Licorice refers to the roots and rhizome of a variety of plants belonging to the species Glycyrrhiza glabra L. of the family Fabaceae. This is a European species and possesses a sweet yellow wood. There are also Asian species of the plant like Glycyrrhiza uralensis Fisch. and others. In the commercially available licorice in the US markets all these species are included since a significant part of licorice is imported from China and other Asian countries.
However, licorice roots and licorice candy, especially those available in the US, has nothing or very little to do with each other. These two are entirely different products but unfortunately there is a strong misconception regarding the two products among people. Licorice candy gets its flavor from anise oil and contains very little or no licorice whatsoever. Anise oil has a flavor that is strikingly similar to that of licorice and because of this it is often confused with licorice, but the resemblance ends there. The properties are very different and where licorice roots are potentially toxic the other is quite common and harmless.
Nonetheless, recently a case of licorice overdose was reported in the US and on further investigation it was found that the culprit was the popular candy Twizzlers. It appears that the black variety of the candy contains some licorice. Licorice is also found in candies imported from Europe, where they don't use anise or other flavoring agents.
Authentic licorice candy is very popular in Britain and in most parts of Europe, but not so much in America. Most of the licorice that reaches the United States is used to flavor tobacco products like cigarettes, pipe tobaccos, cigars and so on. It is estimated that 90 percent of the millions of pounds of licorice that is imported to the United States annually is used for this purpose. The perceptible sweetness and pleasant flavor that many commercial tobacco blends have is due to the presence of licorice. The amounts of licorice used to get the required flavor and sweetness is a trade secret and is never revealed by the tobacco companies. Another use for licorice is as an ingredient in throat lozenges and various other pharmaceutical products.
Licorice gets its sweetness from glycyrrhizin, which is a saponin glycoside present in the roots. On an average 5 to 9 percent of the roots are made up of glycyrrhizin, which is fifty times sweeter than sugar. It is otherwise known as glycyrrhizic acid and is commercially available in a form known as ammoniated glycyrrhizin. The structure and physiological effects of glycyrrhizin are related to aldosterone or desoxycoticosterone. This is possibly why a condition which medical literature terms as pseudoaldostronosm is brought about in licorice by glycyrrhizin. This condition is similar to the one brought about by excessive secretion of aldosterone which is an adrenal cortex hormone. Excessive quantities of this in the human body can be disastrous. It can lead to high blood pressure and in some cases even heart failure and cardiac arrest. Other symptoms like headache, lethargy, sodium and water retention and excessive excretion of potassium are also seen.
High rate of consumption of licorice especially by people suffering from high blood pressure or heart trouble could have serious consequences. With increased consumption, its toxic effects are apparent within a matter of days or a single week. There is for instance one popular herbal cough remedy available in the market which if over used could be really bad. It contains 1 ounce of licorice root per quart of water and the directions suggest one half pint at bedtime. Also suggested are additional quantities as and when needed. This means that the daily amount might be doubled or even tripled depending on the person and the frequency of use. With each half pint easily containing 0.5 gram of glycyrrhizin, the amount of glycyrrhizin in the body could easily reach toxic proportions.
Off late, deglycyrrhizinated licorice products have started to make their appearance in the American market as the toxicity associated with glycyrrhizin is quite well documented. These deglycyrrhizinated licorice products may have some residual activity, but with the principal constituent being removed, it will surely be less harmful. While its flavor might please a lot of people and it might be useful to a certain extend in the treatment of coughs, colds and certain other ailments, its potency and toxicity will always be a matter of concern. Its use in large doses and for an extended period of time is certainly not advisable.
Its affinity for the endocrine system makes licorice a most remarkable herb, which when used judiciously can be very helpful in treating many human ailments. Licorice has an anti-inflammatory, antiallergic and antiarthritic effect similar to that of cortisone but without its side effects. This is because of glycyrrhizin which has a structure similar to hormones produced by the adrenal glands. Its antiallergic effect makes it very useful in treating allergic rhinitis, hay fever, conjunctivitis and bronchial asthma. Licorice has mild estrogenic properties and can be very helpful during menopause. It gets these properties from the steroid like compounds present in it which can change to estrogen precursors like estradiol and estrone. Licorice can act as a mild laxative and can also relieve indigestion and heartburn by lowering stomach acid levels.
Documentary and other scientific evidence suggest that licorice was known and was put to a variety of uses for many centuries, generally as medicine and as a flavoring agent of food and other medicinal herbs. From ancient literature, primarily those of Hippocrates and Pliny the elder, the herb's use as medicine is evident. The use of the dried roots and rhizomes of the plant as a digestive aid and for coughs and colds is clearly described. Further more, a piece of licorice dating back to the eighth century was recently discovered- it still contained active principles of the herb.
