One man’s hot tea habit turned out to be much less relaxing than he hoped, according to his doctors. An 84-year-old Canadian ended up in the emergency department with a serious case of high blood pressure, headache, and chest pain, with the only likely cause of his symptoms being his two weeks straight of drinking homemade liquorice root tea. But it’s hardly the first time liquorice has been blamed for blood pressure problems.
The man’s story was detailed in a case study published Monday in the Canadian Medical Association Journal.
According to the study, the man had long had hypertension and a history of cardiovascular disease, but he had been able to keep his blood pressure in check as recently as his last medical check-up. A week before he visited the hospital, though, he noticed that his blood pressure had began climbing, and nothing he did seemed to help.
By the time doctors saw him, he was already suffering from physical symptoms such as chest pain, fatigue, and headache. And it’s likely things could have gone much worse if he hadn’t gotten help right then and there.
“In his case, the blood pressure was so high that it led to him having heart failure, swelling of the legs, and some abnormalities with his electrolytes, like low potassium,” study author Laurence Green, an internal medicine physician at McGill University Health Centre, told Gizmodo by phone.
There was no apparent reason why his blood pressure had spiralled out of control. But eventually, the man volunteered that he had been drinking one to two glasses of homemade tea brewed from liquorice root for two weeks before his admission to the hospital. Liquorice (derived from the plant Glycyrrhiza glabra) is part of a drink called erk sous, popular in some countries including Egypt and around the Muslim holiday of Ramadan.
Thankfully, once he stopped drinking the liquorice tea and starting taking intensive blood pressure drugs, the man steadily recovered. He left the hospital in good health after two weeks, and a check-up three weeks later found that his blood pressure was back to manageable.
The man’s pre-existing health certainly contributed to the danger he was in. But doctors have long known that liquorice can cause or worsen high blood pressure in people, and as recently as 2017, the Food and Drug Administration warned that people over the age of 40 should avoid eating too much liquorice candy.
According to the agency, eating more than two ounces of black liquorice candy a day for two weeks straight can raise the risk of developing an irregular heart rhythm or arrhythmia in older people.
“This is not a new discovery,” Green noted. “It’s more of an episodic reminder to doctors that liquorice can cause these symptoms and that they should be aware of that.”
The culprit behind liquorice’s affect on blood pressure is the compound that gives it its slightly sweet taste, called glycyrrhizin (or glycyrrhizinic acid). In high enough doses, it causes our cells to retain more water than they should and our body’s potassium levels to plummet, the net result of which drives up blood pressure. According to his doctors, the man did know about the risks of liquorice and high-blood pressure, but he simply didn’t suspect the tea when his symptoms first arose.
While the case study is intended for doctors, Green said that there are things the public should keep in mind as well, particularly those of us who love their red Twizzlers.
“Many people think they’re eating liquorice, but they’re probably not. That red candy that’s sort of shaped like liquorice? There’s no liquorice in there whatsoever. It has to be the black liquorice. And even then, if it’s taken in moderation, and you don’t have high blood pressure or heart problems, you should be fine,” Green said.
It is theoretically possible for perfectly healthy people to develop liquorice related high blood pressure or other related problems, he added, but it would take some pretty huge quantities of liquorice to pull off. So as long as you don’t do that, you’re in the clear. After all, of the ways to go, death by liquorice binge might be one of the most embarrassing.