Why Your Stomach Will Love Turmeric and Licorice

Add Spice and Sweetness to Your Life

Why Your Stomach Will Love Turmeric and Licorice
These ancient medicinal remedies have been
shown to kill H. pylori, the cause of most ulcers
By Hyla Cass, M.D.

hen the archeologist Howard Carter opened the tomb of King Tutankhamen in 1922, some 33 centuries after it had been sealed, treasures of unimaginable splendor were revealed to an incredulous world. The chambers were filled with golden objects. Surrounding the massive quartzite sarcophagus, which contained the mummy and its magnificent, solid gold death mask, were innumerable artifacts left by the boy king’s faithful subjects to buoy him on his journey to the netherworld.

The variety of relics found in the tomb was staggering. There were statues, chariots, miniature ships, furniture, toys, perfumes, jewelry, and much more. Also found, however, were “treasures” of a more mundane nature: spices and other foodstuffs to sustain the king’s spirit in the afterlife. Among them was an especially thoughtful item, designed to enable him to brew a sweet, delicious drink for refreshment: a bundle of licorice root.

Licorice—A Medicine for the Ancients . . .

Licorice, a treasure fit for a king? Yes indeed. Licorice was highly prized by the ancients for its sweetness, and placing it in the tombs of the dear departed for their later enjoyment was a common practice. It’s even possible that some of those lucky stiffs went to their maker later than they would have if licorice had not been around while they were alive.

It was not just the sweetness that made licorice so popular with the living, but also its medicinal qualities. Like many other herbal products, licorice became enshrined in folk medicine thousands of years ago. It was deemed particularly helpful for treating ulcers, gastritis (inflammation of the stomach), and various other gastrointestinal ailments.

Licorice was also used as a general anti-inflammatory agent and in the treatment of bowel irritations, bronchitis, cough, sore throat, and canker sores. People in southern Europe used to drink licorice water, believing it to be a blood purifier. And the Romans thought so highly of licorice that they included it in the rations for the Roman legions. (For more fun facts about licorice, see the sidebar on this topic.)

All About Licorice

We all know licorice as that black, rubbery candy that some people love and some people hate—there doesn’t seem to be much middle ground. The flavor certainly is distinctive. Probably not one person in a hundred, however, knows where licorice comes from, so get ready to find out. If you memorize the remainder of this sidebar, you can recite it the next time you get together with your friends—you’ll be the life of the party.

The word licorice comes, via Middle English and Old French, from the Late Latin liquiritia, an alteration of the Latin glycyrrhiza, which comes from the Greek glukurrhiza (from glukus, sweet, and rhiza, root).

Licorice (sometimes spelled liquorice) comes from an extract of the long, thick, sweet-tasting root of the licorice plant, Glycyrrhiza glabra. This tall, perennial, leguminous herb (a member of the pea family) has blue flowers. It is native to the Mediterranean region and is widely cultivated in southern Europe and in western and central Asia. The roots are dried for several months and then packaged for shipment to processing plants, where the extracts are prepared, generally in the form of a gummy or rubbery paste that has a sweet, rather astringent flavor. The leftover root fibers are used in the manufacture of fire-fighting foam, insulation board, and other products.

The flavor of licorice comes mainly from a compound called anethole, which is also found in anise, fennel, and other herbs. The sweetness, however, comes from glycyrrhizic acid, which is about 50 times as sweet as sugar—a little goes a long way. There’s a lot more to licorice than candy and chewing gum, though. Licorice is also used as a flavoring agent for liqueurs, soft drinks, and chewing tobacco. And it’s used in the manufacture of shoe polish (so if some arrogant lout should demand that you lick his boots, you could try it—it might taste good!).

. . . And for Us Moderns

We now know that licorice has antioxidant, anti-inflammatory, antibacterial, antiulcer, antifungal, and antithrombotic properties, and it may have anticancer properties as well.1 In modern medicine, licorice extract is used primarily as a mild laxative, a demulcent (an agent that soothes and relieves irritation, especially of mucous membranes), and an expectorant (an agent that promotes the secretion or expulsion of phlegm, mucus, etc., from the respiratory tract).

