Licorice: The Good And The Bad
Almost everyone knows about licorice as a food and candy. What many people do not know, however, is that licorice is also a potent and valuable herbal medicine, widely used as a therapeutic agent.
According to Natural Medicines database, licorice (Glycyrrhiza glabra) can be used for the following conditions: “Orally, licorice is used for gastric and duodenal ulcers, sore throat, bronchitis, chronic gastritis, dyspepsia, colic, menopausal symptoms, Addison’s disease, cough, osteoarthritis, osteoporosis, systemic lupus erythematosus (SLE), and for bacterial and viral infections. It is also used orally for cholestatic liver disorders, nonalcoholic fatty liver disease, hyperkalemia, hypertonia, malaria, tuberculosis, abscesses, food poisoning, diabetes insipidus, chronic fatigue syndrome (CFS), postoperative recovery, contact dermatitis, and hypercholesterolemia.” And, in Traditional Chinese Medicine, licorice is included in nearly all herbal formulas for the purpose of “harmonizing” the various herbs incorporated in the mixture.
That’s the good news. The bad news is that any substance, herbal or otherwise, that exerts a therapeutic (or pharmacologic) action, will also exhibit the potential for adverse effects as well.
If you suffer from low blood pressure, a natural substance that increases blood pressure can be considered beneficial, but if you suffer from high blood pressure, that same natural substance’s hypertensive action can be considered an “adverse effect.”
Whole licorice, whether from food or in supplements, can theoretically raise blood pressure. It contains a substance called glycyrrhizin which, when taken in large enough quantities, exerts an action in the body similar to the hormone aldosterone. This hormone causes fluid retention, loss of potassium, and increased blood pressure.
How concerned should you be about this?
The answer, for most people, is less concerned than you might initially think. For one thing, much of the food or candy we buy it not really licorice at all–it contains anise oil, which imparts the characteristic smell and taste we call “black licorice.”
In addition, much of the licorice used in supplements has had the glycyrrhizin removed. This results in a product called “DGL,” which stands for deglycyrrhizinated licorice. Supplements containing DGL, for example, are widely used for treating gastric and duodenal ulcers.
Does that mean there are no products that contain “whole” licorice? No, not at all. Whole licorice is still used in various products. It may still be found, for example, in liquid cough and asthma remedies, functioning as an expectorant. As mentioned above, it is widely used in Chinese herbal remedies. And, licorice root is in the PhytoTech supplement, Mushroom Extract Complex.
The question, then, is how much whole licorice is too much?
Dosages of whole licorice in the range of 5 to 15 grams per day is generally thought to be acceptable for no more than a few weeks. For long-term use, about 0.3 grams (300 mg) of licorice root daily should be safe for most adults.
“Current evidence indicates that individuals who wish to take whole licorice on a long-term basis without any risk of these side effects should not consume more than 0.2 mg of glycyrrhizin per kilogram of body weight daily. For a person who weighs 130 pounds, this works out to 12 mg of glycyrrhizin daily. Based on a typical 4% glycyrrhizin content, this is the equivalent of 0.3 grams of licorice root.” (reference: ConsumerLab.com) For a person weighing 184 lbs, the safe amount of whole licorice, or licorice root, would be 427 mg.
It is understood that “small amounts” of licorice is not a problem for those with high blood pressure. The question, of course, is what does “small amount” mean. Based on the above calculation, we can say that for an adult, levels below 300 to 427 mg per day should not be a problem.
Another reference source, Natural Medicine, presents the following information: “. . . long-term use (months to years) or intake of large amounts (up to 20-30 grams) can increase the risk of adverse effects such as hypertension and hypokalemia. In people with hypertension, cardiovascular or kidney conditions, or a high salt intake, intake of as little as 5 grams [per] day can cause these problems.” They also point out that “. . . when used orally in amounts commonly found in foods. Licorice has Generally Recognized as Safe (GRAS) status in the US “ (Note: 5 grams is equal to 5,000 mg.)
