Liquorice in moderate doses decreases serum levels of vitamin B12 but does not affect the serum lipid levels
Helga Sigurjonsdottir1, Margret Arnadottir2 & Sven Wallerstedt3
Background: Liquorice in moderate doses increases blood pressure (BP) in healthy individuals (NT) as well as patients with hypertension (HT) due to increased cortisol effect. Glycyrrhetinic acid, the active substance in liquorice, inhibits 11beta-hydroxysteroid-dehydrogenase type 2 (11betaHSD2) which converts the active hormone cortisol to the inactive hormone cortisone. Recently it has been reported that treatment with glucocorticoids decreases serum levels of cobalamin (B12), it is also known that increased cortisol levels negatively affect different metabolic risk-factors as serum lipids. Hence, it is possible that liquorice due to its increased cortisol effect can decrease serum levels of B12 and affect the lipid levels negatively.
Methods: Thirty-six individuals, 25 NT (13 men and 12 women) and 11 HT (8 men and 3 women), 2244 years old, consumed 100 g of liquorice (150 mg GA) daily for 4 weeks. Blood tests were taken, 24-hour-urin collected and BP measured before and after the liquorice consumption. The study was approved by the local ethical committee.
Results: Serum-B12 decreased from 299±78 pmol/L to 284±78 pmol/L in the whole group (n=36, P=0.005), from 322±77 pmol/L to 303±74 pmol/L (P=0.005) in the NT group and from 288±82 pmol/L to 270±77 pmol/L (P=0.007) in men. Serum levels for total-cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, apolipoprotein A1 and lipoprotein(a) did not change after liquorice consumption. Serum levels for apolipoprotein B (ApoB) decreased from 0.83±0.22 g/L to 0.81±0.22 g/L (P=0.04) in the whole group (n=36). The ratio for urinary free cortisol/cortisone (Q, an indicator of 11betaHSD2-activity) increased significantly in all groups (P<0.001 in all groups). No statistical difference was found between the genders or between the NT-and HT-groups.
Conclusion: The glucocorticoid-effect induced by liquorice consumption in moderate doses for 4 weeks is sufficient to significantly decrease the serum concentration of B12, which is a novel finding. Even if the decrease is not substantial it can be of clinical importance. This moderate dose of liquorice does not affect the serum lipid levels.