Ginkgo Biloba is a highly popular tree native to China that is often cultivated for use as both a food source and dietary supplement. Some fossil evidence suggests that Ginkgo has been utilized for over 270 million years. Various temples in China are noted to have very old Ginkgo trees, some of which were planted over 1,500 years ago.
In other areas, Ginkgo trees are said to be over 2,500 years old – making them among the longest living trees on Earth. The longevity of the Ginkgo is due to the fact that: it contains a deep root system, its wood is impervious to insect penetration, and it has a low likelihood of becoming diseased. The Ginkgo tree is relatively large, peaking at heights often exceeding 110 feet.
While the Ginkgo is highly popular in China, its popularity has increased in Japan and Korea. Most people in the United States have heard of Ginkgo Biloba, and certain people consider it a nootropic supplement. Ginkgo supplements have been marketed to: enhance memory, lengthen attention span, lower blood pressure, and improve cognitive function – unfortunately not all of these allegations are supported by science.
Ginkgo Biloba Mechanism of Action (How It Works)
The precise mechanism of action associated with Ginkgo Biloba supplementation isn’t well understood. Many suspect that Ginkgo’s mechanism of action is complex and stems from specific bioflavonoids, flavonoids, proanthocyanidins, and trilactonic diterpenes (ginkgolide A, B, C). The combination of bioflavonoids, flavonoids, proanthocyanidins – has been noted to: increase blood flow (to tissues and organis), reduce oxidative damage (scavenging free radicals), and inhibit platelet activating factor (PAF).
It is hypothesized that Ginkgo elicits an anti-inflammatory effect via effects on platelet activating factor (PAF) and altering the infiltration of white blood cells. By acting as an antagonist to platelet activating factor while simultaneously decreasing infiltration of eosinophil and neutrophil, inflammation is theorized to decrease. In addition, Ginkgo is thought to function as an antioxidant by scavenging free radicals, most notably nitric oxide.
Ginkgo is also capable of improving the brain’s ability to metabolize glucose by enhancing the production of ATP. From a neurotransmission perspective, supplementation may increase activation of Alpha-2 adrenergic receptors and inhibit activation of COMT (Catechol-O-methyltransferase). In other words, Ginkgo may be slowing the enzymatic breakdown of certain neurotransmitters such as dopamine, epinephrine, and norepinephrine.
Research has demonstrated central and peripheral effects from Ginkgo, including: neurophysiological, electrical (brain waves), and vascular alterations in both animals and humans. Due to Ginkgo’s complex mechanism of action and widespread effects, many have theorized that it could be used to treat a variety of conditions including: dementia, memory impairment, or other cognitive deficits.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/10807109
Ginkgo Biloba Benefits & False Claims (Scientific Research)
Ginkgo Biloba is a highly popularized supplement and is often touted as having the ability to: improve memory, prevent age-related cognitive decline, and reverse symptoms of dementia. Moreover, many claim that Ginkgo can reduce vertigo, treat high blood pressure, cure tinnitus, improve eyesight, decrease altitude sickness, and expedite post-stroke rehabilitation efforts. Despite this herb’s mystique and widespread popularity as a supplement, many of the therapeutic claims associated with Ginkgo Biloba have been debunked by science.
ADHD: Many people with ADHD (attention-deficit/hyperactivity disorder) are in search of Adderall alternatives. Using a potent pharmaceutical drug that acts as a dopamine reuptake inhibitor (DRI) can have long-term consequences in terms of neurotransmitter levels, receptor densities, and physiological functioning. One natural supplement that has been hypothesized to help individuals with ADHD is Ginkgo Biloba.
2014: Some people regard Ginkgo as a complementary or alternative medical treatment (CAM) for attentional deficits. In 2014, researchers published a study analyzing the effects of Ginkgo Biloba Extract (EGb 761) among children diagnosed with ADHD based on DSM-IV criteria. The researchers specifically analyzed changes in the children’s neuroelectrical activity (brain waves) based on an EEG (electroencephalograph) reading.
This was considered an open-label “pilot study” involving 20 children with ADHD, all of whom were given EGb 761. The EGb 761 was titrated up to 240 mg daily until attention problems improved. Assessments were administered to determine the effect of EGb 761 and included: a clinical assessment, quality of life (QoL) scale, performance and prepatory brain-electrical activity during a Continuous Performance Test (CPT).
Results suggested subtle improvements in quality of life (QoL), core ADHD symptoms, and improvement on the Continuous Performance Test (CPT). Researchers suggest that administration of EGb 761 (up to 240 mg) may be effective among children with ADHD. That said, it is important to note that this is a small-scale pilot trial, and further research is warranted before definitive conclusions can be drawn.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/25163996
Cognitive function: There appears to be mixed-evidence regarding the efficacy of Ginkgo Biloba for the enhancement of cognitive function. In the early 2000s, a couple small-scale studies found that single-dose (acute) administration improved cognitive function, particularly attention speed and certain aspects of memory. However, a review of evidence in 2007 debunked these small-scale findings, highlighting the fact that Ginkgo Bioloba is unlikely to enhance cognitive function – regardless of whether it was administered acutely (single-dose) or consistently over a long-term.
