¹Department of Medicine, Sahlgrenska University Hospital/Östra, Göteborg, Sweden

²Department of Chemical Pathology, Reykjavik City Hospital, University of Iceland, Iceland

³Department of Medicine, Reykjavik City Hospital, University of Iceland, Iceland

Correspondence to: Dr H Á Sigurjónsdóttir, Department of Endocrinology, Gröna Stråket 8, Sahlgrenska University Hospital/ Sahlgrenska, 413 45 Göteborg, Sweden, Fax: +46 31 821524

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.

Journal of Human Hypertension (2001) 15, 549-552

11 -hydroxysteroid dehydrogenase; liquorice; glycyrrhetinic acid