Ginkgo biloba, one of the oldest trees known, first appeared in the Jurassic age, before flowering plants. Its admirable survival skills through time have given ginkgo a place in the arsenal of traditional herbal medicines, which attribute ginkgo with significant health benefits. Scientific research has supported some health benefits for ginkgo, with varying results for others, including lowering blood pressure. Consult your doctor before using ginkgo to treat high blood pressure.
Long-Term Study
Ginkgo biloba was not effective at lowering blood pressure in a study of over 3,000 elderly patients, published in the May 2010 "American Journal of Hypertension." Participants in the study, whose average age was 79 years, were followed over a six-year period of time. At the start of the study, 54 percent had high blood pressure, 28 percent were pre-hypertensive and 17 percent had normal blood pressure. The researchers found that the hypertension rate did not differ between the group that took ginkgo and the control group, over the time period of the study.
Heart Rate
Ginkgo biloba reduced heart rate and velocity of blood flow but did not reduce blood pressure, according to a study on laboratory animals published in the January 2008 "Biological Pharmaceuticals Bulletin." Scientists gave the animals a diet consisting of 0.5 percent ginkgo biloba extract for four weeks. Liver enzymes increased significantly with ginkgo biloba supplementation, as well. The researchers concluded that long-term use of ginkgo biloba extract impaired peripheral circulation by slowing the heart.
Liver Blood Pressure
Liver blood pressure decreased in response to ginkgo biloba supplementation, according to a study published in the April 2007 issue of "Chinese Journal of Hepatology." In the study, ginkgo supplementation in animals for 10 weeks resulted in a 15 percent drop in blood pressure in the portal vein -- the blood vessel that brings blood from the digestive tract to the liver -- and increased circulation within the liver. Levels of oxidized lipids were decreased by the ginkgo extract, and other markers for oxidative stress were similarly improved.
Systolic Blood Pressure
Long-term supplementation with ginkgo biloba extract significantly decreased systolic blood pressure -- the upper number of the blood pressure ratio, in a study published in the February 2006 "Journal of Pharmacy and Pharmacology." The study on laboratory animals used diets containing 0.05 percent to 0.5 percent ginkgo extract for 30 days. Hypertensive animals showed significant decreases in systolic blood pressure, and a relaxation response to the neurotransmitter acetylcholine was induced in the hypertensive group but not in a control group that did not have hypertension. The researchers concluded that ginkgo biloba acted on the inner layer of the arteries to promote dilation and lower blood pressure.
References
- "American Journal of Hypertension"; Effect of Ginkgo Biloba on Blood Pressure and Incidence of Hypertension in Elderly Men and Women; T. Brinkley, et al.; 2010
- "Biological and Pharmaceutical Bulletin"; Long-term Feeding of Ginkgo Biloba Extract Impairs Peripheral Circulation and Hepatic Function in Aged Spontaneously Hypertensive Rats; Y. Tada, et al.; 2008
- "Chinese Journal of Hepatology"; The Effect of Ginkgo Biloba Extract on Portal Hypertension and Hepatic Microcirculation in Rats]. [Article in Chinese] C. Zhang, et al.; 2007
- "Journal of Pharmacy and Pharmacology"; Effects of Ginkgo Biloba Extract on Blood Pressure and Vascular Endothelial Response by Acetylcholine in Spontaneously Hypertensive Rats; Y. Kubota, et al.; 2006
