The root of the licorice plant, Glycyrrhiza glabra, is well-known globally as a strong flavoring agent used in confectionery and beverages. It has also held a prominent place in traditional medicine systems across Asia and Europe for thousands of years, primarily consumed orally as a tea, extract, or chewable stick. Given the increasing interest in herbal smoking alternatives, an inquiry arises regarding the safety and feasibility of smoking licorice root. While physically possible to dry and burn the root, this practice introduces a different set of chemical exposures and systemic health risks compared to its traditional use.
The Practice of Smoking Licorice Root
Licorice root is currently utilized in various commercial and homemade herbal smoking mixtures, not typically as the sole ingredient. It is sometimes included in these blends to impart a subtly sweet flavor to the smoke, appealing to those seeking an alternative to tobacco. The root also contains certain compounds that can reduce the perceived harshness of the smoke, allowing it to function as a smoothing agent when combined with other herbs.
The physical nature of the dried root allows it to be shredded and incorporated into smoking materials, where it combusts easily. Although some proponents claim the practice offers soothing effects, the root’s inclusion is primarily textural and for flavor modification. However, the act of burning any plant material, including Glycyrrhiza glabra, fundamentally changes its chemical structure, which dictates the safety profile.
Chemical Transformation During Combustion
The defining characteristic of licorice root is the triterpenoid saponin known as glycyrrhizin, which is fifty times sweeter than sugar. When the root is subjected to the high temperatures of combustion, pyrolysis occurs, breaking down the complex organic molecules into simpler, often toxic, compounds. This thermal degradation of glycyrrhizin begins at temperatures easily reached when smoking, leading to the formation of its aglycone, glycyrrhetinic acid, and other byproducts.
Combustion also generates substances that are not present in the unburnt root. These include a range of known irritants and carcinogens such as formaldehyde and polycyclic aromatic hydrocarbons (PAHs). Formaldehyde concentrations increase in the smoke of cigarettes containing licorice extract, and the burning of licorice root has been specifically cited to produce benzene, a potent carcinogen.
Respiratory and Systemic Health Implications
Inhaling the smoke from licorice root introduces particulate matter and newly formed toxic compounds directly into the respiratory tract. General smoke inhalation, regardless of the source material, carries a baseline risk of lung damage and irritation due to the fine particles and harsh gases produced. The presence of chemicals like benzene and formaldehyde significantly elevates the danger, exposing the airways and lungs to known respiratory irritants and cancer-causing agents.
Beyond the general risks of smoke, the unique compounds in licorice root pose a specific systemic threat when inhaled. The active component, glycyrrhizin, or its breakdown product glycyrrhetinic acid, is readily absorbed through the lung tissue into the bloodstream, bypassing the initial metabolic processes of the digestive system. This can lead to pseudoaldosteronism, a condition that mimics the effects of excess aldosterone in the body.
The primary systemic consequences of this effect are hypertension and hypokalemia, an abnormally low level of potassium in the blood. Hypokalemia can cause muscle weakness, lethargy, and, in severe cases, dangerous cardiac arrhythmias. Studies involving occupational exposure to licorice root dust found an association with these exact symptoms, including elevated blood pressure and reduced potassium levels.
Standard Applications of Licorice Root
The use of licorice root involves ingestion, which allows the body to process its components through the digestive tract. The root is widely used as a natural sweetener in candies, lozenges, and teas due to the high sweetening power of glycyrrhizin. It has also been employed in traditional remedies for managing digestive issues, such as stomach ulcers, and for soothing respiratory complaints like coughs and sore throats.
In a therapeutic context, licorice is often consumed as a standardized extract or as a deglycyrrhizinated licorice (DGL) product, where the glycyrrhizin is removed to mitigate the risk of adverse cardiovascular effects. Chewing on a simple licorice stick has also been historically used as a natural alternative to help individuals cope with the oral fixation associated with smoking cessation. These applications focus on controlled oral consumption, which is the established and well-researched method for utilizing the herb’s properties.