How Much Black Licorice Is Too Much? The Cardiologist’s Guide

Black licorice, a treat derived from the licorice plant (Glycyrrhiza glabra), has long been enjoyed for its distinct flavor and is often used in both candies and herbal remedies. However, despite its popularity, black licorice has a dark side, especially when it comes to your heart health. Overindulgence in black licorice can lead to a variety of health issues, including an irregular heartbeat, high blood pressure, and, in some cases, even heart failure.

This article will delve into the chemical properties of black licorice, particularly its main active ingredient, glycyrrhizin, and explain how it can impact cardiovascular health. We will also explore how much licorice is considered too much, who is most at risk, and what cardiologists and other healthcare professionals should know when advising patients about black licorice consumption.

What Is Black Licorice?

Black licorice is a confectionery flavor derived from the roots of the licorice plant. The plant has been used for centuries in traditional medicine, particularly in Eastern cultures, for its purported health benefits, such as soothing sore throats, reducing inflammation, and treating digestive issues. The primary active compound in licorice root is glycyrrhizin, which has sweetening properties, making it a key ingredient in candy and some medicines.

However, glycyrrhizin has effects on the body that go beyond just flavor enhancement. It influences the balance of potassium and sodium in the body, which, when disrupted, can have significant consequences on cardiovascular function, particularly heart rhythm.

The Chemical Culprit: Glycyrrhizin

The heart of the issue lies in glycyrrhizin, a potent chemical found in the licorice root. Glycyrrhizin exerts its effects by inhibiting the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which is responsible for the conversion of cortisol into its inactive form, cortisone. When this enzyme is inhibited, cortisol levels remain elevated, leading to effects similar to those caused by excessive aldosterone, a hormone that regulates sodium and potassium balance in the body.

This biochemical interaction can lead to a condition known as pseudoaldosteronism, which mimics the effects of having too much aldosterone. High levels of cortisol acting on mineralocorticoid receptors cause the kidneys to retain sodium and excrete potassium, resulting in:

• Hypokalemia (low potassium levels)
• Hypernatremia (high sodium levels)
• Hypertension (high blood pressure)

While these changes might seem minor, they can have significant consequences, especially on the heart.

How Black Licorice Affects the Heart

Potassium is an essential electrolyte that helps regulate muscle function, including the contractions of the heart. When potassium levels fall too low due to excessive black licorice consumption, the heart's electrical system can become disrupted, leading to arrhythmias — irregular heartbeats that can be mild or severe. In some cases, particularly in those who already have underlying heart conditions, arrhythmias can trigger serious cardiovascular events such as:

• Premature ventricular contractions (PVCs)
• Atrial fibrillation (AFib)
• Ventricular tachycardia
• Ventricular fibrillation

These irregular rhythms can cause dizziness, chest pain, shortness of breath, or even sudden cardiac arrest if not addressed promptly.

The Role of Glycyrrhizin in Hypertension and Heart Failure

In addition to causing hypokalemia, glycyrrhizin-induced sodium retention can lead to increased blood pressure. Chronic high blood pressure is a known risk factor for the development of heart disease, stroke, and heart failure. In individuals with pre-existing hypertension or other cardiovascular diseases, consuming black licorice may exacerbate these conditions and accelerate the progression of heart failure.

Patients with heart failure are already prone to fluid retention, and the sodium-retaining effects of glycyrrhizin can worsen this condition, leading to edema, shortness of breath, and decreased exercise tolerance. For this reason, patients with heart failure should be particularly cautious about consuming black licorice.

Who Is Most at Risk?

While anyone who consumes excessive amounts of black licorice is at risk for its adverse cardiovascular effects, certain populations are particularly vulnerable, including:

1. Older Adults: As we age, our kidneys' ability to regulate sodium and potassium becomes less efficient. Older adults are also more likely to be on medications that affect electrolyte balance or blood pressure. These factors make the elderly more susceptible to the effects of glycyrrhizin.
2. Patients with Cardiovascular Disease: Individuals with hypertension, heart failure, or arrhythmias are at higher risk of adverse effects from black licorice due to the licorice-induced changes in sodium and potassium levels.
3. Patients on Certain Medications: Medications such as diuretics, angiotensin-converting enzyme (ACE) inhibitors, and certain heart medications can interact with the effects of glycyrrhizin, further compounding the risks of hypokalemia and hypertension.
4. People with Kidney Disease: Since the kidneys play a crucial role in regulating electrolytes, those with compromised kidney function may have difficulty managing the sodium and potassium imbalance caused by black licorice consumption, putting them at higher risk of heart-related complications.

How Much Black Licorice Is Too Much?

The FDA has issued warnings about the risks of black licorice, stating that consuming just 2 ounces (about 57 grams) of black licorice a day for two weeks could be enough to cause serious health issues in individuals over 40, particularly those with underlying heart conditions.

This doesn’t mean that one needs to eliminate black licorice from their diet entirely. Occasional consumption in small amounts is unlikely to cause harm in healthy individuals. However, regular consumption of large quantities — especially among at-risk groups — should be avoided. It is important to note that glycyrrhizin can remain in the body for a prolonged period, so the effects of excessive licorice consumption may not subside immediately once intake stops.

What Should Cardiologists and Healthcare Providers Know?

Cardiologists and healthcare providers need to be aware of the potential cardiovascular risks associated with black licorice, especially when treating patients with heart disease, hypertension, or electrolyte imbalances. Understanding the link between glycyrrhizin and heart function can help in diagnosing patients who may present with unexplained arrhythmias or sudden-onset hypertension.

Here are a few key considerations for healthcare providers:

1. Ask About Dietary Habits: When evaluating patients with arrhythmias or worsening hypertension, cardiologists should inquire about the patient's diet, including their intake of black licorice and other licorice-containing products.
2. Educate Patients: Patients, especially those with existing cardiovascular conditions, should be educated about the potential dangers of consuming black licorice. They should be informed that even over-the-counter products like herbal teas and supplements may contain glycyrrhizin.
3. Monitor Electrolytes: For patients who regularly consume black licorice, electrolyte levels, particularly potassium, should be monitored. Any signs of hypokalemia should be addressed promptly, and patients should be encouraged to limit their licorice intake.
4. Be Aware of Drug Interactions: Certain medications, such as diuretics or medications that affect the renin-angiotensin-aldosterone system (RAAS), may interact with glycyrrhizin, compounding its effects. Providers should review patients’ medication regimens for possible interactions.

Black Licorice Alternatives: Deglycyrrhizinated Licorice (DGL)

For those who enjoy the flavor of licorice or use it for its medicinal properties but want to avoid the risks, deglycyrrhizinated licorice (DGL) is an option. This form of licorice has had the glycyrrhizin removed, reducing its impact on electrolyte balance and cardiovascular health. DGL is often used in herbal remedies and is considered safer for regular consumption.

Conclusion

While black licorice might be a nostalgic treat for some, it’s important to be aware of its potential health risks, particularly its effects on the cardiovascular system. The glycyrrhizin in black licorice can lead to hypokalemia, hypertension, and dangerous heart arrhythmias, especially in those who are predisposed to heart disease or other health conditions. Cardiologists and healthcare providers should educate their patients about the risks associated with black licorice and advise them to consume it in moderation, if at all.