Summary
Licorice (Glycyrrhiza plants, usually the Glabra species) have been used in Traditional Chinese Medicine to fairly good acclaim for various digestive and health problems, and as a general vitality promoting agent. Licorice is also routinely used as a candy product, and is inherently a functional food rather than just a candy (as the oil containing the traditional licorice flavor also contains some bioactive compounds).
One of the most important compounds in Licorice appears to be Glycyrrhizin, which is the sugar-bound form of Glycyrrhetic Acid (there exists both an alpha and beta isomer, with the latter 18β-Hydroxyglycyrrhetic acid being referred to frequently). This compound is highly relevant when consuming pure licorice extracts due to its good absorption and relatively high content, but also underlies a fairly reliable reduction in testosterone and a highly reliable increase in circulating cortisol after consumption. Both of these effects are dose-dependent and not associated with any toxicological effects (and reversed upon cessation of Licorice), but many persons may want to avoid Glycyrrhizin and Glycyrrhetic Acid due to these reasons.
An ethanolic extract of Licorice, sometimes used in supplements, is able to concentrate flavanoids and isoflavanoid compounds with a relatively low Glycyrrhizin content. Some of these flavanoids, including Glabridol as well as the Liquirtigenin class of flavanoids, appear to be the ones that exert properties that would be seen as 'beneficial'.
What are other names for Licorice
- Licorice
- Liquorice
- Yashtimadhu
- Glycyrrhiza
- Glycyrrhiza Uralensis
- Glycyrrhiza Glabra
Dosage information
Prior to supplementing Licorice, please be aware of Glycyrrhizin (the agent that increases cortisol and reduces testosterone) and, if these results are not desired, try to get products with low Glycyrrhizin content (less than 500mg total dose daily). 150mg has been confirmed to not influence these hormones
Traditional Chinese Medicine recommends a decoction of 8-15g Licorice for health protection and up to 100g for disease states. Consumption of licorice in these doses as a food product does confer the same properties as supplementation, but the caloric and carbohydrate intake from either the root of confectionaries derived from the root need to be accounted for.
With supplementation, intakes of Licorice in the range of 150-300mg daily appear to be most commonly used and intakes of Deglyccyrhizinated (without Glycyrrhizin) up to 1800mg daily for 4 weeks are not associated with toxicity in humans.
Examine Database: Licorice
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In this randomized controlled trial, daily consumption of black licorice candy increased systolic blood pressure. This study used true black licorice containing glycyrrhizic acid, which is not widely available in the United States.
Research Breakdown
Examine Database References
- Cortisol - Sigurjonsdottir HA, Manhem K, Axelson M, Wallerstedt SSubjects with essential hypertension are more sensitive to the inhibition of 11 beta-HSD by liquoriceJ Hum Hypertens.(2003 Feb)
- Estrogen - Helga Agusta Sigurjonsdottir, Magnus Axelson, Gudmundur Johannsson, Karin Manhem, Ernst Nystrom, Sven WallerstedtLiquorice in moderate doses does not affect sex steroid hormones of biological importance although the effect differs between the gendersHorm Res.(2006)
- Body Fat - Bell ZW, Canale RE, Bloomer RJA dual investigation of the effect of dietary supplementation with licorice flavonoid oil on anthropometric and biochemical markers of health and adiposityLipids Health Dis.(2011 Feb 10)
- Testosterone - Armanini D, Bonanni G, Mattarello MJ, Fiore C, Sartorato P, Palermo MLicorice consumption and serum testosterone in healthy manExp Clin Endocrinol Diabetes.(2003 Sep)
- Cortisol - Al-Dujaili EA, Kenyon CJ, Nicol MR, Mason JILiquorice and glycyrrhetinic acid increase DHEA and deoxycorticosterone levels in vivo and in vitro by inhibiting adrenal SULT2A1 activityMol Cell Endocrinol.(2011 Apr 10)
- Testosterone - R A Josephs, J S Guinn, M L Harper, F AskariLiquorice consumption and salivary testosterone concentrationsLancet.(2001 Nov 10)
- Testosterone - Armanini D, Bonanni G, Palermo MReduction of serum testosterone in men by licoriceN Engl J Med.(1999 Oct 7)
- Testosterone - Mee Jung Mattarello, Stefano Benedini, Cristina Fiore, Valentina Camozzi, Paola Sartorato, Giovanni Luisetto, Decio ArmaniniEffect of licorice on PTH levels in healthy womenSteroids.(2006 May)
- LDL Oxidation - Carmeli E, Fogelman YAntioxidant effect of polyphenolic glabridin on LDL oxidationToxicol Ind Health.(2009 May-Jun)
- Canker Sores Symptoms - Martin MD, Sherman J, van der Ven P, Burgess JA controlled trial of a dissolving oral patch concerning glycyrrhiza (licorice) herbal extract for the treatment of aphthous ulcersGen Dent.(2008 Mar-Apr)
- Luteinizing Hormone - Decio Armanini, Mee Jung Mattarello, Cristina Fiore, Guglielmo Bonanni, Carla Scaroni, Paola Sartorato, Mario PalermoLicorice reduces serum testosterone in healthy womenSteroids.(Oct-Nov 2004)
- Oxidative Stress Biomarkers - B Fuhrman, S Buch, J Vaya, P A Belinky, R Coleman, T Hayek, M AviramLicorice extract and its major polyphenol glabridin protect low-density lipoprotein against lipid peroxidation: in vitro and ex vivo studies in humans and in atherosclerotic apolipoprotein E-deficient miceAm J Clin Nutr.(1997 Aug)