Liquorice, derived from Glycyrrhiza species, is used worldwide in foods and traditional remedies and contains multiple bioactive compounds. The principal compound glycyrrhizic acid is associated with raised blood pressure. Another liquorice constituent, the isoflavonoid glabridin, has been reported in preclinical studies to have antioxidant, anti-inflammatory, and glucose-lowering properties and may affect lipid oxidation and bone-related hormones.
The clinical question addressed here is whether a short-term, dietary dose of whole liquorice—at an intake previously shown to raise systolic blood pressure—affects markers of dysglycemia, blood lipids, systemic inflammation, or calcium metabolism in healthy young adults. The authors also quantified the glabridin content of the administered liquorice pastilles using liquid chromatography-tandem mass spectrometry (LC-MSMS).
This report is a secondary analysis of a previously described randomized, non-blinded 2-treatment, 2-period, 2-sequence (2x2) crossover trial. Twenty-eight volunteers aged 18–30 years were recruited in Östergötland County, Sweden, between January and April 2023. Key exclusion criteria included known kidney, liver, or endocrine disease and treatment with hormones (oral contraceptives were excluded; intrauterine devices were allowed).
Participants completed a run-in period and were then randomized by drawing ballots to alternate between the liquorice and control products across two 2-week periods separated by 2-week washouts.
Intervention: Liquorice pastilles produced from Glycyrrhiza glabra (manufacturer-reported 4% sugars). Participants were instructed to consume 3.3 g of these liquorice pastilles daily during the intervention period.
Control: Sugar-free salty liquorice-flavoured confectionaries without declared raw liquorice content. Participants consumed 2.9 g of control product daily during the control period. Reported energy contents of the two products were similar.
Baseline measures included height, weight, and questionnaire data (age, sex, tobacco and alcohol use, physical activity). Participants were asked to avoid liquorice for at least 4 weeks before inclusion.
Blood samples were collected at baseline and at the end of each period between 08:00 and 09:00 after an overnight fast, with participants seated and rested for at least 5 minutes. Measured biomarkers included:
Analytical methods were performed at an ISO/IEC 17025-accredited clinical laboratory using established platforms: enzymatic photometric methods for glucose and lipids, electrochemiluminescence immunoassay (ECLIA) for insulin and PTH, immunoturbidimetric photometry for hsCRP, and ion-selective electrode potentiometry for ionized calcium.
The liquorice pastilles administered in the study were analyzed using liquid chromatography-tandem mass spectrometry (LC-MSMS). The measured glabridin content was 0.25 ± 0.14 µg per mg of product.
Normality was assessed with the Shapiro–Wilk test. Continuous variables are reported as mean ± standard deviation and between-group differences were tested using the Wilcoxon rank-sum test where appropriate. Paired comparisons between run-in and each study period were tested using paired t tests for normally distributed variables and paired Wilcoxon signed-rank tests for skewed variables. Categorical variables were compared using Chi-squared tests.
The provided source excerpt does not include full statistical tables, the complete list of adjusted analyses, or additional modeling details; those details were not reported in the text supplied.
Glabridin content: 0.25 ± 0.14 µg glabridin per mg of liquorice pastille as determined by LC-MSMS.
Metabolic markers: No statistically significant effects of liquorice intake versus control were observed on HbA1c, fasting plasma glucose, insulin, lipid profile (including LDL), ionized calcium, or plasma PTH in this short-term intervention.
Inflammation (hsCRP): The change in hsCRP differed between periods. During the liquorice intervention, hsCRP increased by 32.5% (95% CI −9.7 to 74.6). During the control period hsCRP increased by 311.5% (95% CI −40.8 to 663.7). The between-period difference reached statistical significance (P = 0.045), interpreted by the authors as liquorice intake attenuating the rise in hsCRP relative to control.
The study found measurable amounts of glabridin in the liquorice pastilles used and observed no short-term improvements in glycemic control or lipid markers at the examined dose. The statistically significant between-period difference in hsCRP suggests an attenuation of inflammatory marker rise with liquorice intake compared with control, although absolute changes and clinical significance require cautious interpretation given wide confidence intervals and short follow-up.
The authors note prior evidence that the glycyrrhizic acid content in an equivalent whole-liquorice dose (100 mg) raises systolic blood pressure by 3.1 mmHg. Against that background, they conclude that any potential metabolic or anti-inflammatory effects attributable to glabridin found in whole liquorice are unlikely to outweigh the hypertensive risk associated with glycyrrhizic acid when consumed as whole liquorice products.
These additional methodological and numerical details were not reported in the source text provided here.
In this randomized crossover sample of healthy young adults, 3.3 g daily intake of whole liquorice pastilles—containing measurable glabridin—did not improve markers of dysglycemia, blood lipids, or calcium metabolism during short-term exposure. Liquorice intake was associated with an attenuation of hsCRP elevation compared with a control confectionary, but the authors conclude that any potential metabolic or anti-inflammatory benefits of glabridin in whole liquorice are unlikely to counterbalance the known hypertensive effects of glycyrrhizic acid in whole liquorice products. Further details and longer-term data were not included in the provided excerpt.