Licorice is especially popular in cough medicines, not just for its demulcent and expectorant properties but also for its other major use in the medicinal arena: to mask the unpleasant (sometimes quite disgusting) flavors of other agents. In Germany, licorice extract is used for the treatment of gastric and duodenal ulcers and for catarrhs of the upper respiratory tract. And in Japan, one of its components is used in the treatment of chronic hepatitis and cirrhosis of the liver, owing to its protective effect on liver cells.

The Same Goes for Turmeric

Another herb with a distinguished history of use since ancient times is turmeric, the spice that gives many curries and mustards their characteristic yellow color. Turmeric (Curcuma longa), a member of the ginger family, is a tall perennial plant with yellow flowers. When dried and ground up, its fleshy, aromatic rhizomes (rootstalks) yield the bright yellow powder that people have prized for millennia for its pungent flavor. Turmeric’s most prevalent use has been in its native India, where it’s a common remedy in the traditional medical practice called Ayurveda.

In primitive cultures lacking refrigeration, turmeric has long been used to retard the spoilage of meat and help preserve its nutritive value—undoubtedly the result of strong antioxidant action. The spice can also, however, preserve and protect living “meat,” such as ourselves, owing to its wide range of beneficial actions in the human body. In addition to its antioxidant action and its strong anti-inflammatory action (the latter makes it a widely used treatment for arthritis), the following medicinal properties have been attributed to turmeric: antimicrobial, antitumoral, anticholesterol, antithrombotic, and antihepatotoxic (liver-protective).1 From this impressive résumé, it’s easy to understand why turmeric has traditionally been called “the spice of life.”*

*For more on the remarkable health benefits of turmeric, see “Turmeric May Help Prevent Alzheimer’s and Parkinson’s Diseases” (February 2002), “Turmeric Protects Your Brain Cells” (July 2004), and “Turmeric Is ‘The Spice of Life’” (November 2004). See also this sidebar on turmeric:

Turmeric Suppresses Stomach Acid

The stomach is a useful organ, but its not really essential. People can survive just fine with no stomach at all—and some people do, because their diseased or injured stomachs were surgically removed (they do have special nutritional requirements, though, so that their intestines can handle the task of digestion). Others have their stomachs surgically reduced in size in order to help them eat less and thus lose weight.

One thing that never happens, though, is to have the stomach ligated (tied shut) at the base, preventing anything from exiting to the duodenum. That, however, is a classic experimental technique used in rats to study the effects of drugs or nutrients on gastric hyperacidity, or excess acid secretion. When the pylorus (the sphincter at the base of the stomach) is ligated, hyperacidity develops quickly and causes ulceration of the stomach’s mucous lining.

In South Korea recently, scientists used this technique to study the effects of a turmeric extract compared with those of ranitidine, a drug that reduces the stomach’s secretion of hydrochloric acid. Ranitidine is commonly prescribed for gastric and duodenal ulcers and gastroesophageal reflux (heartburn).1

Rats that had been deprived of food, but not water, for 18–24 hours were given an aqueous extract of turmeric (Curcuma longa), aqueous ranitidine, or plain saline solution orally. One hour later, they were lightly anesthetized and their pylori were ligated via a small abdominal incision. Eight hours after that, they were killed, and their stomachs were carefully removed, opened up, and examined microscopically for evidence of ulceration.

As expected, saline solution did not protect the rats’ stomachs from the ligation-induced hyperacidity—there was extensive ulceration of the gastric mucosa. In both the turmeric-treated and ranitidine-treated rats, however, ulceration was markedly reduced: both of these agents strongly suppressed hyperacidity, apparently through their inhibitory effect on certain histamine receptors called H2R, which are involved in gastric acid secretion. Curcumin, the principal active component of turmeric, was inactive in this regard, but other turmeric components were obviously not.

The authors stated,

The selective inhibition by C. longa of H2R and gastric acid secretion indicate [sic] that C. longa extract or its active component(s) may be promising therapeutic candidates for the treatment of gastric ulcers and other H2R related diseases.


