title: Liquorice-induced rise in blood pressure: a linear dose-response relationship.
abstract: To clarify the dose-response and the time-response relationship between liquorice consumption and rise in blood pressure and explore the inter-individual variance this intervention study was designed and executed in research laboratories at University hospitals in Iceland and Sweden. Healthy, Caucasian volunteers who also served as a control for himself/herself consumed liquorice in various doses, 50-200 g/day, for 2-4 weeks, corresponding to a daily intake of 75-540 mg glycyrrhetinic acid, the active substance in liquorice. Blood pressure was measured before, during and after liquorice consumption. Systolic blood pressure increased by 3.1-14.4 mm Hg (P < 0.05 for all), demonstrating a dose-response but not a time-response relationship. The individual response to liquorice followed the normal distribution. Since liquorice raised the blood pressure with a linear dose-response relationship, even doses as low as 50 g of liquorice (75 mg glycyrrhetinic acid) consumed daily for 2 weeks can cause a significant rise in blood pressure. The finding of a maximal effect of liquorice after only 2 weeks has important implications for all doctors dealing with hypertension. There does not seem to be a special group of responders since the degree of individual response to liquorice consumption followed the normal distribution curve.
authors.affiliation: Department of Medicine, Sahlgrenska University Hospital/Ostra, Gröna Stråket 8, 413 45 Göteborg, Sweden.
authors.lastname: Sigurjónsdóttir HA
authors.forename: L
authors.initials: L
authors.lastname: Franzson
authors.forename: K
authors.initials: K
authors.lastname: Manhem
authors.forename: J
authors.initials: J
authors.lastname: Ragnarsson
authors.forename: G
authors.initials: G
authors.lastname: Sigurdsson
authors.forename: S
authors.initials: S
authors.lastname: Wallerstedt
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001794:Blood Pressure / Q000187:drug effects*; D016001:Confidence Intervals; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006035:Glycyrrhiza / Q000009:adverse effects*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000139:chemically induced*; D007055:Iceland; D008297:Male; D010946:Plants, Medicinal; D011188:Potassium / Q000097:blood; D012016:Reference Values; D012044:Regression Analysis; D013548:Sweden; D013997:Time Factors
chemical_list: D011188:Potassium