2000: A study published in 2000 analyzed the acute effects of Ginkgo Biloba administration on cognitive function. At the time, researchers had thought that chronic supplementation over a long-term was an effective cognitive enhancer, but sought to further understand the effects of acute, short-term administration. The study conducted was considered a placebo-controlled, double-blind, and multi-dose trial.
Twenty (20) participants were recruited for the study and were assigned to receive Ginkgo at one of three doses (120 mg, 240 mg, 360 mg) or a placebo. Researchers measured their cognitive function prior to Ginkgo supplementation as well as 1, 2.5, 4, and 6 hours post-administration. Cognitive measures included: attention speed, attention accuracy, memory speed, and accuracy of memory.
Results demonstrated that Ginkgo was able to significantly improve cognitive measures, especially speed of attention. There appeared to be a dose-dependent relationship with higher doses of 240 mg and 360 mg producing the greatest degree of improvement for the longest duration (post-administration). Authors concluded that acute supplementation of Ginkgo enhances cognitive performance.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/11026748
2000: A study published in 2000 determined the effect of Ginkgo Biloba extract (EGb 761) among normal individuals with no history of cognitive dysfunction. The study was carried out over a short-term of 6 weeks and included 40 participants (between 55 and 86 years of age). In addition, the design was considered double-blind, placebo-controlled, and fixed-dose.
Participants were assigned to receive 180 mg per day of Ginkgo Biloba (EGb 761) or a placebo. A neuropsychological test was administered at pre-treatment baseline and just before the end of the 6 week treatment span. Results indicated that individuals receiving EGb 761 performed significantly better on processing speed compared to those receiving the placebo.
In several other measures, those receiving the EGb 761 performed better than the placebo, but the degree wasn’t statistically significant. This study provides some evidence to suggest that the Ginkgo extract EGb 761 could enhance cognitive function among adults with normative cognition.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/10890330
2002: In 2002, researchers published a study documenting the effect of single-dose Ginkgo Biloba, Panax Ginseng, and the combination of both. In the past, both had been shown to improve various aspects of cognitive function, especially among healthy young volunteers. Measures for this study included: cognitive performance (with a cognitive battery assessment) and mood (with Bond-Lader visual analogue scales).
The study was considered a randomized, placebo-controlled, double-blind trial and incorporated 20 participants. The participants were set to receive one of the following: Ginkgo 360 mg, Ginseng 400 mg, Ginkgo/Ginseng (combination) 960 mg, or a placebo. Baseline measures (cognition and mood) were documented and then compared to assessments at intervals following administration (1, 2.5, 4, and 6 hours).
Both Ginkgo and Ginseng were documented as improving various aspects of cognitive function on the assessment battery. The Ginkgo was reported as improving certain measures of mood based on a self-reported mood assessment. This provides further evidence in support of the idea that Ginkgo improves certain aspects of cognition.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/12020739
2004: The extract EGb 761 (derived from Ginkgo Biloba) was evaluated over a 4-week term to determine whether it could improve mental health and quality of life in healthy individuals. This evaluation was considered randomized, placebo-controlled, and double-blind and incorporated a total of 66 healthy volunteers (ages 50 to 65). Participants were assigned to receive either 240 mg of EGb 761 (34 individuals) or a placebo (32 individuals).
Researchers assessed adherence to supplementation and safety at intervals of 1, 2, 3, and 4 weeks. Recordings were taken of subjective mental health (self-reports), general health (GH), and quality of life (QoL). Results indicated that those receiving EGb 761 reported significant improvements in mental health and quality of life compared to the placebo group – suggesting therapeutic benefit.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/14602503
2007: A systematic review was published in 2007, expanding upon an earlier review of evidence published in 2001. In this review, researchers included data from an extensive body of research to determine whether Ginkgo Biloba is effective for cognitive enhancement in healthy volunteers. They looked for randomized, placebo-controlled, and double-blinded trials studying the effect of Ginkgo Biloba on cognitive function.
A total of 15 randomized clinical trials were incorporated in the research, all of which recruited healthy participants under 60 years of age. Of the 15 trials, 7 were considered “single-dose” and 8 were “longer term” (up to 13 weeks). The review of evidence found problems with much of the research, including the fact that findings are contradicted by other studies and/or aren’t easily replicated.
Of the 8 longer-term trials, there appears to be minimal evidence suggesting efficacy of Ginkgo Biloba as a cognitive enhancer. Only one study reported “subjective improvement” and another reported “positive results.” In other words, there is insufficient evidence to conclude that Ginkgo Biloba enhances cognitive function in healthy individuals – regardless of whether administered acutely or over a long-term.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/17480002
Driving Performance: Some researchers have hypothesized that taking Ginkgo Biloba could improve driving performance. Since the supplement is known to improve cognitive function and attention span, they speculate that it may improve ability to operate a motor vehicle. Preliminary evidence suggests no significant performance enhancing benefit is derived from Ginkgo in regards to operation of a motor vehicle.
