegus) preparation LI 132 in 78 patients with chronic congestive heart failure defined as NYHA functional class II. Phytomed 1994;1:17-24.
14. Pittler M, Guo R, Ernst E. Hawthorn extract for treating chronic heart failure. Cochrane Database Syst Rev 2008 Jan 23;CD005312.
15. Schmidt U, Kuhn U, Ploch M, Hübner W-D. Efficacy of the hawthorn (Crataegus) preparation LI 132 in 78 patients with chronic congestive heart failure defined as NYHA functional class II. Phytomed 1994;1(1):17–24.
16. Walker AF, Marakis G, Simpson E, et al. Hypotensive effects of hawthorn for patients with diabetes taking prescription drugs: a randomised controlled trial. Br J Gen Pract 2006;56:437–43.
17. Al Makdessi S, Sweidan H, Dietz K, Jacob R. Protective effect of Crataegus oxycantha against reperfusion arrhythmias after global no-flow ischemia in the rat heart. Basic Res Cardiol 1999;94:71–7.
18. Ellingwood F. American Materia Medica, Therapeutics and Pharmacognosy. Sandy, OR: Eclectic, 1919, 217–20.
19. Weikl A, Noh HS. The influence of Crataegus on global cardiac insufficiency. Herz Gefabe 1993;11:516–24.
20. Loew D. Pharmacological and clinical results with Crataegus special extracts in cardiac insufficiency. ESCOP Phytotelegram 1994;6:20–6.
21. Bahorun T, Trotin F, Pommery J, et al. Antioxidant activities of Crataegus monogyna extracts. Planta Med 1994;60:323–8.
22. Weihmayr T, Ernst E. Therapeutic effectiveness of Crataegus. Fortschr Med 1996;114:27–9 [in German].
23. Schmidt U, Kuhn U, Ploch M, Hübner W-D. Efficacy of the Hawthorn (Crataegus) preparation LI 132 in 78 patients with chronic congestive heart failure defined as NYHA functional class II. Phytomed 1994;1:17–24.
24. Leuchtgens H. Crataegus special extract WS 1442 in heart failure, NYHA II. A placebo-controlled randomized double-blind study. Fortschr Med 1993;111:352–4.
25. Weikl A, Assmus KD, Neukum-Schmidt A, et al. Crataegus special extract WS 1442: Objective proof of efficacy in patients withy cardiac insufficiency (NYHA II). Fortschr Med 1996;114:291–6.
26. Tauchert M, Ploch M, Hübner W-D. Effectiveness of hawthorn extract LI 132 compared with the ACE inhibitor Captopril: Multicenter double-blind study with 132 patients NYHA stage II. Münch Med Wochenschr 1994;132(suppl):S27–33.
27. Hanack T, Brückel M-H. The treatment of mild stable forms of angina pectoris using Crataegutt (R) Novo. Therapiewoche 1983;33:4331–3 [in German].
28. Brown DJ. Herbal Prescriptions for Better Health. Rocklin, CA: Prima Publishing, 1996, 139–44.
29. Blumenthal M, ed. The Complete German Commission E Monographs. Austin, TX: American Botanical Council, 1998, 143.
The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2014.
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