Urtica dioica (stinging nettle)
This article was written by Eric Yarnell, ND, RH(AHG) and is protected by copyright, 2020.
Diuretics vs. Aquaretic
Like diuretic drugs, many herbs traditionally used as diuretics have been shown to act in the kidney to alter electrolyte handing (Clare 2009; Hooman 2009; Herrera-Arellano 2004; Andallu 2000; Lemus 1996; Srividya 1995). Unlike most diuretic drugs, however, most and possibly all these herbs are also aquaretic (Ekpenyong 2016). They appear to dilate the afferent glomerular arteriole, thus driving more blood into the glomerulus and increasing glomerular filtration rate.
This distinction is important because, unlike diuretic drugs, herbs could be a problem in late chronic kidney disease (CKD). When enough nephrons have failed, pushing the remaining few to work harder is not likely to lead to good outcomes. While this has not really been tested, clinically I have found that these herbs are associated with progression of late-stage CKD, and only very rarely improvement. Unfortunately, many well-meaning practitioners prescribe these herbs to people with late-stage CKD because they are "kidney herbs," a practically meaningless phrase suggesting they could help all kidney problems, but which is not true. Diuretic/aquaretic herbs are not the same as nephroprotective herbs, a completely different class of herb that do help people with CKD (Yarnell 2012). Additionally, while diuretic drugs are commonly used in late-stage CKD because of the common occurrence of edema, the urge to use these drugs should be avoided or only in moderation and with careful monitoring for worsening kidney function.
This distinction is important because, unlike diuretic drugs, herbs could be a problem in late chronic kidney disease (CKD). When enough nephrons have failed, pushing the remaining few to work harder is not likely to lead to good outcomes. While this has not really been tested, clinically I have found that these herbs are associated with progression of late-stage CKD, and only very rarely improvement. Unfortunately, many well-meaning practitioners prescribe these herbs to people with late-stage CKD because they are "kidney herbs," a practically meaningless phrase suggesting they could help all kidney problems, but which is not true. Diuretic/aquaretic herbs are not the same as nephroprotective herbs, a completely different class of herb that do help people with CKD (Yarnell 2012). Additionally, while diuretic drugs are commonly used in late-stage CKD because of the common occurrence of edema, the urge to use these drugs should be avoided or only in moderation and with careful monitoring for worsening kidney function.
Herbs vs. Drugs
Diuretic/aquaretic herbs have many benefits, and clinical trials showing them helping people with hypertension and congestive heart failure is further evidence they have to have diuretic activity (Herrera-Arellano 2004; Kirchhoff 1983).
Diuretics herbs differ from diuretic drugs in several other important aspects. The most common diuretic drugs (thiazides and loop diuretics) cause potassium (generally only at higher than usual clinical doses) and magnesium wasting (Odvina 2006; Hattori 1988). There is growing evidence that long-term thiazide use significantly increases the risk of insulin resistance and diabetes mellitus type 2 (Ong 2014; Carter 2008). This is generally considered an acceptable risk given the consistent reduction in total mortality in people with hypertension who take thiazides (Anonymous 2014). Anyhow, diuretic herbs carry none of these risks, in part because they actually contain potassium and magnesium. As just one example, Urtica dioica (nettle) leaf, an established diuretic herb, actually helps lower fasting blood glucose in patients with type 2 diabetes (Ziaei 2020).
Overall there is a surprising dearth of research in the field of diuretic herbs. This is particularly unfortunate given how accurate it appears that the ancient text De Materia Medica by Dioscorides was in identifying diuretic herbs (Yarnell 2019).
Diuretics herbs differ from diuretic drugs in several other important aspects. The most common diuretic drugs (thiazides and loop diuretics) cause potassium (generally only at higher than usual clinical doses) and magnesium wasting (Odvina 2006; Hattori 1988). There is growing evidence that long-term thiazide use significantly increases the risk of insulin resistance and diabetes mellitus type 2 (Ong 2014; Carter 2008). This is generally considered an acceptable risk given the consistent reduction in total mortality in people with hypertension who take thiazides (Anonymous 2014). Anyhow, diuretic herbs carry none of these risks, in part because they actually contain potassium and magnesium. As just one example, Urtica dioica (nettle) leaf, an established diuretic herb, actually helps lower fasting blood glucose in patients with type 2 diabetes (Ziaei 2020).
Overall there is a surprising dearth of research in the field of diuretic herbs. This is particularly unfortunate given how accurate it appears that the ancient text De Materia Medica by Dioscorides was in identifying diuretic herbs (Yarnell 2019).
References
Andallu B, Radhika B (2000) "Hypoglycemic, diuretic and hypocholesterolemic effect of winter cherry (Withania somnifera, Dunal) root" Indian J Exp Biol 38(6):607–9.
Anonymous (2014) "Treating essential hypertension. The first choice is usually a thiazide diuretic" Prescrire Int 23(152):215–20.
Clare BA, Conroy RS, Spelman K (2009) “The diuretic effect in human subjects of an extract of Taraxacum officinale folium over a single day” J Altern Complement Med 15(8):929–34.
Carter BL, Einhorn PT, Brands M, et al. (2008) "Thiazide-induced dysglycemia: Call for research from a working group from the National Heart, Lung, and Blood Institute" Hypertension 52(1):30–6.
Ekpenyong CE, Daniel NE, Antai AB (2015) "Effect of lemongrass tea consumption on estimated glomerular filtration rate and creatinine clearance rate" J Ren Nutr 25(1):57–66.
