Hawthorn and its effect on the heart

Hawthorn (Crataegus monogyna) is a familiar fruit-bearing shrub that has been used for centuries as a thorny barrier in hedging. In pre-Christian times, goddess-centred worship was performed in sacred groves of hawthorn.

The site of Westminster Abbey was once known as Thorney Island, reputedly after a stand of hawthorns once planted there.

Hawthorn blossom was formerly prominent in May Day celebrations, being cut and fashioned into garlands, but the introduction of the Gregorian calendar in 1752 meant that the trees were seldom in bloom by 1 May, since they tend to flower towards the end of that month.

The blossom was not welcomed inside households, as it was thought it would bring illness and death, its fragrance being compared to the stench of death. In fact, the blossom emits trimethylamine, a chemical that is also produced by rotting corpses.

The shrub has a long history of medicinal use. Since medieval times it has been used to treat diarrhoea and vomiting, and by the 19th century it was being used in Europe as a treatment for cardiovascular conditions.

In recent years much research has been carried out focusing on the apparent beneficial effects of hawthorn extracts on the heart. The flowers, berries and leaves contain many phytochemicals, including crataegic acid, which dilates coronary blood vessels.

Flavonoids extracted from hawthorn have been shown to have antioxidant properties, as well as having a strengthening effect on blood vessel walls by stimulating the cross-linkage of collagen. They also dilate blood vessels and increase intracellular calcium levels.

Procyanidins are thought to inhibit neutrophil elastase, an enzyme that, under conditions of low blood oxygen concentration, is known to damage the heart’s muscular wall.

In Germany the hawthorn has an official monograph, which describes its usefulness in the treatment of heart failure. It reportedly strengthens heart contractions, as well as lowering pulse rate and blood pressure, thus reducing cardiac workload.