The Core Culprit: Glycyrrhizin
The primary component in licorice root responsible for affecting blood pressure is glycyrrhizin, a compound that gives licorice its characteristic sweet taste. When ingested, glycyrrhizin is metabolized into glycyrrhetinic acid, which has a powerful effect on the body's hormonal system. The issue arises from how glycyrrhetinic acid interacts with an enzyme called 11-beta-hydroxysteroid dehydrogenase type 2 (11-β-HSD2) in the kidneys.
How Glycyrrhizin Inhibits a Key Enzyme
- Enzyme Inhibition: The 11-β-HSD2 enzyme is responsible for converting cortisol, a stress hormone, into its inactive metabolite, cortisone. This process is vital because cortisol has a very high affinity for mineralocorticoid receptors, similar to the hormone aldosterone, which regulates blood pressure.
- Cortisol Overload: When glycyrrhetinic acid inhibits 11-β-HSD2, cortisol is not properly inactivated and can then bind to the mineralocorticoid receptors at a much higher concentration than normal.
- Mimicking Hyperaldosteronism: This effectively creates a state known as pseudohyperaldosteronism, where the body's natural aldosterone production is suppressed, but the mineralocorticoid receptors are still over-activated by the excess cortisol.
The Cascade Effect on Blood Pressure
The activation of mineralocorticoid receptors by cortisol triggers a series of physiological responses that directly lead to an increase in blood pressure:
- Sodium Retention: The receptors' activation leads to increased reabsorption of sodium in the kidneys.
- Fluid Buildup: As the body retains more sodium, it also retains more water to maintain the proper salt balance, leading to fluid buildup and swelling (edema).
- Potassium Loss: In exchange for retaining sodium, the kidneys excrete more potassium, leading to low potassium levels (hypokalemia).
- Vascular Resistance: The imbalance in fluids and electrolytes, combined with an increase in arterial tone, increases the resistance to blood flow throughout the body.
- Higher Blood Pressure: The combination of increased fluid volume and vascular resistance forces the heart to work harder to pump blood, resulting in elevated blood pressure.
Risk Factors and How Much Is Too Much
The risk of developing licorice-induced hypertension is not consistent for everyone. Several factors influence how a person's body will react, including genetic predisposition, overall health, and the amount and duration of licorice consumption.
- Individual Sensitivity: Some individuals are more sensitive to glycyrrhizin's effects, and even small amounts can cause an adverse reaction. Case studies show that a daily intake of 100 mg of glycyrrhizin over just two weeks can significantly raise blood pressure in some healthy people.
- Duration and Dosage: While moderate, occasional consumption is generally considered safe for most healthy individuals, chronic, high-dose intake significantly increases the risk. The World Health Organization (WHO) has set a provisional daily limit of 100 mg of glycyrrhizin. However, the glycyrrhizin content in commercial tea products varies widely, making it difficult to monitor intake accurately.
- Pre-existing Conditions: Individuals with pre-existing conditions are at a much higher risk. This includes people with a history of hypertension, heart disease, kidney disease, or low potassium levels. Licorice consumption is also advised against during pregnancy.
Comparison: Standard Licorice Root vs. DGL Tea
If you enjoy the flavor of licorice root but are concerned about its effect on blood pressure, it is important to distinguish between regular licorice root tea and deglycyrrhizinated licorice (DGL) tea. This table highlights the key differences.
| Feature | Standard Licorice Root Tea | Deglycyrrhizinated Licorice (DGL) Tea |
|---|---|---|
| Key Compound | Contains glycyrrhizin | Has most of the glycyrrhizin removed during processing |
| Blood Pressure Risk | Can raise blood pressure due to glycyrrhizin's effects | Significantly reduces or eliminates the risk of raising blood pressure |
| Cardiovascular Side Effects | Potential for fluid retention, hypokalemia, and cardiac issues with excessive intake | Minimizes the risk of electrolyte imbalance and other cardiovascular side effects |
| Primary Use | Used for its flavor and traditional medicinal properties, including soothing sore throats | Most often used for gastrointestinal issues, like heartburn and ulcers, without the blood pressure risk |
| Safety Profile | Caution required, especially for at-risk groups and chronic use | Considered much safer for long-term use and for individuals with hypertension |
The Takeaway on Licorice Root and Blood Pressure
Ultimately, the connection between licorice root tea and elevated blood pressure is a well-documented scientific fact, not a myth. The mechanism is a clear biochemical process involving glycyrrhizin and its effect on mineralocorticoid receptors. For most healthy adults, occasional, moderate consumption is unlikely to cause issues. However, the risk increases with chronic use, high dosage, or the presence of underlying health conditions.
If you have concerns about your blood pressure or are on medication, it is essential to consult with a healthcare professional before adding licorice root tea to your daily routine. For those who want to avoid the risk entirely while still enjoying the potential digestive benefits of licorice, deglycyrrhizinated licorice (DGL) is a much safer alternative. Always be aware of what is in your herbal tea blends and check with a doctor if you experience any concerning symptoms. A balanced and informed approach is key to enjoying herbal remedies safely.
Conclusion
In summary, licorice root can raise blood pressure due to its active compound, glycyrrhizin, which disrupts hormonal and electrolyte balance in the body, mimicking a condition known as pseudohyperaldosteronism. This leads to sodium retention, potassium loss, and fluid buildup, collectively causing blood pressure to rise. While the effect is dose-dependent, individual sensitivity and pre-existing health conditions greatly influence the risk. Opting for DGL licorice or speaking with a healthcare provider is the safest course of action for anyone concerned about their cardiovascular health.
