Photo: AI-generated image created by Prof. Blundell
Liquorice, a plant with a storied history that spans centuries, has long been cherished for its distinctive sweet flavour and medicinal properties. From ancient Egypt, where it was included in tea blends for Pharaohs, to traditional Chinese medicine, where it's used as a remedy for various ailments, liquorice has been more than just a candy flavouring. However, like many substances that blur the line between food and medicine, liquorice comes with both potential benefits and risks. This article explores both sides, helping you make an informed decision about incorporating liquorice into your diet.
What is liquorice?
Liquorice, derived from the root of the Glycyrrhiza glabra plant, contains a compound called glycyrrhizin, which is primarily responsible for its sweet taste. Glycyrrhizin is far sweeter than sugar and has been used for centuries not just as a sweetener, but also as a herbal medicine.
The plant itself is native to Europe and Asia, where its roots are harvested and processed for use in a variety of products including sweets, teas and herbal remedies. In modern times, liquorice extract is often found in candies, beverages, and even some tobacco products, although many liquorice-flavoured products in the US use anise oil as a flavour substitute due to its similar taste.
Health benefits of liquorice
Liquorice has been a staple in herbal medicine for thousands of years, with many cultures using it to treat various conditions. Scientific research has begun to catch up, confirming some of these traditional uses.
Anti-inflammatory and immune-boosting properties: One of the most well-documented benefits of liquorice is its anti-inflammatory effects. Glycyrrhizin and its metabolites can modulate the immune system, making liquorice a potential treatment for conditions like asthma, allergies and autoimmune diseases. Its anti-inflammatory properties are also why it has been traditionally used to treat conditions like eczema and other skin disorders.
In addition to reducing inflammation, liquorice may also boost the immune system. Some studies suggest that liquorice root extract can enhance the body's production of interferon, a crucial protein that fights off viruses. This makes liquorice a potential ally in the fight against viral infections, including the common cold.
Digestive health: Liquorice has been used for centuries to treat various digestive issues, including ulcers, heartburn and gastritis. This is largely due to its ability to soothe the mucous membranes of the digestive tract. The compound glycyrrhizin in liquorice can help to reduce the symptoms of indigestion and promote healing of the stomach lining, making it a common ingredient in herbal remedies for acid reflux and peptic ulcers.
Liquorice may also help with constipation due to its mild laxative properties. This, combined with its ability to soothe the digestive system, makes it useful for maintaining overall digestive health.
Respiratory health: Liquorice has been traditionally used to treat respiratory conditions, including sore throats, bronchitis and asthma. The herb's soothing properties can help to reduce throat irritation and act as a natural cough suppressant. In some cultures, liquorice tea is a popular remedy for colds and other respiratory infections.
Stress relief and hormonal balance: Liquorice root is considered an adaptogen, a natural substance that helps the body adapt to stress and exert a normalising effect upon bodily processes. It may help regulate cortisol levels, the hormone most closely associated with stress. This can make liquorice beneficial for those suffering from chronic stress or adrenal fatigue.
Moreover, liquorice has a mild estrogenic effect, meaning it can mimic the action of oestrogen in the body. This has led to its use in treating symptoms of menopause, such as hot flashes and mood swings. However, this same property can be a double-edged sword, as it may exacerbate conditions related to hormonal imbalances.
Risks and side effects of liquorice
While liquorice offers several health benefits, it is not without its risks, especially when consumed in large quantities or over prolonged periods. The primary culprit behind these risks is glycyrrhizin, the same compound that gives liquorice many of its beneficial properties.
Hypertension (high blood pressure): One of the most significant risks associated with liquorice consumption is its potential to raise blood pressure. Glycyrrhizin can cause the body to retain sodium and lose potassium, leading to an imbalance in electrolytes. This can result in elevated blood pressure and, in severe cases, can lead to conditions such as hypokalaemia (low potassium levels), which can cause serious health issues, including arrhythmia (irregular heartbeat).
For this reason, individuals with high blood pressure or cardiovascular conditions should avoid liquorice or opt for deglycyrrhizinated liquorice (DGL), which has the glycyrrhizin removed but retains other beneficial compounds.
Hormonal effects: As mentioned earlier, liquorice can have oestrogen-like effects in the body. This can be beneficial for some individuals, such as those dealing with menopausal symptoms, but it can be harmful to others. For example, men who consume large amounts of liquorice may experience a decrease in testosterone levels, leading to reduced libido and other related issues. Women with hormone-sensitive conditions, such as breast cancer, should also be cautious about liquorice consumption.
Potential for drug interactions: Liquorice can interact with a variety of medications, potentially altering their effectiveness. For example, due to its potassium-lowering effects, liquorice can interfere with medications designed to lower blood pressure, such as diuretics. It can also affect the metabolism of corticosteroids and oral contraceptives, among other drugs.
If you are taking any medication, it is important to consult with a healthcare provider before consuming liquorice in significant amounts.
Toxicity and overconsumption: The risks associated with liquorice are particularly pronounced when it is consumed in large quantities or over an extended period. Regular consumption of liquorice candies, supplements, or teas containing glycyrrhizin can lead to chronic conditions such as oedema (swelling due to fluid retention), hypertension and hypokalaemia.
In rare cases, excessive consumption of liquorice has been linked to severe health events, including heart failure. This is why many countries have guidelines regarding the amount of glycyrrhizin that can be included in food products.
Pregnancy and liquorice consumption: Pregnant women should be particularly cautious with liquorice. Some studies have suggested that high consumption of glycyrrhizin during pregnancy could lead to developmental issues in the foetus, including reduced cognitive function and a higher risk of pre-term birth. Due to these potential risks, it is generally recommended that pregnant women avoid liquorice altogether.
A sweet treat with bitter consequences?
Liquorice is a fascinating plant with a long history of use in both culinary and medicinal contexts. Its health benefits, including anti-inflammatory effects, digestive support, and potential hormonal balancing, make it an appealing natural remedy. However, these benefits must be weighed against the potential risks, particularly for those with pre-existing health conditions or those who consume liquorice in large amounts.
Moderation is key when it comes to liquorice consumption. For most people, enjoying a liquorice-flavoured treat now and then is unlikely to cause harm. However, for those with high blood pressure, hormonal imbalances or who are pregnant, it may be best to avoid liquorice or opt for safer alternatives like DGL. Always consult with a healthcare provider if you have concerns about liquorice or if you're considering using it for medicinal purposes.
In the end, liquorice's dual nature - as both a sweet treat and a potent herbal medicine -reminds us that not all natural products are inherently safe, and even the most innocuous-seeming plant can have powerful effects on the body. Balancing the potential benefits against the risks is essential for making informed decisions about liquorice in your diet.
Renald Blundell is a biochemist and biotechnologist with a special interest in Natural and Alternative Medicine. He is a professor at the Faculty of Medicine and Surgery, University of Malta.