The herb is sometimes used to treat seasonal allergies but researchers from the University of Dundee in Scotland, looking at its efficacy on intermittent allergic rhinitis, otherwise known as hay fever, found it was no more effective than placebo at relieving symptoms.
Hay fever, an allergy to pollen, is the most common form of allergy in the UK, affecting up to 20 per cent of the population. It affects more than 26 million Americans each year and is expected to affect growing numbers as global warming takes hold.
The usual treatment for seasonal allergic rhinitis is antihistamines, which reduce sneezing but are less effective for nasal congestion and may cause sedation and drowsiness. They can also interact with alcohol and decrease driving ability.
An effective herbal alternative could therefore be valuable to the many sufferers of hay fever.
In April this year, the Dundee team reported (Clin Exp Allergy;34(4):646-9) that butterbur was more effective than placebo and as effective as the allergy drug Allegra (fexofenadine) at treating year-round allergic rhinitis.
But comparing the herb to placebo, the researchers failed to find a similar effect, shows the new trial published in July's issue of the Annals of Allergy Asthma Immunology (93(1):56-60).
Thirty-five men and women with seasonal allergies randomly took either butterbur or placebo twice a day for two weeks. Symptoms did not improve significantly in either group and there were also no significant differences in quality of life or nasal air flow.
However bigger studies could be useful to better investigate the herb's efficacy.
Butterbur (Petasites hybridus), is native to Europe, northern Africa, and south western Asia. The leaves and roots of butterbur contain petasines, shown to inhibit leukotrienes, which may be associated with antispasmodic activity and anti-inflammatory action. Extracts of butterbur have been used in bronchial asthma, to smooth muscle spasms, and for headache.