(By Stephen Christensen, Livestrong.com) Valerian is a flowering perennial herb that is widely distributed in the northern hemisphere. Its root has been used for centuries as a mild sedative and sleep aid. While there are around 250 species in the Valeriana genus, V. officinalis is the species most commonly used in herbal remedies. Phyllis Balch, author of “Prescription for Herbal Healing,” reports that some of valerian’s constituents have been shown to lower blood pressure, but valerian has not been approved for treating high blood pressure. Consult your doctor before using valerian.
Valerian and Blood Pressure
Well-designed studies to evaluate valerian’s effects on high blood pressure are lacking. A small 2002 trial in “Phytotherapy Research” demonstrated that people who were subjected to stressful mental tasks exhibited milder heart rate and blood pressure increases when they took valerian before the tests. However, this study evaluated subjects with normal blood pressure, and the observed blunted stress response was limited to systolic blood pressure only. Diastolic blood pressure was unaffected.
Valerian as a Sedative
Although several studies have demonstrated valerian’s effectiveness as a sedative, the National Institutes of Health Office of Dietary Supplements, or ODS, states that this data is inconclusive due to inconsistencies in study design and high subject dropout — valerian has a disagreeable odor. Therefore, even if your blood pressure only increases when you are under stress, it is not clear if valerian will help. In its review, ODS discusses valerian’s active constituents and various potential mechanisms for the herb’s sedative properties, including its ability to increase the levels of gamma-aminobutyric acid, or GABA, in the brain.
GABA and Blood Pressure
GABA exerts a generalized calming effect on the central nervous system. It could be argued that valerian’s ability to increase brain levels of GABA accounts for its putative ability to lower blood pressure. A “European Journal of Clinical Nutrition” trial showed that GABA could lower blood pressure in mildly hypertensive people, but this study, which did not examine valerian directly, exhibited design flaws. Furthermore, valerian’s effects on GABA levels are not well-characterized, so it should not be assumed that valerian will lower blood pressure by increasing GABA levels.
Valerian’s status as a sedative, though questioned by some scientists, is well established among the herbal community….