  1. Kim DC, Kim SH, Choi BH, Baek NI, Kim D, Kim MJ, Kim KT. Curcuma longa extract protects against gastric ulcers by blocking H2 histamine receptors. Biol Pharm Bull 2005;28(12):2220-4.

H. pylori Can Kill People

Now that we know all about licorice and turmeric, it’s time to see what has brought them together in this article. It turns out that both of them—but turmeric especially—are effective killers of one of the most destructive bacteria known to humankind: Helicobacter pylori.2 This malevolent bug infects the gastrointestinal tracts of about half the people on earth. It’s the primary cause of gastric and duodenal ulcers (collectively called peptic ulcers), as well as gastritis and stomach cancer.

The World Health Organization classifies H. pylori as a Class 1 carcinogen (“known human carcinogen”). Although most infected people remain asymptomatic, they are believed to have low-level gastritis, and about 5–10% of them eventually develop severe gastric or duodenal disease—mainly ulcers, but also cancer.

Turmeric and Licorice Kill H. pylori

An international team of researchers from England, Sri Lanka, Italy, and France recently conducted laboratory studies of the effects of 25 culinary and medicinal plants against H. pylori.2 By boiling the appropriate plant parts in water, they obtained simple aqueous extracts simulating the ones used in primitive cultures, which lack the more sophisticated chemical extraction techniques used in industrialized countries. They used these aqueous extracts against a standard reference strain of H. pylori and against six fresh clinical strains obtained from Italian patients with peptic ulcer disease. The idea was to measure the killing efficiency of the extracts and the time required for maximum action.

Turmeric emerged as the clear champion in these tests, killing 100% of the bacteria within 15 minutes. Licorice too killed 100%, although it took longer: up to 60 minutes. Curiously, the effects in all 25 plants were all-or-nothing within the 60-minute limit: 17 plants killed H. pylori with 100% efficiency or extremely close to it (high 90s), and 8 plants were duds, with 0% killing. The results of these experiments confirmed what had been published previously regarding the bactericidal effects of turmeric3 and licorice4,5 against H. pylori.

If You Don’t Kill Them, Flush Them

The researchers also measured the plant extracts’ ability to inhibit the adhesion of H. pylori to the inner lining of the stomach—a biochemical process that’s critical for the bacteria’s ability to take up residence there and cause long-term infection. This experiment represents an interesting and potentially useful therapeutic approach, complementary to the outright killing of the bacteria. If one could prevent them from taking up residence in the GI tract, it would not even be necessary to kill them—they would just be flushed out, so to speak.

Licorice (Glycyrrhiza glabra)
For these experiments, the researchers used histological sections prepared from biopsied samples taken from the stomachs of healthy humans with no H. pylori infection. They labeled bacterial colonies of H. pylori with a fluorescent dye to make them easily visible under a microscope, incubated the labeled bacteria with samples of the plant extracts, and applied these brews to the stomach sections. As a reference sample, they used H. pylori in distilled water, which appeared to have no antiadhesive effect. Only three plants were effective here: turmeric, borage, and parsley. Turmeric was again the winner, with an antiadhesive efficiency of 62%.

Although it’s a long way from a laboratory bench to a living, churning human stomach, full of … whatever, these results are encouraging. They should provide the impetus to pursue such studies through clinical trials—the ultimate test of therapeutic efficacy.

The Potential Problem with Licorice . . .

The medicinal properties of turmeric are attributed mainly to a polyphenolic compound called curcumin, along with a group of related compounds called curcuminoids. As a group, they represent a formidable threat to microbes of many kinds.

We also know what many of the active agents in licorice are. The extract contains dozens of biologically active compounds (mostly flavonoids and saponins), the most prevalent of which is glycyrrhizic acid (that’s pronounced gliss·sir·RYE·zik).* In the GI tract, this compound is almost completely converted to its principal metabolite, glycyrrhetinic acid (gliss·sir·reh·TIN·ic). Thus, virtually no glycyrrhizic acid gets into the bloodstream—but glycyrrhetinic acid does.

