Antiatherosclerotic effects of licorice extract supplementation on hypercholesterolemic patients: Decreased CIMT, reduced plasma lipid levels, and decreased blood pressure

Background: Ethanolic extract of licorice root has been shown to reduce low-density lipoprotein (LDL) oxidation in atherosclerotic mice and in both hypercholesterolemic and normal lipidemic humans. Objective: This study examined the effect of licorice-root extract on carotid intima-media thickness (CIMT) in individuals with hypercholesterolemia. Design: Individuals with hypercholesterolemia (total cholesterol ]6.18 mmol/L [240 mg/dL]) and without significant stenosis were randomly allocated to two groups: an experimental group that consumed 0.2 g/day of ethanolic extract of licorice root for 12 months, and a control group that received a placebo. Results: Of 110 eligible participants, 94 (4180 years old) completed the study. A significant CIMT decrease from 0.9290.25 mm to 0.8490.21 mm was observed in the experimental group compared with an increase from 0.8590.17 mm to 0.8890.19 mm in the control group. Mean plasma total cholesterol levels and LDL cholesterol decreased, at the range baseline to 1 year, from 284932 mg/dl to 262925 mg/dl and from 18398.5 mg/dl to 17499.1 mg/dl, respectively, for the experimental group (pB0.001) and from 291935 to 289931 mg/dl and from 177.6910.7 to 179.399.6 (p0.08), respectively, for the control group. Mean high-density lipoprotein (HDL) did not change significantly in either group. In the experimental group, systolic blood pressure decreased from 138912 mmHg to 125913 mmHg after 1 year (p0.01) and increased from 136915 mmHg to 137913 mmHg in the control group. Diastolic blood pressure decreased from 9299 mmHg to 84910 mmHg (p0.01) in the experimental group and increased from 89911 mmHg to 9098 mmHg in the control group. Conclusion: Following 1 year of licorice consumption, mean CIMT, total cholesterol, LDL levels, and blood pressure were decreased. This suggests that licorice may attenuate the development of atherosclerosis and of related cardiovascular diseases.