Ginko Biloba

by

Ginko biloba tree leaf extract has been used as a major component of traditional Chinese medicine for thousands of years. Common names of ginko extract include ginko, ginko biloba, fossil tree, maidenhair tree, Japanese silver apricot, baiguo, and kew tree. Ginko biloba has historically been used to treat a multitude of symptoms and conditions, including respiratory conditions such as asthma and bronchitis, fatigue, and ringing in the ears (tinnitus). In more recent times, ginko biloba has been used to treat and prevent cognitive impairment, memory loss, Alzheimer’s disease, and other forms of dementia; to treat intermittent claudication (lower leg pain that results from the narrowing of the arteries); and to treat sexual dysfunction, multiple sclerosis, and a variety of other conditions.

Ginko biloba extract is most commonly consumed as a tablet, capsule, or as a tea, but can occasionally be found in topical skin products. When taken in oral form, ginko biloba is usually well tolerated in standard doses. It can cause side effects, however, including mild stomach upset, headache, dizziness, heart palpitations, constipation, and allergic skin reactions. Large doses have been shown to cause restlessness, diarrhea, nausea, vomiting, lack of muscle tone, and generalized weakness. Of notable concern is the risk of spontaneous bleeding, which is also a potential side effect of ginko biloba use. Various studies in a variety of settings and patient populations have suggested that ginko biloba may be related to episodes of minor to severe bleeding. It is important to note, however, that in many of these studies, no direct association between ginko biloba and the bleeding episode was made. Furthermore, in other studies, patients had other bleeding-associated risk factors that could not be ruled out. Nevertheless, ginko biloba should be used cautiously when taken in combination with other herbs that can impact blood clotting. Examples of these include angelica, clove, danshen, garlic, ginger, and Panax ginseng.

Ginko biloba may also have major interactions when used in combination with various prescription drugs used to prevent blood clotting. Examples of anti-clotting medications include aspirin, ibuprofen, clopidrogrel (Plavix), enoxaparin (Lovenox), heparin, indomethacin (Indocin), and warfarin (Coumadin), among others.

In addition, ginko biloba may decrease the effectiveness of the sedative alprazolam (Xanax), as well as cause hypomania (a pervasive, elevated, euphoric mood) when taken with the following combination of prescription and non-prescription compounds: fluoxetine (Prozac), buspirone (BuSpar), St. John’s wort, and melatonin. Ginko biloba may also impair insulin secretion and metabolism and therefore should be used with caution in individuals with Type 2 diabetes.

In addition, ginko biloba seeds contain a chemical known as ginkgotoxin, which can cause seizures when consumed in high doses. Therefore, individuals with a known seizure disorder, such as epilepsy, should not take products containing ginkgo biloba.

Ginko Biloba and Fibromyalgia

Limited research has been conducted to examine the role ginko biloba may have in treating fibromyalgia. One small, uncontrolled study was conducted in 2002 in an effort to measure the effects of combined therapy with ginko biloba and coenzyme Q10 in fibromyalgia patients. This study was undertaken in an effort to substantiate anecdotal reports of that suggested such a combination of therapies was useful in improving various fibromyalgia symptoms. In particular, the researchers sought to determine what, if any, impact a combination of ginko biloba and coenzyme Q10 had on quality of life measures. Each subject received 200mg of coenzyme Q10 and 200mg ginko biloba per day for a total of 84 days. Quality of life was measured via a validated questionnaire at baseline, and then again at four, eight, and 12 week intervals. The findings showed that patients experienced a progressive improvement in their quality of life scores over the course of the study. These improvements were supported by self-ratings from patients, in which 64% of patients self-rating themselves as improved by the end of the study, versus only 9% who claimed to feel worse (Lister, 2002).

Ginko Biloba and Cognitive Impairment

Despite the limited research related to ginko biloba and fibromyalgia, ginko biloba may still be of use to fibromyalgia patients, as it has shown possible effectiveness in treating a number of symptoms and conditions commonly associated with fibromyalgia. A large majority of ginko-related research centers on its role in preventing dementia, memory impairment, and cognitive functioning. Since many fibromyalgia patients experience cognitive impairment, or “fibro fog,” the research surrounding cognitive functioning may be of interest to many fibromyalgia patients. It is important to note, however, that much of the research has been conducted in healthy individuals who show no symptoms of impaired cognition; therefore, the results of these studies may not be applicable to individuals who are already experiencing cognitive difficulties.

