Effects of licorice on plasma atrial natriuretic peptide in healthy volunteers.

Ingestion of licorice, 100 g daily for 8 weeks, caused a rise in 81% in plasma atrial natriuretic peptide (ANP) concentration in 12 healthy subjects. Mean body weight increment (1.6 kg) correlated with the increase in plasma ANP (r = 0.59; P less than 0.01). The plasma concentrations of antidiuretic hormone, aldosterone, and plasma renin activity decreased. All these hormonal effects, reflecting retention of sodium and fluid volume, were probably due to the known mineralocorticoid properties of licorice. Blood pressure increased transiently and two subjects developed reversible hypertension. The rise in plasma ANP concentration during ingestion of licorice may be considered a physiological response to prevent fluid retention and development of hypertension.