Ginkgo biloba is an herbal supplement derived from one of the oldest tree species in the world. It is recognized for supporting general well-being, particularly cognitive function and circulatory health. Individuals often question its systemic effects, especially regarding blood pressure regulation. Understanding this relationship requires examining the scientific evidence concerning its direct action on blood vessels.
The Direct Answer: Ginkgo Biloba’s Effect on Blood Pressure
Research indicates that Ginkgo biloba does not cause an increase in blood pressure in healthy adults. When taken alone by individuals with normal blood pressure, the effect is neutral, showing no change in systolic or diastolic readings. Multiple clinical trials focusing on both short-term and long-term use confirm this finding.
Some studies focusing on pre-hypertensive animal models have observed a blood pressure-lowering effect. For example, one human study on pre-hypertensive adults showed a reduction in both systolic and diastolic blood pressure after three months of daily supplementation. This suggests the herb’s intrinsic effect aligns with vasorelaxation, not constriction. The long-term, large-scale Ginkgo Evaluation of Memory (GEM) study, involving thousands of elderly participants, concluded that the supplement did not reduce the incidence of hypertension, reinforcing its overall neutral effect.
How Ginkgo Biloba Influences Circulation
The neutral or mildly hypotensive effects of Ginkgo biloba stem from its influence on the body’s vascular system. The active components are primarily ginkgo flavone glycosides and terpene lactones, such as ginkgolides and bilobalides. These compounds contribute to vasodilation, improving blood flow.
The flavone glycosides possess antioxidant properties that help preserve the function of nitric oxide (NO), a molecule that signals blood vessels to relax. By protecting NO from breakdown, Ginkgo biloba helps maintain vessel wall elasticity and reduces peripheral vascular resistance. This mechanism explains why the supplement is studied for improving perfusion in various microcirculatory systems, including the cerebral, ocular, and cutaneous vascular beds.
Critical Interactions with Blood Pressure Medications
While Ginkgo biloba may not raise blood pressure on its own, its interaction with prescription medications represents a safety concern. Individuals taking antihypertensive drugs must exercise caution due to the possibility of altered drug metabolism. Certain constituents of the supplement can interfere with the cytochrome P450 (CYP450) enzyme system in the liver, which breaks down many medications.
This metabolic interference can lead to two opposing outcomes depending on the specific blood pressure medication. In some cases, the herb may reduce the effectiveness of a drug, such as losartan or nicardipine, by increasing its rate of metabolism and clearance from the body. Conversely, combining Ginkgo biloba’s mild vasodilatory properties with prescription reducers could potentiate their effects. This additive action can lead to an excessive drop in blood pressure, potentially causing severe dizziness, lightheadedness, or fainting.
A separate, high-risk interaction exists with anticoagulants and antiplatelet drugs, commonly known as blood thinners. Ginkgo biloba exhibits its own antiplatelet activity, reducing the ability of blood platelets to form clots. Combining this effect with pharmaceutical agents like warfarin, clopidogrel, or non-steroidal anti-inflammatory drugs (NSAIDs) increases the risk of bleeding. This heightened risk of hemorrhage makes concurrent use hazardous.
Safety and Consultation Guidelines
Anyone considering taking Ginkgo biloba, especially with a pre-existing cardiovascular condition, must discuss it with their healthcare provider first. Disclosing all supplements and herbal products is necessary to prevent complications with prescription drugs. A physician can assess the risk of interaction based on the individual’s current medication regimen and health status.
It is important to be aware of warning signs that warrant immediate medical attention. If these occur, stop taking the supplement and seek professional guidance immediately:
- Unexpected or easy bruising.
- Prolonged bleeding from cuts.
- The appearance of blood in the stool or urine.
- Severe or persistent dizziness, confusion, or syncope.
Following these guidelines ensures the safe use of Ginkgo biloba.