One can find licorice mentioned in ancient Chinese texts as well. A wonderful summarization of the uses of licorice found in an ancient Chinese text says that it will “improve the tone of the 'middle Jiao' [digestive system] and replenish qi, to remove 'heat' and toxic substance, to moisturize the lungs and arrest coughing, and to relieve spasms and pain.” Modern day uses for licorice remain more or less the same, although the terminology used might be different. Chinese researchers also agree with their ancient counterparts and vouch for the herbs effectiveness against cough and in treating sore throat. In Europe, medical practitioners use the herb to treat coughs, colds and other respiratory infections. They say glycyrrhizinic acid present in licorice stops the growth of many bacteria and of viruses like influenza A. It is also thought to stimulate the production of interferon.
Licorice is said to be extremely useful in the treatment of stomach ulcers. Stomach ulcers heal quickly when there are high levels of prostaglandins in the stomach and the upper intestine. Licorice helps in bringing about higher levels of prostaglandins in the stomach and the upper intestine. This happens because licorice prevents the secretion of gastric acid and reduces the activity of pepsin. This in turn curbs the enzymes that dismantle prostaglandins. Studies done on rats also seem to corroborate this.
Physicians in Japan use licorice to treat hepatitis B as glycyrrhizin interferes with the hepatitis B surface antigen. Licorice is synergistic with interferon against hepatitis A virus and it is also used at times to treat the hepatitis C virus. The liver can be protected from the harmful effects of chemotherapy with licorice, say researchers. Licorice at low doses can help lower serum cholesterol levels by stimulating the liver to manufacture cholesterol and excrete it in bile. Licorice has the ability to prolong and increase the action of the steroid hormone cortisol produced by the adrenal glands. It does this by slowing down the conversion of cortisol into cortisone. Licorice can thus act more or less like a steroid.
China has found another use for licorice; licorice is used to treat pesticide poisoning. They consider licorice a powerful antitoxin. It is thought that licorice can also curb the malaria causing parasite, Plasmodium falciparum. The herb induces anti-inflammatory activity by its effects on adrenal steroids. Another important use for licorice is in helping to prolong the survival time of transplanted tissues. LX immunosuppressant, which does this by reducing hypersensitivity reactions, is a constituent of licorice. The antioxidant and antitumor properties of glycyrrhizin is well known, but regular use is not encouraged because of serious side effects. Researchers thought that licorice attached to estrogen receptors would promote the growth of uterine cells much like estrogen does. But in a study conducted, it failed to do so. In a more topical use, glycyrrhizin is made a constituent of certain shampoo brands to treat excess oil secretion of the scalp. It is also a part of certain ointments to treat skin diseases.
Licorice was mainly used for medicinal purposes. Ancient records from Greece and other places show it was used in treatment of asthma, chest problems, and canker sores.
Other medical uses
Habitat and cultivation
Originally it grew in the wild in many parts of Southeastern Europe and Southwestern Asia. But now licorice is extensively cultivated and can be found in many other parts of the world.
Research shows that licorice acts on the adrenal glands and stimulates the production of hormones and slows the breakdown of steroids by the internal organs. Studies have also found the anti-inflammatory and antiarthritic properties of glycyrrhizin that is quite similar to those of hydrocortisone and other corticosteroid hormones.
As said earlier licorice has its good and its bad points. The best thing to do is use it judiciously and with discretion. Glycyrrhizin can be very good for certain ailments while it is to be avoided for certain others. To circumvent this problem, licorice preparations with and without glycyrrhizin are available. Deglycyrrhizinated licorice or DGL is available and is best for treatment of the digestive tract in cases like ulcers. It comes in the form of 200-300 mg tablets and for best results it is to be chewed three times a day before meals and before bed. For mouth ulcers, DGL powder is mixed with water and swished in the mouth for three minutes and then spat out. The dosage is 200 mg of DGL mixed with 200 ml of warm water. Another dosage is a tincture of 2-5 ml of licorice taken three times a day.
Side effects and cautions
Long term and high intake of licorice which contains glycyrrhizin can be quite harmful. It can increase blood pressure and can cause retention of water in the body. Some people are more sensitive to glycyrrhizin and in them the effects are more pronounced. One gram of glycyrrhizin or about 10 grams of licorice root a day is enough to cause problems. So long term use should be avoided or should be done only under strict supervision of competent doctors. Another way to get around the problem is to use deglycyrrhizinated licorice extracts, which do not have any side effects.
How it works in the body
Licorice's effect on respiratory problems is mainly due to the presence of glycyrrhizin in it which acts as an expectorant and helps prevent and ease coughing. Glycyrrhizin, which is 50 times sweeter than sugar, and its derivatives act as anti-inflammatory and antiallergenic agents and this is the reason for its effectiveness. Its antiallergenic properties help in treating asthma. Licorice has a positive effect on the liver and helps the body rid itself of unwanted elements. It acts as a detoxifying agent. The Chinese have found a use for the herb in treating hepatitis and jaundice. Licorice gives the stomach walls a protective sheath of mucus thereby speeding up cure of stomach ulcers. Vomiting, nausea and bloating can also be treated using the herb.