Ginkgo

Ginkgo is derived from the leaves of the ginkgo tree (commonly planted for ornamental purposes). The leaves contain numerous biologically active substances, such as ginkgolides and flavonoids. Ginkgo is one of the most commonly used herbal supplements.

The fruit of the ginkgo tree is not used in ginkgo products because of its bad smell. Contact with the fruit pulp, which may be encountered under female ginkgo trees, can cause severe skin inflammation (dermatitis). The seeds of the fruit are toxic and can cause seizures and, in large amounts, death. Sometimes less expensive ingredients are used to make poor-quality ginkgo more satisfactory to consumers. Not all tests can detect the poor-quality product, so such products may still be available.

(See also Overview of Dietary Supplements Overview of Dietary Supplements Dietary supplements are used by about 75% of Americans. They are the most common therapies included among integrative medicine and health (IMH) and complementary and alternative medicine (CAM)... read more .)

Ginkgo reduces the clotting tendency of particles in the blood that help stop bleeding (platelets), dilates blood vessels (thereby improving blood flow), and reduces inflammation. People take ginkgo for many reasons, such as improving blood flow to the lower legs when there is atherosclerotic vascular disease of the arteries in the legs (peripheral arterial disease Overview of Peripheral Arterial Disease Peripheral arterial disease results in reduced blood flow in the arteries of the trunk, arms, and legs. Most often, doctors use the term peripheral arterial disease to describe poor circulation... read more ); treating dementia (as in Alzheimer disease Alzheimer Disease Alzheimer disease is a progressive loss of mental function, characterized by degeneration of brain tissue, including loss of nerve cells, the accumulation of an abnormal protein called beta-amyloid... read more ), type 2 diabetes Type 2 diabetes Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Symptoms of diabetes may... read more , age-related macular degeneration Age-Related Macular Degeneration (AMD or ARMD) Age-related macular degeneration (AMD) causes progressive damage to the macula, the central and most vital area of the retina, resulting in gradual loss of central vision. Central vision becomes... read more (an eye disease), ringing in the ears Ear Ringing or Buzzing Ringing in the ears (tinnitus) is noise originating in the ear rather than in the environment. It is a symptom and not a specific disease. Tinnitus is very common—10 to 15% of people experience... read more (tinnitus), and altitude sickness Altitude Illness Altitude illness occurs because of a lack of oxygen at high altitudes. Symptoms include headache, tiredness, nausea or loss of appetite, irritability, and in more serious cases, shortness of... read more ; and preventing kidney damage caused by the drug cyclosporine.

Scientific studies show ginkgo benefits people with peripheral arterial disease, although the benefit is minor. Ginkgo increased the distance that affected people could walk without pain.

Meaningful benefits for people with dementia seem unlikely based on findings from a large clinical trial. In this clinical trial, ginkgo was not effective in reducing the development of dementia and Alzheimer disease in older people. However, other studies indicate that ginkgo, when taken at sufficient doses and for more than 5 months, can temporarily stabilize mental and social function in people with mild to moderate dementia.

For various health conditions, a small amount of evidence suggests a benefit from taking ginkgo. Ginkgo may

Emerging evidence reports the benefit of ginkgo in treatment of type 2 diabetes Type 2 diabetes Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Symptoms of diabetes may... read more . When combined with metformin, ginkgo significantly decreased fasting glucose and HbA1C.

Nausea, digestive upset, headache, dizziness, and heart palpitations may occur in people who take ginkgo. It should not be used by pregnant women because it may lead to early labor or excessive bleeding during childbirth. Gingko also should be stopped at least 2 weeks before surgery because of the potential for excessive bleeding.

Ginkgo may interact with drugs that prevent blood clots (such as warfarin), aspirin, and other nonsteroidal anti-inflammatory drugs (NSAIDs). Ginkgo may also reduce the effectiveness of antiseizure drugs Antiseizure drugs In seizure disorders, the brain's electrical activity is periodically disturbed, resulting in some degree of temporary brain dysfunction. Many people have unusual sensations just before a seizure... read more and antidepressants that affect serotonin (such as the SSRIs Selective serotonin reuptake inhibitors (SSRIs) Several types of medications can be used to treat depression: Selective serotonin reuptake inhibitors (SSRIs) Norepinephrine-dopamine reuptake inhibitors, serotonin modulators, and serotonin-norepinephrine... read more and SNRIs Norepinephrine-dopamine reuptake inhibitors, serotonin modulators, and serotonin-norepinephrine reuptake inhibitors Several types of medications can be used to treat depression: Selective serotonin reuptake inhibitors (SSRIs) Norepinephrine-dopamine reuptake inhibitors, serotonin modulators, and serotonin-norepinephrine... read more ).

Ginkgo is relatively safe and provides a small benefit for people with peripheral arterial disease and possibly various other health conditions. People taking drugs that may interact with ginkgo should consult with their doctor before taking ginkgo supplements. It is also important to stop using ginkgo 2 weeks before surgery.