Bách khoa toàn thư - Dinh dưỡng và sức khỏe tốt - Vần V | V valerian root Valerian officinalis garden heliotrope setwall The root of a perennial herb native to Europe North America and northern Asia that has been used as a sleep aid and antianxiety treatment for more than 1 000 years. The plant is inconspicuous except for its small white or pink flowers and an unusual odor that some have described as reminiscent of aged cheese. According to legend the Pied Piper used valerian to lure rats from the village of Hamelin. Valerian is a popular dietary supplement in the United States and in Europe whose supporters claim it has a calming effect and can induce sleep. Reliable research to support these claims does not yet exist but the herb does appear to have some effect on the neurotransmitter gammaaminobutyric acid GABA . Small studies suggest effectiveness in promoting sleep compared to placebo. People with nerve disorders that causes uncontrollable spasms or who suffer from tardive dyskinesia have been found to have low levels of GABA in their brains. Because of the herb s reputation as an antispasmodic it has been used for centuries by women seeking relief from menstrual cramps. As a food valerian is classified generally recognized as safe. Because valerian root is available in the United States as an herb its safety and efficacy have not been tested by the . Food and Drug Administration fda . However in high doses valerian root rarely can cause liver damage with long-term use or high doses. Some patients who have taken the supplements have suffered chest pain heart arrhythmia tremors insomnia headache and blurred vision. With long-term high doses suddenly stopping valerian may be associated with a withdrawal syndrome. A few reports suggest possible decreased alertness after valerian use. Women who are pregnant or nursing should not take this supplement due to inadequate safety data. Garges P. et al. Cardiac Complications and Delirium Associated with Valerian Root Withdrawal Journal of the American Medical Association 280