Ellison DH, Loffing J (2009) "Thiazide effects and adverse effects: Insights from molecular genetics" Hypertension 54(2):196–202.
Hattori K, Saito K, Sano H, Fukuzaki H (1988) "Intracellular magnesium deficiency and effect of oral magnesium on blood pressure and red cell sodium transport in diuretic-treated hypertensive patients" Jpn Circ J 52(11):1249–56.
Herrera-Arellano A, Flores-Romero S, Chávez-Soto MA, Tortoriello J (2004) "Effectiveness and tolerability of a standardized extract from Hibiscus sabdariffa in patients with mild to moderate hypertension: A controlled and randomized clinical trial" Phytomedicine 11(5):375–82.
Hooman N, Mojab F, Nickavar B, Pouryousefi-Kermani P (2009) "Diuretic effect of powdered Cerasus avium (cherry) tails on healthy volunteers" Pak J Pharm Sci 22(4):381–3.
Kirchhoff HW (1983) "Nettle juice as a diuretic" Z Phytother 4:621–626 [in German].
Lemus I, García R, Erazo S, et al. (1996) "Diuretic activity of an Equisetum bogotense tea (platero herb): Evaluation in healthy volunteers" J Ethnopharmacol 54(1):55–8.
Odvina CV, Mason RP, Pak CY (2006) "Prevention of thiazide-induced hypokalemia without magnesium depletion by potassium-magnesium-citrate" Am J Ther 13(2):101–8.
Ong KL, Barter PJ, Waters DD (2014) "Cardiovascular drugs that increase the risk of new-onset diabetes" Am Heart J 167(4):421–8.
Srividya N, Periwal S (1995) "Diuretic, hypotensive and hypoglycaemic effect of Phyllanthus amarus" Indian J Exp Biol 33(11):861–4.
Yarnell EL (2012) "Botanical medicines used for kidney disease in the United States" Iran J Kidney Dis 6(6):407–18.
Yarnell E, Touwaide A (2019) "Accuracy of Dioscorides,' De materia medica (first century C.E.), regarding diuretic activity of plants" J Altern Complement Med 25(1):107–20.
Ziaei R, Foshati S, Hadi A, et al. (2020) "The effect of nettle (Urtica dioica) supplementation on the glycemic control of patients with type 2 diabetes mellitus: A systematic review and meta-analysis" Phytother Res 34(2):282–94.
Anonymous (2014) "Treating essential hypertension. The first choice is usually a thiazide diuretic" Prescrire Int 23(152):215–20.
Clare BA, Conroy RS, Spelman K (2009) “The diuretic effect in human subjects of an extract of Taraxacum officinale folium over a single day” J Altern Complement Med 15(8):929–34.
Carter BL, Einhorn PT, Brands M, et al. (2008) "Thiazide-induced dysglycemia: Call for research from a working group from the National Heart, Lung, and Blood Institute" Hypertension 52(1):30–6.
Ekpenyong CE, Daniel NE, Antai AB (2015) "Effect of lemongrass tea consumption on estimated glomerular filtration rate and creatinine clearance rate" J Ren Nutr 25(1):57–66.
Ellison DH, Loffing J (2009) "Thiazide effects and adverse effects: Insights from molecular genetics" Hypertension 54(2):196–202.
Hattori K, Saito K, Sano H, Fukuzaki H (1988) "Intracellular magnesium deficiency and effect of oral magnesium on blood pressure and red cell sodium transport in diuretic-treated hypertensive patients" Jpn Circ J 52(11):1249–56.
Herrera-Arellano A, Flores-Romero S, Chávez-Soto MA, Tortoriello J (2004) "Effectiveness and tolerability of a standardized extract from Hibiscus sabdariffa in patients with mild to moderate hypertension: A controlled and randomized clinical trial" Phytomedicine 11(5):375–82.
Hooman N, Mojab F, Nickavar B, Pouryousefi-Kermani P (2009) "Diuretic effect of powdered Cerasus avium (cherry) tails on healthy volunteers" Pak J Pharm Sci 22(4):381–3.
Kirchhoff HW (1983) "Nettle juice as a diuretic" Z Phytother 4:621–626 [in German].
Lemus I, García R, Erazo S, et al. (1996) "Diuretic activity of an Equisetum bogotense tea (platero herb): Evaluation in healthy volunteers" J Ethnopharmacol 54(1):55–8.
Odvina CV, Mason RP, Pak CY (2006) "Prevention of thiazide-induced hypokalemia without magnesium depletion by potassium-magnesium-citrate" Am J Ther 13(2):101–8.
Ong KL, Barter PJ, Waters DD (2014) "Cardiovascular drugs that increase the risk of new-onset diabetes" Am Heart J 167(4):421–8.
Srividya N, Periwal S (1995) "Diuretic, hypotensive and hypoglycaemic effect of Phyllanthus amarus" Indian J Exp Biol 33(11):861–4.
Yarnell EL (2012) "Botanical medicines used for kidney disease in the United States" Iran J Kidney Dis 6(6):407–18.
Yarnell E, Touwaide A (2019) "Accuracy of Dioscorides,' De materia medica (first century C.E.), regarding diuretic activity of plants" J Altern Complement Med 25(1):107–20.
Ziaei R, Foshati S, Hadi A, et al. (2020) "The effect of nettle (Urtica dioica) supplementation on the glycemic control of patients with type 2 diabetes mellitus: A systematic review and meta-analysis" Phytother Res 34(2):282–94.