How much is in PhytoTech Mushroom Extract Complex? The label states the content is 44 mg per serving of licorice root, and the recommended dose is 2-3 servings per day–well within the safe range.
It is noteworthy, by the way, to point out that the PhytoTech Mushroom Extract Complex label provides the actual quantitative information of all five herbal ingredients. Not all products provide this information, often presenting only qualitative listings, under the heading “proprietary blend.”
In summary, for those concerned about licorice and hypertension, small amount of whole licorice, or licorice root, even when used long term, should not be a problem. Small amounts can be defined as less than 500 mg per day. The amount in products such as PhytoTech Mushroom Extract Complex (44 mg, 2-3 times a day), is only one-tenth that level.
(1) comments from Dr. Alan Gaby, published in his book: Gaby, Alan R., M.D.. Nutritional Medicine (Second Edition). Alan R. Gaby, M.D., 04/2017
“. . . Compounds present in Glycyrrhiza glabra (licorice root) potentiate the effects of glucocorticoids and mineralocorticoids by slowing the rate of their catabolism.4–8 Thus, in non-adrenalectomized patients, glucocorticoid and mineralocorticoid activity can be increased by administering licorice root extracts. Prior to the introduction of synthetic steroids, licorice root was one of the standard treatments for Addison’s disease.9 Licorice root is also a viable alternative to cortisol in patients with mild hypoadrenalism.
I have seen about 15 patients with a clinical picture suggestive of mild hypoadrenalism in whom treatment with a licorice tincture led to improvements in symptoms such as fatigue, hypotension, and poor stress tolerance. The usual dosage was 2–6 drops twice a day of a 1:1 or 1:2 tincture, or 6–10 drops 2–3 times per day of a 1:3 tincture.
Potential adverse effects of licorice root include hypokalemia and hypertension. These side effects are extremely unlikely with the low doses I have used. Nevertheless, I advise patients taking licorice root to consume abundant amounts of fruits and vegetables (or to supplement with 200–300 mg/day of potassium) and to monitor their blood pressure. Patients taking glucocorticoids or mineralocorticoids should, in most cases, not take licorice root. The dosages of licorice I have used are unlikely to interact with dehydroepiandrosterone (DHEA), although a much larger dose of licorice (100 g/day for 9 weeks) was found to decrease serum DHEA-sulfate levels in healthy men but not in women.”
(2) Selected references from Natural Medicines database:
Mechanism of Action
“General: The applicable part of licorice is the root. Although licorice contains saponins, flavonoids, isoflavonoids, flavones, and chalcones, the main active constituent is considered to be glycyrrhizin, otherwise known as glycyrrhizic acid or glycyrrhizinic acid (59755, 59773, 59806, 59854, 59891). Glycyrrhizic acid content of licorice preparations is typically around 2-3 mg/gram (0.2% to 0.3% w/w), but can vary from 0.026-98 mg/gram (15598, 15600). . . .
“Anti-cancer effects: Licorice is used in combination with other herbs to treat prostate cancer. In human research, a combination product including licorice was used to reduce prostate specific antigen (PSA) levels (6286). Licorice may also be useful for other types of cancer. In an animal model, licorice extract inhibited colon cancer growth (59763). A mechanism of action is not clear. However, the metabolite glycyrrhetinic acid has been shown to reduce cellular adhesion and induce cell death in tumor cells in laboratory research (59804). Also, the licorice flavonoid glabridin has been shown to inhibit cellular migration, invasion, and angiogenesis in laboratory research (59813). . . .
“Immunomodulatory effects: In human research, consumption of a licorice herbal tincture stimulated immune cells, as quantified by CD69 expression on CD4 and CD8 T cells (32825). In animal research, an herbal product containing licorice increased the number of leukocytes in the spleen and liver and increased splenic natural killer toxicity. However, in this study, the product did not affect the production of inflammatory cytokines or other agents (59710). Furthermore, in laboratory research, the aglycone derivative of glycyrrhizin, beta-glycyrrhetinic acid, inhibited human complement activity (59904). . . .”
Natural Medicines, Somerville, MA 02144 USA