The Evidence for Supplements and Hypertension

Nearly half of American adults now meet the criteria for having high blood pressure. Be ready for questions about supplements that might help. Here is what you can tell them.

The most recent hypertension guidelines continue to support taking oral potassium, and for good reason. Clinical evidence shows it can reduce systolic blood pressure (SBP) by about 3-9 mmHg and diastolic blood pressure (DBP) by about 2-6 mmHg in patients with or without hypertension, typically at doses around 2,500 mg daily. The guidelines specifically recommend aiming for 3,500-5,000 mg of dietary potassium per day, ideally through potassium-rich foods, though moderate-dose supplementation offers a reasonable alternative. However, it’s important to tell patients that taking potassium supplements with certain medications (e.g., ACE inhibitors, angiotensin receptor blockers, potassium-sparing diuretics) increases the risk of hyperkalemia.

But what about other supplements your patients may be curious about? While beetroot, berberine, and fish oil were not addressed in the new hypertension guidelines, research shows some promise.

Beetroot juice demonstrates slight benefits in healthy adults - reducing SBP by about 4 mmHg and DBP by 1 mmHg across multiple studies. However, current research shows that beetroot juice doesn’t lower blood pressure in patients with hypertension. And while most people handle beet consumption just fine, consuming large amounts might worsen kidney disease, due to beet’s oxaluric acid content, and caution is advised in those patients.

Berberine also offers promising results. In patients with hypertension, studies show additional reductions of SBP by about 5 mmHg and DBP by about 2 mmHg when berberine is added to a regimen of amlodipine. And while berberine is generally well-tolerated, patients should keep in mind common side effects such as abdominal pain, constipation, and diarrhea.

Fish oil is worth noting. Research shows it can provide modest blood pressure improvements, with a reduction in SBP by approximately 3-6 mmHg and DBP by about 2-4 mmHg, particularly in patients with moderate to severe hypertension when used alongside standard antihypertensive therapy. You might want to let patients know that fish oil is likely safe, but they should keep an eye out for that fishy aftertaste and heartburn.

While these supplements demonstrate potential for lowering blood pressure, tell patients that they are not substitutes for proven guideline-recommended therapies and to share all supplements they’re taking with their healthcare providers as this allows for proper monitoring of blood pressure.

For additional information on the efficacy and safety of these and other supplements, review the full monograph. Additionally, explore our “Effectiveness by Condition” tool to discover other evidence-based supplement options for blood pressure management.