Herbal or Dietary Supplement Use and Hypertensive Medications: Does the Combination Relate to Medication Adherence and Blood Pressure Control?

Medication nonadherence contributes to poor blood pressure control and increases cardiovascular disease risk in patients with hypertension. Identifying modifiable risk factors for low or nonadherence to antihypertensive medication is needed. Studies that have examined the relationship between herbal or dietary supplement (HDS) use and antihypertensive medication nonadherence provide inconsistent findings. Data from the National Health and Nutrition Examination Survey were used to examine the association between HDS use, current use of prescribed antihypertensive medication, and blood pressure status. The study sample included hypertensive adults ( = 5,478) who have been told by a health professional to take prescribed medication for their health condition. Respondents were classified as either HDS users or HDS nonusers. Depending on the kind of supplement used, HDS users were further divided into three mutually exclusive groups: hypertension HDS users, nonhypertension HDS users, and those who used both kinds of supplements. Supplements groupings were based on reports in the literature. Blood pressure status definition was based on Eighth Joint National Committee (JNC 8) recommendations. Adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were obtained from logistic models. Overall HDS use prevalence was 62%. Current medication use did not significantly differ between patients reporting no HDS use and those reporting HDS use (aOR: 1.45; 95% CI: 0.78-2.69). No observable differences were found in current medication use between patients reporting no HDS use and those taking nonhypertension HDS or both kinds of supplements. Use of hypertension HDS was associated with improved blood pressure (aOR: 1.90; 95% CI: 1.07-3.36) compared with no HDS use. In a nationally representative U.S. sample, HDS use did not compromise current use of prescribed medication and was associated with improved blood pressure control. More research is needed to better understand why HDS use is associated with better blood pressure control.