There is ample research to suggest that ginko biloba may improve certain measures of cognitive functioning in healthy individuals. A 1999 study by Rigney et al. evaluated the acute use of ginko biloba on memory and psychomotor performance in 31 healthy volunteers (14 females and 22 males). This randomized, double-blind, placebo-controlled study (the “gold standard” for research study design when attempting to evaluate the effectiveness of a particular treatment) evaluated five different doses of ginko biloba. Each participant took each of the five doses for a period of two days, with a five day washout period (during which the participant took no ginko biloba) in between doses. On the first day of the study, prior to taking the first dose of ginko biloba, each participant completed a battery of tests designed to evaluate their memory ability, as well as measures of sleep, sedation, cognitive ability, attention, and behavior. The test battery was repeated daily at various intervals throughout the dosing schedule in order to measure the immediate effects of ginko biloba. The researchers found that ginko biloba improved cognition – in particular memory – among healthy volunteers. The response appeared to be most effective at a dose of 120mg (Rigney et al., 1999). Although limited by a very small sample size, an earlier study of ginko biloba in eight healthy female patients also found significant improvements in memory following treatment with 600mg of ginko biloba (Subhan & Hindmarch, 1984), and a more recent study also found improvements in memory among 24 healthy adults following consumption of 40mg ginko biloba (Polich & Gloria, 2001). A large-scale study conducted in 262 healthy older adults (age 60 and over) also found improvements in memory following ginko biloba supplementation (Mix & Crews, 2002). Another large study of 256 healthy, middle-aged volunteers found that a combination of ginko biloba and Panax ginseng produced a 7.5% improvement in various aspects of memory, including both short- and long-term measures (Wesnes et al. 2000). These findings were also supported by another study that investigated the effects of ginko biloba/Panax ginseng on memory (Scholey & Kennedy, 2002).

A 2000 investigation by Kennedy et al. evaluated the effects of acute dosing of ginko biloba in young, healthy volunteers using a similar trial design to that of the Rigney et al. study described above. Twenty volunteers received a series of various doses of ginko biloba, or a placebo (sugar pill). The cognitive performance of each participant was measured using a battery of tests at various time points throughout the dosing schedule. These researchers found sustained improvements in participants’ attention levels following doses of 240mg and 360mg (Kennedy et al. 2000).

Ginko Biloba and Premenstrual Syndrome

Many female fibromyalgia patients experience exacerbated symptoms associated with premenstrual syndrome (PMS). One study has suggested that ginko biloba supplementation may be able to significantly improve breast tenderness and psychological symptoms associated with PMS. Tamborini & Taurelle (1993) studies 165 women between the ages of 18 and 45 who had suffered from PMS for three consecutive menstrual cycles. For the purposes of the study, half of the women received a ginko biloba supplement and the other half received a placebo. Dosing was done over a period of two menstrual cycles, starting on the 16th day of the first cycle and continuing until the 5th day of the second cycle. Patients self-rated their symptoms on a daily basis, and study practitioners also rated them at clinic visits both before and after the treatment. The researchers found that ginko biloba was particularly effective in alleviating breast tenderness, and this finding was statistically significant when compared to those who received placebo. In addition, the researchers found that neuropsychological symptoms also improved with ginko biloba treatment (Tamborini & Taurelle, 1993).

Using a very similar study design to that of the Tamborini & Taurelle study, Ozgoli et al. (2009) recently evaluated the use of ginko biloba to treat PMS symptoms. In this randomized, placebo-controlled trial, the researchers randomized 90 female medical students to receive either 40mg of ginko biloba or a placebo, three times per day. At the end of treatment, the study found significant decreases in the severity of both physical and psychologic symptoms for both the ginko biloba and placebo groups. However, the decrease in severity of symptoms was significantly greater among those who received ginko biloba than among the placebo group. 

