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

Astragalus – A Herb to Watch

Article and Photo © Ann Walker

The root of Astragalus membranaceus has been used in traditional Chinese medicine for centuries. The many laboratory studies carried out so far show that the herb has immune modulating (or modifying) and anti-inflammatory effects (PMID: 26916911). These properties account for the herb’s traditional applications for fatigue of all types, allergies and infections, but its use as an adjunct to chemotherapy to reduce their side effects is a more recent development. But what is the evidence for benefit for those undergoing chemotherapy? There is promising clinical-trial evidence, but it is sparse because most of the studies have been small and of poor quality.

Lack of clinical data is surprising considering the huge amount of laboratory research that has gone into studying this herb and its constituents, but cancer is difficult to study in a clinical trial setting because of ethical considerations. A review by the internationally-recognised Cochrane review collaboration found four trials in which Astragalus was combined with chemotherapy for large bowel cancer (PMID: 15674951).

These showed reduced nausea during chemotherapy and better preservation of the white blood cell count, but it again concluded that more vigorous trials were needed to confirm these results. However, there was no evidence of any harm from including Astragalus in these regimes. While waiting for more evidence of its adjunct value in chemotherapy, Astragalus has been adopted as a key herb in western herbal medicine over the last decade because of the research interest in it. I use it a lot in my clinic, along with other herbs, for reducing susceptibility to infection – both viral and bacterial - and to reduce the symptoms of chemotherapy treatment.

PMID = PubMed identifier

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