The flowering tops and berries of the hawthorn (Crataegus) are one of the most beneficial medicinal herbs for circulatory problems.
Hawthorn extracts contain antioxidant flavonoids, such as vitexin, which are used to lower a high blood pressure, relieve angina, improve heart pump efficiency and reduce abnormal heart rhythms as well as reducing stress, anxiety and insomnia. It does not contain cardiac glycosides (such as those found in the foxglove) and therefore has few side effects. Even so, it is a powerful herbal medicine which is best used under the supervision of a medical herbalist – especially if you are taking other prescribed medications.
Hawthorn and blood pressure
Hawthorn is believed to reduce blood pressure by relaxing peripheral blood vessels and dilating arteries in the same way as ACE inhibitor antihypertensive drugs – by blocking the action of ACE (angiotensin-converting enzyme). It may also increase levels of nitric oxide (a powerful blood vessel dilator) and has a mild diuretic action which discourages fluid retention. Its antioxidant action may reduce hardening and furring up of the arteries (atherosclerosis).
In one study, 36 people with ‘mild’ hypertensive had their baseline blood pressure measured at rest, after exercise and after a stressful computer test. The volunteers then took daily supplements for 10 weeks which consisted of either: 600 mg magnesium or 500 mg hawthorn extract, or a combination of both, or an inactive placebo. When their blood pressures were measured again, there were no significant changes after five weeks but, by ten weeks, there were significant reductions in resting diastolic blood pressure in those taking hawthorn extracts compared with the other two groups. They also had lower anxiety scores.
In another study, 79 people with type 2 diabetes, who were taking an average of 4.4 medications to control their glucose levels and blood pressure, were divided into two groups; one group received 1200 mg hawthorn extract while the other took inactive placebo. Those taking hawthorn showed greater reduction in blood pressure (3.6/2.6 mmHg) compared with those taking placebo group (in whom systolic BP fell by 0.8 mmHg but diastolic blood pressure increased by 0.5 mmHg).
Hawthorn and heart failure
A meta-analysis of the results from 10 trials, involving 855 people, show that taking hawthorn extracts reduced heart work load, improved shortness of breath and fatigue, and increased exercise tolerance more than placebo.
Typically 500–1200 mg a day (standardized to at least 1.8 per cent vitexin). However, hawthorn is best taken under the supervision of a medical herbalist. Side effects are uncommon and include nausea, dizziness, sweating and skin rashes.
If your blood pressure is raised, self-monitoring is key to maintaining good control.
Click here for advice on choosing a blood pressure monitor to use at home.
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