Hawthorn, a thorny shrub in the rose family, which is native to Europe and parts of Africa and Asia, produces small red or black berries called haws. Hawthorn has been a mainstay of traditional herbal medicine for the treatment of heart ailments since the first century. Though research has largely supported the use of hawthorn for hypertension, consult a qualified health professional before supplementing with hawthorn.
Good for Diabetics
Hawthorn reduced elevated blood pressure in diabetics in a study by A.F. Walker et al published in the June 2006 "British Journal of General Practice." Participants with type 2 diabetes took 1200mg of hawthorn per day for 16 weeks and as a result had a significant reduction in diastolic blood pressure. No change in systolic pressure was noted.
Effective at Low Doses
Low doses of hawthorn had blood pressure-lowering effects in mild hypertension in a study published in the February 2002 "Phytotherapy Research" journal by A.F. Walker et al. Volunteers took 500mg of hawthorn extract per day for 10 weeks, after which the researchers observed a decline in both systolic and diastolic levels. Hawthorn also resulted in decreased anxiety.
Preparations
Some hawthorn supplements are more effective than others for lowering blood pressure, according to a study published in the December 2008 "Journal of Medicinal Foods" by researchers M.E. Rodrigues et al. The study compared two preparations of hawthorn, one containing flowers, leaves and berries, and the other containing only berries, on rat heart cells. Markedly different effects were observed. The researchers cautioned that dire consequences could result for patients who supplant prescription medications with commercial hawthorn preparations.
Safety
Hawthorn is relatively safe, however a small percentage of severe reactions were noted in a report by C. Daniele et al in a review study published in the 2006 "Drug Safety" journal. The review study included over 5,500 patients who took doses of hawthorn anywhere between 160mg to 1,800mg per day for anywhere between three to 24 weeks. Most adverse effects were mild to moderate and included dizziness, stomach upset, headache, and heart palpitations. No drug interactions occurred. However, eight severe effects were noted, leading the authors to caution that unsupervised use of hawthorn may lead to problems.
References
- PubMed.gov: A comparison of the effects of commercially available hawthorn preparations on calcium transients of isolated cardiomyocytes
- "British Journal of General Practice": Hypotensive effects of hawthorn for patients with diabetes taking prescription drugs: a randomised controlled trial
- PubMed.gov: Promising hypotensive effect of hawthorn extract: a randomized double-blind pilot study of mild, essential hypertension
- PubMed.gov: Adverse-event profile of Crataegus spp.: a systematic review
- University of Maryland Medical Center: Hawthorn
