What is the American Heart Association's (AHA) stance on using herbal supplements for heart health?

American Heart Association Position on Herbal Supplements for Heart Health

The American Heart Association does not recommend herbal supplements or isoflavone supplements for cardiovascular disease prevention or treatment, as clinical trials have failed to demonstrate clinically meaningful benefits and some supplements carry potential cardiovascular risks. 1

AHA's Evidence-Based Stance

Antioxidant Supplements: Not Recommended

• The AHA explicitly advises against using antioxidant supplements such as vitamin E and beta-carotene for heart disease prevention. 1
• Clinical trials have shown no cardiovascular benefit from these supplements, and some studies revealed an unexpected increase in hemorrhagic strokes. 1
• These supplements may interfere with the beneficial effects of statin therapy. 1

Soy Isoflavone Supplements: Not Recommended

• The AHA's 2006 Science Advisory specifically states that isoflavone supplements in food or pills are not recommended. 1
• Among 22 randomized trials of isolated soy protein with isoflavones, the average LDL cholesterol reduction was only 3%—a clinically insignificant effect relative to the large amounts tested (averaging 50g daily). 1
• Among 19 studies examining soy isoflavones alone, the average effect on LDL cholesterol and other lipid risk factors was nil. 1
• No significant effects were demonstrated on HDL cholesterol, triglycerides, lipoprotein(a), or blood pressure. 1
• The FDA stated that "evidence did not support a significant role for soy isoflavones in cholesterol-lowering effects of soy protein." 1

Limited Evidence-Based Supplement Recommendations

The AHA recognizes only two supplement categories with modest cardiovascular benefit:

Plant Stanols/Sterols:

• The AHA recommends plant stanols/sterols at 2 grams daily as a reasonable approach to further lower LDL cholesterol after initial dietary modifications. 2
• These achieve approximately 5-15% LDL reduction when added to a heart-healthy diet. 2

Soluble Fiber:

• The AHA recommends increasing fiber through whole foods rather than supplements, though psyllium fiber supplements are FDA-approved for cholesterol lowering. 2
• Consuming 10-25 grams of soluble fiber daily enhances LDL cholesterol lowering by 5-10%. 2

Omega-3 Fatty Acids: Food Over Supplements

• The AHA's 2004 guidelines listed omega-3 fatty acid supplementation as a Class IIb recommendation (lowest level of recommendation). 1
• For documented coronary heart disease, 1 gram of EPA+DHA daily is recommended, preferably from oily fish rather than supplements. 2

Safety Concerns with Herbal Supplements

Cardiovascular Adverse Effects

• Herbal supplements may cause serious cardiovascular adverse effects including arrhythmias, hypertension, hypotension, myocardial infarction, congestive heart failure, and death. 3, 4
• Herbal stimulants (bitter orange, ephedra, caffeine, guarana, maté, kola) are the most common category causing cardiovascular effects. 3
• Life-threatening adverse effects from herbs like aconite, ephedra, and licorice have been repeatedly documented. 4

Contamination and Adulteration Risks

• Herbal supplements may be contaminated with pesticides, heavy metals, bacteria, and pharmaceutical agents. 3
• "Herbal" products adulterated with prescription anorectics, antidepressants, diuretics, and phosphodiesterase-5 inhibitors have been identified throughout Europe, North America, and Asia—all with potential cardiovascular effects. 3

Herb-Drug Interactions

• Herbal ingredients may cause both pharmacokinetic and pharmacodynamic interactions with cardiovascular medications. 3, 4
• Many patients combine herbal ingredients with cardiovascular medications without informing their physicians. 3, 5

AHA's Recommended Approach to Heart Health

Instead of herbal supplements, the AHA prioritizes evidence-based interventions: 1

Class I Recommendations (Strongest Evidence):

• Smoking cessation 1
• Physical activity/cardiac rehabilitation 1
• Heart-healthy diet emphasizing fruits, vegetables, whole grains, fish, and lean proteins 1
• Weight maintenance/reduction 1
• Blood pressure control 1
• Cholesterol management with statins when indicated 1, 6
• Aspirin therapy for appropriate patients 1
• Beta-blocker and ACE inhibitor therapy for specific indications 1

Dietary Pattern Over Supplements

• The AHA's 2023 "Food Is Medicine" advisory emphasizes that heart-healthy dietary patterns contain primarily whole foods: fruits, vegetables, whole grains, liquid plant oils, and healthy protein sources. 1
• Many soy products should be beneficial to cardiovascular health because of their high content of polyunsaturated fats, fiber, vitamins, and minerals—not because of isoflavone content. 1

Clinical Practice Implications

What Physicians Should Do:

• Actively inquire about herbal supplement use, as patients often do not volunteer this information. 3, 5
• Educate patients that "natural" does not equal "safe" and that herbal supplements lack the rigorous testing required for prescription medications. 3, 4
• Emphasize that no supplement has cardiovascular outcomes data comparable to statins and other proven pharmacotherapy. 2
• When patients insist on supplements, limit recommendations to plant stanols/sterols (2g daily) and increased dietary fiber as adjunctive therapy only. 2

Critical Caveat:

Approximately 25% of herbal users do not take their prescribed cardiovascular medications regularly, believing herbs are sufficient. 5 This represents a major patient safety concern requiring direct physician intervention.