What is Liquorice?

Liquorice is an herb that grows in parts of Europe and Asia.

What are the potential health benefits of liquorice?

The root is used therapeutically. It is a herb that people have used for thousands of years for a variety of ailments. Stores of liquorice were found in the tombs of Egyptian pharaohs, including that of King Tut [i].

In herbal medicine liquorice is described as a demulcent, referring to its ability to relieve inflammation. It also has expectorant actions, relieving the lungs from excess mucus.

Liquorice root contains glycyrrhizin, it is thought that this component is responsible for most of its benefits. Liquorice root may have potent antioxidant, anti-inflammatory, and antimicrobial effects including anti-viral and anti-bacterial.

Eczema

Liquorice is often used in ointments to soothe eczema conditions, studies have shown liquorice extract gels to have significant anti-inflammatory effect on atopic dermatitis. Glycyrrhiza glabra extract, or liquorice root extract, may be effective against bacteria that can infect the skin, according to a study [ii]. The researchers used extracts from the leaves and roots of the plant. The study showed antimicrobial activity against Staphylococcus aureus, which can cause skin infections, such as impetigo, cellulitis, and folliculitis.

Digestive discomfort and stomach ulcers

A double-blind study found that an extract containing flavonoids present in liquorice root, was effective in relieving stomach and digestive discomfort. The extract also proved to reduce nausea and stomach pain [iii].

If infection in the stomach with a bacteria called Helicobacter pylori is present, peptic ulcers may occur in some people. A study of 120 patients found that the addition of liquorice extract to the standard medical treatment available, significantly improved H. Pylori eradication [iv].

Sore throat and upper respiratory tract conditions

Many people sort liquorice as a traditional remedy for sore throats. A study found that solutions with a high concentrations of liquorice were more effective than less concentrated solutions in improving sore throats caused by medical operations [v].

A study found the liquorice components liquiritin apioside and liquiritin are the major cough-reducing and expectorant (mucus loosening) compounds of liquorice [vi]. Liquorice also has a soothing effect on the respiratory tract and may prove to be beneficial in asthma alongside conventional treatment [vii].

Dental cavity protection

Test-tube studies also show liquorice root extract to be effective at protecting against bacteria commonly linked to cavities and tooth decay [ix].

Safety, precautions and potential side effects

Glycyrrhizin can cause adverse effects when eaten in large quantities, such as dangerously high blood pressure and dangerously low potassium levels (hypokalemia).

Lower potassium levels can lead to

Abnormal heart rhythms

High blood pressure

Swelling

Lethargy

Congestive heart failure

In general, an upper limit of 100mg/day glycyrrhizin is recommended, which approximates to 60 to 70g of liquorice sweets [x]. The active metabolites of glycyrrhizin, glycyrrhizic acid and glycyrrhetic acid, alter the adrenal stress response.

High amounts of liquorice should be avoided by lactating women. Liquorice consumption is also not recommended in pregnancy [xi].

Please consult with your prescribing doctor prior to taking liquorice supplementally, if you are on any medication. Medications that are known to interact with liquorice include:

Drugs that lower potassium

Blood pressure medications

Diuretics (to induce urination)

Heart rhythm medications

Blood thinners, such as warfarin (Coumadin)

Oestrogen, hormonal replacement therapy and oral contraceptive pills

Corticosteroids