Licorice tea is a popular herbal tea consumed in large parts of the Western world. While the concentrations of licorice are low in tea, there have been studies showing that consuming large quantities of licorice may cause a rise in blood pressure. Now, a case report of a man admitted with hypertensive emergency after consumption of licorice tea has been reported in the latest issue of the CMAJ (Canadian Medical Association Journal).
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Dr. Jean-Pierre Falet, Department of Neurology, McGill University, Montréal, Quebec, lead author of the study said that the excessive consumption of herbal products is not always safe: “Excessive amounts of some herbal products can have harmful side effects. Products containing licorice root extract can raise blood pressure, cause water retention and decrease potassium levels if consumed in excess.”
The case report is of an 84-year-old man who visited the hospital emergency department with a dramatic high rise of blood pressure called a hypertensive emergency. His condition was precipitated by consuming large amounts of homemade tea made from licorice root.
He presented with a sudden high rise of blood pressure (between 180 to 200mm persistently over one week) and was suffering from photosensitivity, headaches, chest pain, tiredness and swelling of his lower limbs and calves due to fluid retention. A chest X ray showed a build-up of fluid around his lungs – a condition known as pulmonary edema.
The patient was admitted and his pressure was controlled using medication. He confessed to the treating physicians that he had been drinking 1 to 2 glasses of tea made from homemade licorice root extract called “erk sous” for the past two weeks.
Erk sous is very popular in the Middle East and parts of Europe, especially during Ramadan. Dr. Falet explained, “Given Canada's multicultural population, physicians should consider screening for licorice root intake in patients with difficult-to-control hypertension.
Authors of the study explain that licorice leads to “pseudohyperaldosteronism” or a rise in the hormone aldosterone in the body. This leads to water and sodium retention in the body that causes a secondary rise in blood pressure. They write that aldosteronism can increase sodium levels, blood pressure, and lower blood potassium, metabolic alkalosis etc.
The patient was advised to abstain from erk sous during his stay at the hospital and his blood pressure gradually came down to normal. He was discharged from the hospital after 13 days with a range of other blood pressure lowering medications.
“Licorice, the root of the plant Glycyrrhiza glabra, has been used for thousands of years for its therapeutic properties and as an essential ingredient to various sweets and beverages,” write the authors.
They add that to treat hypertension induced by licorice, supportive measures are necessary to reduce the blood pressure until the effects of the licorice wear off. For persons low on potassium, supplements may be necessary initially.
“Several countries, including the United Kingdom, impose strict rules on product labeling and require a written warning to be printed on products with high concentrations of glycyrrhizin, specifically addressed to patients with hypertension.”
The US Food and Drug Association considers glycyrrhizin safe, if consumed in moderation, and publishes maximum allowable concentrations for various foods.
Health Canada, the regulatory body for food and drugs in Canada, also has an advisory that licorice should not be used if a patient has hypokalemia, high blood pressure, a kidney or cardiovascular disorder, or is taking a medication that might lead to an electrolyte imbalance.”
Approach licorice sweeteners with caution
In a similar study, Jing Li from the Department of Endocrinology and Metabolism and colleagues report a case of hypertensive emergency due to glycyrrhizin (the sweet tasting component of licorice). Their study titled, “Hypertensive crisis with 2 target organ impairment induced by glycyrrhizin,” was published in the March 2018 issue of the journal Medicine (Baltimore).
They report the case of a 47-year-old woman, who took 225 mg of glycyrrhizin daily for 3 years due to primary biliary cholangitis. Licorice or Glycyrrhizin Radix is commonly used as a sweetener. In this case it led to a sudden rise in blood pressure to around 230/110 mmHg. The woman was not a known hypertensive and had never had any blood pressure lowering medications.
She was given blood pressure lowering medications and her pressure was normalized. After around 6 months since she was asked to stopped glycyrrhizin, her blood pressure normalized completely.
Licorice and glycyrrhizin induced hypertension due to pseudo-hyperaldosteronism has been widely reported, yet only 3 cases reported that excessive consumption of licorice could lead to hypertensive emergencies. By presenting this case, we remind clinicians of glycyrrhizin induced hypertension, a condition which could lead to medical emergencies.”
Jing Li, First Author
Hypertensive crisis with 2 target organ impairment induced by glycyrrhizin: A case report. Medicine. (2018). doi.org/10.1097/MD.0000000000010073.
Falet, J-P., Elkrief, A., Green, L. (2019). Hypertensive emergency induced by licorice tea. CMAJ. DOI: doi.org/10.1503/cmaj.180550.