Toronto, May 28 (IANS): Herbal products can have harmful side effects too, says a study, published in the Canadian Medical Association Journal. It was corroborate by an incident in Canada when a man landed up in a hospital for high-blood pressure emergency after over-consuming homemade tea made from licorice root.

"Excessive amounts of some herbal products can have harmful side effects," said Jean-Pierre Falet from McGill University in Canada. And products containing licorice root extract can raise blood pressure leading to headache and chest pain.

"Products containing licorice root extract can raise blood pressure, cause water retention and decrease potassium levels if consumed in excess," Falet said.

The high blood pressure in the 84-year-old resident of Canada was found to be induced by homemade tea made from licorice root, according to the researchers. His blood pressure was severely elevated, and he was suffering from a headache, light sensitivity, chest pain, fatigue and fluid retention in the calves, said the study.

After admission to hospital and treatment, the patient, who had a history of high blood pressure, told physicians he had been daily drinking 1-2 glasses of homemade licorice root extract called "erk sous" for the past two weeks.

Licorice tea is popular in the Middle East and parts of Europe, and erk sous is especially popular in Egypt during Ramadan.

The findings suggest that physicians should consider screening for licorice root intake in patients with difficult-to-control hypertension.