Ginko Biloba and Raynaud’s Phenomenon

Another frequent comorbidity experienced by fibromyalgia patients is Raynaud’s phenomenon. A small study conducted in 2002 investigated the use of ginko biloba to treat the symptoms of Raynaud’s phenomenon in patients with no known underlying cause of the condition. The study began with a two week assessment period during which patients recorded the frequency, severity, and duration of their Raynaud’s attacks in individual diaries. Any patient who was receiving pre-existing treatment for their Raynaud’s was asked to discontinue that treatment method during the study period. At the end of this initial two week period, patients were then randomized to receive either ginko biloba (120mg, three times per day) or a placebo. Patients were examined by study staff following two and four weeks of treatment, and then at the end of the 10 week treatment period. After analysis of the results, the researchers found that those patients who were treated with ginko biloba experienced a 56% decrease in the frequency of weekly attacks, versus a 27% decrease in the placebo group (Muir et al., 2002). Although this study was conducted in a small sample of patients, the findings suggest that ginko biloba may be useful in decreasing the frequency of Raynaud’s phenomenon attacks. In their discussion, the authors cite the need for larger studies to investigate the potential utility of ginko biloba as a treatment for Raynaud’s phenomenon.

Ginko Biloba and Anxiety

Depression and anxiety are common complaints among many fibromyalgia sufferers. One study has evaluated the use of ginko biloba to treat anxiety disorder. Woelk et al. (2007) launched a randomized, double-blind, placebo-controlled trial in 107 patients with anxiety disorder. Patients were randomized to receive daily ginko biloba doses of either 480mg or 240mg, or a placebo. The treatment period lasted for four weeks. The study found that ginko biloba was superior to placebo at improving symptoms of anxiety, tension, and aggression. Furthermore, the improvements appeared to be dose-related, with those receiving the 480mg showing the greatest improvements.

—————————————-

References

1.        Rigney U, Kimber S, Hindmarch I. The effects of acute doses of standardized Ginkgo biloba extract on memory and psychomotor performance in volunteers. Phytother Res. 1999;13:408-415.

2.        Subhan Z, Hindmarch I. The psychopharmacological effects of Ginkgo biloba extract in normal healthy volunteers. Int J Clin Pharmacol Res. 1984;4:89-93.

3.        Polich J, Gloria R. Cognitive effects of a Ginkgo biloba/vinpocetine compound in normal adults: systematic assessment of perception, attention and memory. Hum Psychopharmacol. 2001;16:409-416.

4.        Kennedy DO, Scholey AB, Wesnes KA. The dose-dependent cognitive effects of acute administration of Ginkgo biloba to healthy young volunteers. Psychopharmacology (Berl). 2000;151:416-423.

5.        Mix JA, Crews WD. A double-blind, placebo-controlled, randomized trial of Ginkgo biloba extract EGb 761 in a sample of cognitively intact older adults: neuropsychological findings. Hum Psychopharmacol. 2002;17:267-277.

6.        Wesnes KA, Ward T, McGinty A, Petrini O. The memory enhancing effects of a Ginkgo biloba/Panax ginseng combination in healthy middle-aged volunteers. Psychopharmacology (Berl). 2000;152:353-361.

7.        Scholey AB, Kennedy DO. Acute, dose-dependent cognitive effects of Ginkgo biloba, Panax ginseng and their combination in healthy young volunteers: differential interactions with cognitive demand. Hum Psychopharmacol. 2002;17:35-44.

8.        Tamborini A, Taurelle R. [Value of standardized Ginkgo biloba extract (EGb 761) in the management of congestive symptoms of premenstrual syndrome]. Rev Fr Gynecol Obstet. 1993;88:447-457.

9.        Muir AH, Robb R, McLaren M, et al. The use of Ginkgo biloba in Raynaud’s disease: a double-blind placebo-controlled trial. Vasc Med. 2002;7:265-267.

10.     Ozgoli G, Selselei EA, Mojab F, Majd HA. A randomized, placebo-controlled trial of Ginko biloba L. in treatment of premenstrual syndrome. J Altern Complement Med. 2009;15(8):845-851.

Woelk H, Arnoldt KH, Kieser M, Hoerr R. Ginkgo biloba special extract EGb 761 in generalized anxiety disorder and adjustment disorder with anxious mood: a randomized, double-blind, placebo-controlled trial. J Psychiatr Res. 2007;41:472-480.

Leave a Comment

{ 0 comments… add one now }

Google Analytics Alternative