Friday, 10 January 2020

Diuretic Effect of Dandelion

Article & Photo © Ann Walker

Dandelion leaf is used in traditional western herbal medicine as a diuretic for reducing fluid retention. Indeed its French name of pis-en-lit (piss the bed) is testament to this. Herbal practitioners find the herb useful these days for reducing oedema, for example helping patients to reduce ankle oedema on long-haul flights or for premenstrual ‘heavy-legs’. But what scientific evidence is there for this effect? A search the world’s medical literature (PubMed) shows that there was, indeed, a study of Dandelion’s diuretic effect published by American researchers in 2009 (PMID: 19678785).

It was only a small pilot study, carried out over a single day using an aqueous-alcoholic extract of fresh dandelion leaf (using a dose of 8 ml three times in the day) on 17 people. It was not a blinded or controlled study, so it will not satisfy the ‘gold standard’ criteria for drug research, but nevertheless it does provide the first documented evidence of the diuretic effect of dandelion in a group of humans. In the study, the excretion ratio (urine volume-to-fluid intake) was found to have increased for all subjects in the 5-hour period following the second dose of the extract, indicating a diuretic effect.

The precise mechanism, or indeed even the active constituents, responsible for the diuretic effect of dandelion are not known. There are some unique compounds with long names in the plant: viz. eudesmanolide and germacranolide, but there are also others such as taraxasterol, which, no doubt, also contribute to its physiological effects. Apart from diuresis, these effects include, liver stimulant (laxative), anti-inflammatory, anti-oxidant, anti-carcinogenic, pain killing, blood-glucose modulating, and blood-thinning properties.

There is increasing laboratory research evidence for these effects, but sadly, no human trials for a variety of traditional applications of the herb including: liver and gallbladder problems, breast diseases, digestive problems, joint pain, fever and skin diseases. There is plenty of scope here for many PhD topics in the future, if someone comes up with the funding

PMID = PubMed identifier

Ann Walker PhD, FCPP, MNIMH, RNutr
Course Director DHM
Herbal Practitioner