Millions of people taking blood pressure medications are being advised to pay close attention to what they drink, as certain beverages may reduce the effectiveness of their prescriptions or even trigger harmful side effects. Medications such as ACE inhibitors, beta-blockers, and diuretics are essential for managing high blood pressure, a condition affecting over 16 million people in the UK, many of whom are unaware they have it.

For the millions relying on blood pressure medications, the choice of beverage can play a pivotal role in the effectiveness of their treatment. Medical experts are urging patients to be cautious, as certain drinks may not only undermine their medications but could also provoke adverse reactions. In the UK, where over 16 million people live with high blood pressure—many unknowingly—medications like ACE inhibitors, beta-blockers, and diuretics are vital for daily health management.

1. Some fruit juices

Grapefruit juice is one of the most well-known culprits. 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, it can block an enzyme called CYP3A4, which helps break down many blood pressure medications.

Among the notorious offenders is grapefruit juice, widely recognized for its potential to disrupt medication efficacy. Dr. Sabrina Islam, a cardiologist at Temple Health and an associate professor at the Lewis Katz School of Medicine, explains that grapefruit juice can inhibit the enzyme CYP3A4, crucial for breaking down many blood pressure drugs.

2. Alcohol

Other common fruit juices, such as apple and orange, might also hinder the absorption and metabolism of certain blood pressure medications, notes Dr. David Maron from Stanford Medicine’s Preventive Cardiology Clinic. His observations urge caution among patients who regularly consume these beverages.

3. Caffeinated beverages

Alcohol presents another significant concern, particularly in combination with blood pressure medications like beta-blockers and ACE inhibitors. This interaction can dangerously lower blood pressure, leading to symptoms such as dizziness, fainting, and a rapid heartbeat. Alcohol’s potential to elevate blood pressure further complicates its relationship with medication. Dr. Maron advises moderation, recommending a maximum of one drink per day for women and two for men.

4. Licorice tea

Liquorice tea contains glycyrrhizic acid, which can significantly raise blood pressure and cause dangerous interactions with antihypertensive medications, even if consumed in small amounts. It acts by causing sodium retention and potassium loss, which reduces the effectiveness of blood pressure drugs. 

5. Herbal teas and supplements

Certain herbal products, such as St. John’s wort, ginseng, ephedra, yohimbine, liquorice root, and high-dose green tea extracts, may interfere with how the body processes blood pressure drugs. These interactions can reduce the effectiveness of medications or trigger side effects such as dizziness, irregular heart rhythms, or low potassium levels.

6. High-sodium vegetable juices 

While some vegetable juices can help lower blood pressure, such as celery, beetroot, or leafy green blends, those that are high in sodium can actually counteract blood pressure medications, particularly diuretics, ACE inhibitors, and ARBs, potentially leading to increased blood pressure, swelling, and reduced drug effectiveness. 

According to Blood Pressure UK, high blood pressure is the third largest risk factor for disease in the UK, after smoking and poor diet.

Experts have warned that patients taking blood pressure medications should speak with their healthcare provider before consuming these beverages to ensure their treatment remains safe and effective.