*An alternate name for this compound is glycyrrhizinic acid, and it’s sometimes loosely called glycyrrhizin; the latter, however, actually denotes salts of glycyrrhizic acid.

Both compounds kill H. pylori and hence have antiulcer activity (as do many of the other compounds in licorice extract). Unfortunately, however, they also pose a potential health risk if licorice—whether as candy or medicine—is consumed in excessive amounts. Glycyrrhetinic acid (the one that enters the bloodstream) can induce sodium and water retention and loss of potassium, resulting in edema and increased blood pressure—not good.

. . . Is Easily Solved through Deglycyrrhizination

To protect the licorice-happy public from getting too much of these compounds in their favorite treats, most licorice-containing consumer products are deglycyrrhizinated (de·gliss·sir·RYE·zin·a·ted), meaning that the glycyrrhizic acid and any glycyrrhetinic acid have been removed, so the products are safe for overindulgence (check the label to be sure). Actually, most “licorice” candies and gums contain little or no licorice extract to begin with—they’re flavored with anise, which is perfectly safe.

Licorice products for long-term medicinal use need not be deglycyrrhizinated if the amount of glycyrrhizic acid they contain does not exceed 100 mg/day, which is considered to be acceptable and safe.5 To achieve this relatively low level, however, requires an amount of licorice extract smaller than those usually desired in antiulcer medications, and this means that the dozens of other active ingredients in licorice would also be present in suboptimal amounts.

To get around this problem, many medicinal licorice products contain deglycyrrhizinated licorice (DGL). In sacrificing the medicinally valuable but potentially harmful glycyrrhizic and glycyrrhetinic acids, the tradeoff is that the other medicinally valuable active ingredients, which also have antiulcer activity, can be present in the desired amounts, with no potential for harm.

You Can Stomach This

You may not be a king or queen, but you’re alive and, I hope, well. A good way to stay that way is to protect your gastrointestinal tract from the harm that H. pylori can cause. For thousands of years, people have been good to their stomachs (whether they knew it or not) by eating such healthful and tasty foods as turmeric and licorice—and, of course, mastic, the gum resin obtained from the mastic tree (Pistacia lentiscus) on the Greek island of Chios. By killing H. pylori, these foods have probably brought immeasurable relief to countless people through the ages, and they may have prolonged their lives as well. So take a lesson from the ancients, and take good care of your stomach.


  1. PDR for Herbal Medicines, 3rd ed. Thomson PDR, Montvale, NJ, 2004.
  2. O’Mahony R, Al-Khtheeri H, Weerasekera D, Fernando N, Vaira D, Holton J, Basset C. Bactericidal and anti-adhesive properties of culinary and medicinal plants against Helicobacter pylori. World J Gastroenterol 2005;11(47):7499-507.
  3. Mahady GB, Pendland SL, Yun G, Lu ZZ. Turmeric (Curcuma longa) and curcumin inhibit the growth of Helicobacter pylori, a group 1 carcinogen. Anticancer Res 2002;22:4179-81.
  4. Fukai T, Marumo A, Kaitou K, Kanda T, Terada S, Nomura T. Anti-Helicobacter pylori flavonoids from licorice extract. Life Sci 2002;71:1449-63.
  5. Krausse R, Bielenberg J, Blaschek W, Ullmann U. In vitro anti-Helicobacter pylori activity of Extractum liquiritiae, glycyrrhizin, and its metabolites. J Antimicrob Chemother 2004;54:243-6.

Dr. Hyla Cass is a nationally recognized expert in integrative medicine, an assistant clinical professor of psychiatry at the UCLA School of Medicine, and the author or coauthor of several popular books, including Natural Highs: Supplements, Nutrition, and Mind-Body Techniques to Help You Feel Good All the Time and 8 Weeks to Vibrant Health: A Woman’s Take-Charge Program to Correct Imbalances, Reclaim Energy, and Restore Well-Being.

Featured Product

  • Learn more about St benefits and implementation strategies.

FREE Subscription

  • You're just getting started! We have published thousands of scientific health articles. Stay updated and maintain your health.

    It's free to your e-mail inbox and you can unsubscribe at any time.
    Loading Indicator