If you take blood pressure medications like ACE inhibitors or beta-blockers, your doctor has likely warned you to avoid certain things—including some beverages.
While blood pressure medications are generally effective at lowering the risk of heart attacks and strokes, certain drinks, like herbal teas and juices, can interfere with how they work or trigger unwanted side effects.
Health asked three cardiologists which beverages people shouldn’t drink while taking blood pressure medications. Here’s what they had to say.
Perhaps the most well-known interaction is with grapefruit juice. According to Sabrina Islam, MD, MPH, a cardiologist at Temple Health and an associate professor of medicine at the Lewis Katz School of Medicine at Temple University, the drink inhibits an important enzyme called CYP3A4, which helps metabolize and break down many blood pressure medications.
“Drinking excessive amounts of grapefruit juice can, in turn, lead to higher levels of these medications in the bloodstream, which can cause episodes of low blood pressure,” Islam said.
Other fruit juices, including apple and citrus ones like orange, may also affect how your body absorbs and processes certain blood pressure medications, said David Maron, MD, a cardiologist with the Preventive Cardiology Clinic at Stanford Medicine.
If you take blood pressure medication and regularly drink beer, wine, or cocktails, you may want to reconsider. Alcohol can enhance the effects of certain blood pressure drugs, including nondihydropyridine calcium channel blockers, alpha blockers, and beta-blockers, and may lead to significant drops in blood pressure, Islam said.
Alcohol may also worsen the side effects of these medications, including dizziness, lightheadedness, fainting, and changes in heart rate, according to the National Institute on Alcohol Abuse and Alcoholism.
On top of that, alcohol itself can raise your blood pressure—potentially offsetting the benefits of your medication. Just more than two drinks for men or more than one for women can be enough to have that effect, Maron said.
Caffeine can also diminish the effectiveness of blood pressure medications. Research shows that beta-blockers and diuretics don’t work as well when caffeine enters the mix.
Maron recommends limiting caffeine intake to less than 400 milligrams (mg) per day, roughly the amount in three cups of coffee. For reference, a cup of tea generally contains 35 mg of caffeine, while some energy drinks contain up to 250 mg per serving.
Even in small amounts, licorice tea and drinks containing glycyrrhizin—a flavorful chemical found in licorice root—can dramatically increase blood pressure and counteract the effects of blood pressure medications, research shows.
This happens because glycyrrhizin inhibits a kidney enzyme that normally converts active cortisol into its inactive form, cortisone, Maron explained. As a result, cortisol can build up in the body. “High cortisol levels lead to sodium retention, potassium loss, blood volume expansion, and high blood pressure,” he said.
Many herbal products can alter how your body processes, absorbs, or clears blood pressure drugs.
For example, St. John’s wort can interfere with how medicines are metabolized in the liver, while ginseng and ephedra may raise your heart rate and blood pressure, according to Harlan Krumholz, MD, SM, a cardiologist with Yale Medicine.
“These interactions may blunt the medication’s effect or cause side effects such as dizziness, low potassium, or abnormal heart rhythms,” he said.
In addition to St. John’s wort, ginseng, and ephedra, Kumbolz recommends avoiding yohimbine and high-dose green tea extract.
Certain commercial vegetable juices can increase sodium levels and cause the body to retain fluid. This buildup can strain blood vessels and directly raise blood pressure, Krumholz said. As a result, high-sodium vegetable juices may reduce the benefits conferred by medications like diuretics, ACE inhibitors, and angiotensin receptor blockers (ARBs).
When that happens, “people may experience swelling, higher blood pressure readings, or reduced effectiveness of their prescribed drugs,” Krumholz said.
All told, recommendations can vary based on your individual blood pressure, underlying health conditions, and the specific medication you’re taking. If you’re unsure whether a beverage might interfere with your treatment, it’s best to speak with a health professional.
“A doctor or pharmacist can help tailor advice and ensure safe choices, because what’s risky for one person may be acceptable for another,” Krumholz said.
