Hawthorn (Crataegus monogyna) is a shrub-like, thorny tree that shares its genus with approximately 280 members of the Rosaceae family, including the rose. The herb is commonly known as mayblosson and the fruit as haw. Although the fruit does resemble a berry, it is actually a pome, the name given to a type of fruit that contains one or more kernels or stones similar in appearance to the pit of a peach.
Like many herbs of significance to naturopathic and homeopathic medicine, hawthorn berry was celebrated for its healing properties long before evidence-based medicine could validate its benefits. For instance, in Scotland and Wales, a centuries old tradition is to place an offering at the site of ancient wells to solicit nature spirits to effect a healing. Since the offering is often in the form of a cloot, or strip of cloth, these sacred sites are known as clootie wells. Hawthorn is typically found growing near these wells, so visiting patrons often “seal” their healing rituals by tying their cloot to its branches. In fact, this association is referenced in an old Celtic adage that advises, “'When all fruit fails, welcome haws.”
To modern scientists, the medicinal properties of hawthorn berry can be attributed to the presence of certain bioflavonoids, most notably oligomeric procyanidins. Research has shown that these agents provide antioxidant activity and may help to improve the elasticity of blood vessels, thereby enhancing circulation, reducing cholesterol levels, and lowering blood pressure. Several studies have investigated the effects of these compounds on the heart in particular, the findings of which suggest that hawthorn berry may improve heart function in patients diagnosed with heart failure. Not only did patients consistently experience significantly reduced palpitations, fatigue, and shortness of breath in these studies, but were also able to reduce the amount of prescription medications taken to treat these symptoms. In fact, one study demonstrated that the effects of supplementing with hawthorn berry for 60 days was comparable to low doses of the heart medication captropril.
Hawthorn berry is available in capsule form, or as an extract or tincture standardized to contain 20% oligomeric procyanidins. Negative side effects are rare, although cases of headache or increased heart rate have been reported in some individuals. It should be noted, however, that the herb should be avoided during pregnancy and should not be combined with other medications intended to treat heart disease. In addition, some research suggests that the action of this herbal remedy may counteract the effects of phenylephrine, an ingredient found in nasal decongestants.