English Hawthorne Herbal Extract
Also known as: Crataegus laevigata, C. oxyacantha, C. monogyna, Hawthorn, Maythorn, Whitethorn
Overview
Hawthorn (Crataegus spp.) leaf and flower extracts are used as a cardiovascular herbal supplement, particularly for individuals with mild to moderate heart failure (NYHA Class I-III). These extracts are typically standardized to contain 2-3% flavonoids or 18-20% oligomeric procyanidins (OPCs). Research suggests that hawthorn can improve exercise tolerance and reduce cardiac workload when used as an adjunct therapy. The primary active compounds include oligomeric procyanidins (OPCs), flavonoids like vitexin and hyperoside, and triterpenes. While research maturity is moderate, several meta-analyses support its benefits, though updates are needed to reflect the latest findings. It is available in various forms, including capsules, tablets, and liquid extracts.
Benefits
Hawthorn extract has shown promise in several key areas. It significantly improves exercise tolerance, with studies showing an average increase of 7W in maximum workload. It also reduces cardiac workload, as indicated by a decrease in the pressure-heart rate product. Symptom relief, particularly in dyspnea and fatigue, has been observed compared to placebo. Additionally, hawthorn may have blood pressure-modulating effects and antioxidant activity, although the evidence for these benefits is primarily mechanistic or derived from in vitro and animal studies. The most robust evidence supports its use as an adjunct therapy for individuals with mild to moderate heart failure.
How it works
Hawthorn exerts its effects through several mechanisms. It acts as a positive inotrope by increasing calcium sensitivity in cardiomyocytes, which enhances heart muscle contraction. It also promotes vasodilation by activating endothelial nitric oxide synthase, leading to improved blood flow. Additionally, hawthorn has antiarrhythmic properties through potassium channel modulation. The bioavailability of OPCs, a key component, is around 20-40%, with peak plasma concentrations reached within 2-3 hours after ingestion. These combined actions contribute to its cardioprotective effects.
Side effects
Common side effects of hawthorn extract are generally mild and include nausea and dizziness, with an incidence rate of 3-5%. Rare side effects such as palpitations have been reported in less than 1% of users. Hawthorn can potentiate the effects of cardiac glycosides, beta-blockers, and antihypertensive medications, necessitating careful monitoring when used in conjunction with these drugs. It is contraindicated in acute heart failure and during pregnancy due to insufficient safety data. Individuals should consult with a healthcare professional before using hawthorn, especially if they have pre-existing heart conditions or are taking other medications.
Dosage
The effective dosage range for hawthorn extract is typically between 300-900mg per day, standardized to 18% OPCs. An optimal dosage is often considered to be 600mg daily, divided into three doses taken with meals. Short-term use of up to 1,800mg per day has been reported, but long-term safety at this level is not well-established. Clinical effects usually manifest after 4-8 weeks of consistent use. It's important to note that individual responses may vary, and it is advisable to start with a lower dose and gradually increase as tolerated.
FAQs
Can hawthorn replace heart medications?
No, hawthorn extract is intended for adjunctive use only. Studies have demonstrated its effectiveness when used alongside conventional heart failure treatments, not as a replacement.
Does hawthorn affect blood pressure?
Hawthorn may have mild blood pressure-reducing effects due to its vasodilatory properties. However, it should not be used as a primary treatment for hypertension without medical supervision.
How long does it take to see the effects of hawthorn?
Clinical benefits from hawthorn extract typically become noticeable after 8 weeks or more of consistent use. It is important to maintain regular dosing to achieve the desired effects.
Research Sources
- https://www.ncbi.nlm.nih.gov/books/NBK69639/ – This source provides general information about herbal supplements, including hawthorn. It may offer background context and general usage information, but specific study details are not available in this summary.
- https://pubmed.ncbi.nlm.nih.gov/12798455/ – This meta-analysis of 8 RCTs (n=632) in NYHA Class I-III heart failure patients found that hawthorn extract significantly increased workload capacity by 7W (p<0.01) and provided symptom relief. The authors noted limitations due to the heterogeneity of the hawthorn preparations used in the included studies.
- https://onlinelibrary.wiley.com/doi/full/10.1016/j.ejheart.2008.10.003 – This post-hoc analysis of the SPICE trial, involving 2,681 patients, supports the long-term safety profile of hawthorn extract. However, the evidence is indirect, derived from observational data rather than a dedicated safety study.
- https://www.mountsinai.org/health-library/herb/hawthorn – This clinical practice guideline classifies hawthorn as "likely effective" for congestive heart failure (CHF). It is a narrative review that summarizes existing evidence and provides clinical recommendations, but it does not offer a systematic analysis of the literature.
- https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=043482c6746d1209c8658690b124f88d1a4d42df – This document provides information on the mechanisms of action of hawthorn, including its effects on vasodilation and cardiac function. It also discusses the bioavailability of OPCs and potential drug interactions. The document classifies hawthorn as "likely effective" for CHF.