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Liquorice: "Natural", but not always harmless

The 51-year-old man presented in hospital complaining of abdominal pain, vomiting and diarrhea. On initial investigation he was found to have very high blood pressure and low blood levels of potassium. At first the doctors could not figure out what was happening but on questioning the patient revealed that he had recently started eating about fifty licorice flavoured jelly beans a day, a practice he continued even in the hospital.

The 51-year-old man presented in hospital complaining of abdominal pain, vomiting and diarrhea. On initial investigation he was found to have very high blood pressure and low blood levels of potassium. At first the doctors could not figure out what was happening but on questioning the patient revealed that he had recently started eating about fifty licorice flavoured jelly beans a day, a practice he continued even in the hospital. Suddenly the mystery was solved! Licorice is well known to raise blood pressure and to lower potassium. After stopping the jelly beans the patient recovered uneventfully. A more detailed examination of licorice seem to be in order since this is certainly not the first time someone experienced the licorice effect.

Many consider “The Gold Rush” to be Charlie Chaplin’s greatest movie.  Probably because of the hilarious shoe-eating scene. In this 1925 epic the Little Tramp travels to the Klondike searching for gold and finds a heap of trouble instead.  He gets trapped in a cabin by a blizzard and soon runs out of food. What can he do but boil his shoe? And soon, with great satisfaction, he is dining on the sole as if it were a piece of steak. I mean really dining, not just pretending. How did Chaplin do this?  Simple. The special prop was made by the American Licorice company and undoubtedly was far more tasty than shoe leather. I’m sure Chaplin never considered the possible health consequences of his meal. But it is an interesting consideration.

Bring up the subject of licorice, and most peoples’ thoughts may indeed turn to the movies. It is not Chaplin’s culinary escapades they think of though, it is the red or black stringy stuff that competes with popcorn in virtually every theatre lobby. Actually the red version has nothing to do with licorice and the black strings offer only a very tenuous connection. Licorice is a plant with a long and fascinating history.  Four thousand-year-old Egyptian hieroglyphics describe its use as a medicine and the ancient Greeks were known to have used the plant’s roots as a sweetening agent. Indeed, our word licorice evolved from the Greek word glykyrrhiza, meaning sweet root. Nobody knows who first had the bright idea of boiling the root in water and then heating the resulting solution until the water evaporated to produce the familiar black mass we call licorice.  But it was probably an attempt to produce a medicinal substance. After all, botanical history is filled with human attempts to capitalize on the potential curative properties of natural substances. And the properties of licorice root certainly would have suggested experimentation. Various ancient manuscripts had described the use of the root in the treatment of coughs and digestive problems.

Licorice is one of the most widely investigated plant products. Modern chemistry has allowed for the isolation, separation and characterization of dozens of different compounds found in the root extract. No single component accounts for the characteristic flavor, but anethole comes close. This compound is also found in the anise plant, from which it can be extracted, or it can be synthesized in the laboratory. Anethole is commonly used to impart a licorice flavor to candies, as in the case of the black stringy concoction. That’s why characterizing this as licorice is misleading. Even when it is made with real licorice extract, the concentration of licorice compounds is very low. This is important to know because it means that neither the problems nor the potential therapeutic effects that are attributed to real licorice apply to the twists we chew on in movie theatres. Real licorice twists do exist though, mostly in Europe.

What problems and what therapeutic effects, you ask? Let’s start with the concerns. Like the calamity that befell a twenty-year-old lady who had to be admitted to a hospital because she had lost all strength in the bottom half of her body.  Blood tests quickly revealed an extremely low potassium level. An astute physician immediately asked about her dietary habits and discovered that the young lady was virtually addicted to licorice candies. She had been eating up to half a pound a day! Right then and there the problem was solved. The most prevalent compound in licorice, and the most studied, is glycyrrhizin, also known as glycyrrhizic acid. This has hormonal effects resembling those of aldosterone, an adrenal gland hormone that is responsible for maintaining mineral balance in the blood. It helps the body retain sodium and excrete potassium. An excess of aldosterone, or compounds that behave like it, will cause excessive sodium retention which in turn causes excessive water retention which then causes high blood pressure.  Loss of potassium can affect nerve and muscle function.  In the case of our licorice-guzzling patient, potassium supplementation quickly reversed the problem.

This case is not unique. A man who switched to a licorice flavored beverage when he was told to give up alcohol also ended up in hospital with weakness, high blood pressure and low potassium. So did a man who had managed to give up smoking by switching to chewing gum flavored with real licorice. His severe abdominal pains turned out to be due to potassium loss. A man who chewed about ten 3-ounce bags of tobacco a day became so weak he couldn’t raise his arms.  Licorice is commonly used to flavor tobacco. In fact, about 90% of the licorice imported into North America is used for this purpose. When volunteers were asked to eat licorice candies to the tune of one to two hundred grams daily, serious symptoms appeared within a few weeks. So the moral here is obvious. Do not consume unusual amounts of authentic licorice, especially if there is a history of high blood pressure or other medical problems like diabetes, heart disease or glaucoma.

Why should anyone consider eating exceptional amounts of licorice anyway? There seem to be plenty of reasons when one consults the herbal or alternative literature. Often licorice is touted as a “natural” treatment for conditions ranging from colds and prostate problems to indigestion and cancer. In most cases the results of animal experiments are blown out of proportion and human experiences are exaggerated. For example, just because mice exposed to a carcinogen developed fewer tumors when they drank water laced with glycyrrhizin does not mean that licorice is an effective treatment for human cancer. Just because there is some evidence that licorice can help heal peptic ulcers in humans does not mean it is the best therapy. It may have been an appropriate treatment until newer, far more effective prescription drugs came on the scene.

There is one area, however, that does merit a closer look. And that, believe it or not, is the use of licorice in the treatment of chronic fatigue syndrome (CFS). This is a baffling and potentially devastating condition. It is not just run of the mill fatigue. It comes along with headaches, muscle pains, “mental fog” and depression. In 1995, Dr. Riccardo Baschetti, a retired Italian physician, submitted a letter to the New Zealand Journal of Medicine, describing how he had cured himself of the condition using licorice root.  Because he had noted that he felt better after eating salty foods, Baschetti wondered if eating licorice, which he knew caused sodium retention, might be an antidote for CFS. He described how he dissolved about five grams of licorice powder in milk and drank the concoction.  Within two hours he felt virtually cured!

Other researchers picked up on this idea and began to explore the possibility that CFS may in some cases be due to low blood pressure and may be treatable with licorice. They saw results, but only in patients who had enlarged lymph nodes which can be associated with chronic fatigue syndrome. If it does turn out that CFS is somehow associated with adrenal insufficiency, in other words, low levels of aldosterone, then treatments based on hormonal supplementation can be devised. These will be more reliable than experimenting with licorice. For now, it goes without saying that anyone who wants to try licorice should do so only under a physician’s care because blood pressure and potassium levels must be monitored.

Because of current interest in licorice, researchers at the University of Padua in Italy asked young men to eat seven grams of licorice tablets (0.5 grams of glycyrrhizic acid) a day for a week to study potential effects. Their testosterone levels dropped by 44% in just four days. Ouch! It seems that men who eat lots of licorice may not be able to indulge their sweethearts! But single large doses may not have this effect. Not if we judge by Chaplin’s shoe-eating episode. Charlie married four times in his life, each time taking a bride under twenty years of age.  No lack of testosterone there.

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