Common Plants That Can Increase Blood Pressure
While herbs and plants offer numerous health benefits, several contain active compounds that can have a stimulating or disruptive effect on the cardiovascular system, leading to an increase in blood pressure. It is critical for individuals with hypertension or those on related medications to be aware of these potential interactions.
Licorice Root (Glycyrrhiza glabra)
One of the most well-documented culprits, licorice root contains a compound called glycyrrhizin. When consumed in significant amounts, glycyrrhizin can inhibit the enzyme 11-beta-hydroxysteroid dehydrogenase type 2 in the kidneys. This enzyme typically inactivates the stress hormone cortisol, but its inhibition leads to excessive cortisol activity at the mineralocorticoid receptors. This process, known as pseudohyperaldosteronism, causes the body to retain sodium and water while excreting potassium, resulting in an increase in blood volume and, consequently, higher blood pressure. Even relatively small, daily doses have been shown to have a significant effect on blood pressure in healthy individuals. This effect is associated with black licorice, not red, which typically does not contain licorice extract.
Ephedra (Ma-huang)
Ephedra is a potent stimulant derived from the plant Ephedra sinica that contains the alkaloids ephedrine and pseudoephedrine. It was once a popular ingredient in weight-loss supplements and performance enhancers. These alkaloids act by stimulating the central nervous system, which leads to an increase in heart rate and constricts blood vessels, causing a rise in blood pressure. Due to the serious and sometimes fatal cardiovascular side effects, such as heart attack, stroke, and dangerously high blood pressure, the U.S. Food and Drug Administration (FDA) banned dietary supplements containing ephedrine alkaloids in 2004. Despite this ban, the herb may still be found in products marketed outside the US or under different names.
Ginseng (Panax species)
The effects of ginseng on blood pressure are complex and, at times, contradictory, often depending on the specific species and preparation. While some studies suggest certain ginseng varieties may help lower blood pressure over time, others show the opposite effect, particularly in high doses or with certain species like Asian ginseng (Panax ginseng). It is believed that ginseng's adaptogenic nature can cause a temporary rise in blood pressure, especially in those with pre-existing hypertension or when combined with other stimulants. The National Capital Poison Center advises that people with high blood pressure should not take Asian ginseng products without a doctor's supervision.
Bitter Orange (Citrus × aurantium)
Commonly used in weight-loss and appetite-suppressant products, bitter orange contains the stimulant synephrine. Synephrine is structurally similar to ephedrine and has similar effects on the body, increasing heart rate and blood pressure by stimulating adrenergic receptors. This poses a significant risk for individuals with hypertension, particularly when bitter orange is taken in combination with other stimulants like caffeine.
St. John's Wort
Best known for its use in treating depression, St. John's Wort has been associated with increased blood pressure and rapid heartbeat. Its potential to interact with multiple drugs, including those for blood pressure and antidepressants, makes it particularly dangerous. Combining it with SSRIs, for instance, can lead to life-threatening serotonin syndrome, which involves a rapid increase in blood pressure.
Yohimbe Bark
Derived from the bark of an evergreen tree native to Africa, yohimbe is sometimes used for erectile dysfunction or weight loss. The compound yohimbine found in the bark can increase blood pressure, heart rate, and nervousness. Yohimbe products are unregulated and inconsistent, and due to the significant risk of serious side effects like heart attack and seizure, it is best avoided, especially by those with hypertension.
Comparison of Plants That Raise Blood Pressure
| Plant (Scientific Name) | Key Compound(s) | Primary Mechanism | Associated Risk | FDA Status |
|---|---|---|---|---|
| Licorice Root (Glycyrrhiza glabra) | Glycyrrhizin | Inhibits cortisol inactivation, leading to sodium/water retention. | Fluid retention, hypokalemia, hypertension. | Regulated as a food additive, but caution advised. |
| Ephedra (Ephedra sinica) | Ephedrine alkaloids | Stimulates CNS, increases heart rate and constricts blood vessels. | Severe hypertension, heart attack, stroke, seizure. | Banned in dietary supplements. |
| Ginseng (Panax ginseng) | Ginsenosides | Can have biphasic effects; vasoconstriction at high doses. | Possible increase in blood pressure, variable effects. | Safe for some, but caution with Asian ginseng. |
| Bitter Orange (Citrus × aurantium) | Synephrine | Stimulant effect similar to ephedrine, increasing heart rate. | Hypertension, heart palpitations. | Commonly used, but safety concerns exist. |
| Yohimbe Bark (from Pausinystalia yohimbe) | Yohimbine | Stimulates nervous system, increases heart rate and blood pressure. | Severe hypertension, tachycardia, anxiety, seizures. | Significant safety concerns; best avoided. |
Risks of Self-Medicating with Herbs
Individuals who use herbal remedies for low blood pressure or other conditions without medical supervision face several risks. The dosage of active compounds can vary significantly between different products and batches, making it difficult to control the therapeutic effect. For those with pre-existing hypertension or other cardiovascular conditions, any unexpected increase in blood pressure can exacerbate their condition and increase the risk of serious events like heart attack or stroke. Moreover, the interactions between herbal supplements and prescribed medications are often not well-understood, leading to reduced drug efficacy or dangerous side effects.
A Crucial Reminder
Many natural products are not subject to the same rigorous testing and regulation as pharmaceutical drugs. The notion that 'natural' automatically means 'safe' is a dangerous misconception. The risk is particularly high when combining herbal stimulants or compounds that affect blood pressure with prescription medications for heart conditions or psychiatric disorders. Always consult a healthcare professional, especially a cardiologist or pharmacist, before starting any herbal supplement, particularly if you have a history of high blood pressure or are on medication. Informing your doctor about all supplements you take can help them manage your health more safely.
Conclusion
The belief that all plants are inherently safe for medicinal use is a common but dangerous myth, especially regarding blood pressure. Plants like licorice root, ephedra, ginseng, bitter orange, St. John's Wort, and yohimbe contain powerful compounds that can significantly and sometimes dangerously affect blood pressure levels. These substances can cause severe side effects, interfere with prescribed medications, and worsen existing cardiovascular conditions. Therefore, it is imperative for anyone considering herbal supplements, especially those with hypertension, to seek professional medical advice first to ensure their safety and well-being. A critical, evidence-based approach is essential when it comes to combining natural remedies and cardiovascular health management. A critical guide to herbs and your heart.