2015: In recent years, researchers decided to investigate the potential performance enhancement effect of Ginkgo Biloba. Many studies have suggested that Ginkgo may improve aspects of cognitive function and alertness. To take things further, researchers set up a driving performance test and determined whether a mixed herbal supplement of Ginkgo and Ginseng enhanced driving ability.
A total of 30 participants engaged in the study and were assigned to receive either Ginseng, Ginkgo, or a placebo – 10 minutes after a simulated driving task. About one hour after taking either a placebo or the herbal supplements, another 10 minute simulated driving task was assigned. The test measured reaction time, attention, and lateral positioning on the road.
There was no significant difference in driving ability between those receiving Ginkgo, Ginseng, or a placebo. Despite no significant differences, researchers believe that the results may be unreliable due to the small sample size.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/25597699
High Blood Pressure: Another common claim associated with Ginkgo Biloba supplementation is that it can treat hypertension (high blood pressure). Throughout China and Europe, many individuals resort to taking Ginkgo in effort to reduce their blood pressure. That said, there isn’t much evidence suggesting that its effective for hypertension and its safety profile hasn’t been fully investigated.
In 2014, researchers conducted a review of evidence incorporating 9 randomized controlled trials (RCTs) with a total of 1,012 individuals diagnosed with hypertension. Of these 9 trials, 6 determined that Ginkgo Biloba Extract (GBE) had positive effects on blood pressure when used as a complementary therapy. In the remaining 3 trials, Ginkgo supplementation was unable to reduce blood pressure.
This review suggests that the efficacy of Ginkgo Biloba to treat high blood pressure remains undetermined. Although the supplement was effective as a complementary therapy, this doesn’t imply efficacy as a standalone treatment for hypertension. There are clearly more effective options both pharmaceutical and natural for treating hypertension.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/24877716
Memory enhancement: It appears as though using Ginkgo Biloba combined with Panax Ginseng may enhance memory when taken over a long-term. A study conducted in 2000 determined that memory improved by over 7% when a combination of these herbs was taken. A separate study conducted in 2004 suggested no beneficial long-term therapeutic effect on memory was derived from Ginkgo or Ginseng.
Additional research conducted with a specific extract of Ginkgo called “EGb 761” noted significantly enhanced memory as a result of supplementation. Since evidence is mixed regarding Ginkgo’s ability to enhance memory, no definitive conclusions can be drawn from the research regarding efficacy.
1999: A study conducted in the 1990s determined whether acute doses of Ginkgo Biloba extract could improve psychomotor performance and memory in middle-aged adults. The study was considered double-blind, randomized, and placebo-controlled and included 31 participants (30 to 59 years of age). The 31 participants were assigned to receive varying doses of Ginkgo Biloba extract or a placebo for 2 days.
Psychometric assessments were performed prior to dosing and then at various intervals after dosing. This study determined that Ginkgo Biloba extract can improve cognitive function in healthy volunteers, with a hypothesized dose-dependent relationship. Most specifically was enhancement of working memory at 120 mg.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/10441781
2000: A study published in 2000 documented the effects of Ginkgo Biloba (GK501) at 60 mg and Panax Ginseng (G115) at 100 mg on cognitive function. This double-blind, placebo-controlled study was conducted on a group of 256 middle-aged volunteers over a term of 14 weeks. Assessments were administered to determine attention and memory function using a computerized Cognitive Drug Research protocol.
The cognitive assessments were conducted at baseline (pre-study), and again at Weeks 4, 8, 12, and 14. In addition, measures were taken at various hourly intervals of 1, 3, and 6 hours post-dosage. Secondary measures recorded mood states, sleep quality, and overall quality of life. Results suggested that combined Ginkgo/Panax supplementation significantly improved memory (by an estimated 7.5%).
Researchers believed that these memory improvements occurred with all types of memory including: working and long-term memory. Memory enhancement was noted throughout the 12 weeks of supplementation and through Week 14 (the 2 week washout phase). This was among the first studies to note memory improvements among middle-aged volunteers as a result of an herbal compound (Ginkgo/Panax).
- Source: http://www.ncbi.nlm.nih.gov/pubmed/11140327
2004: In effort to expand upon previous research suggesting efficacy of Ginkgo and Ginseng for memory enhancement, researchers conducted a long-term analysis of the compound on a larger-scale sample. For the study, participants were recruited from a database containing 3500 adults between 35 and 80 years old. Measures for the study included 8 memory tests: 5 measured “episodic memory,” while the remaining 3 measured “semantic memory.”
Among the 3500 participating adults, only 40 (1.1%) reported that they had been using Ginkgo Biloba regularly over a long-term. Among the 40 that had been using Ginkgo, only 19 had used it for 2+ years, with the other 21 individuals having taken it for just over 5 months (on average). A total of 86 individuals (2.5%) reported that they had been using Ginseng regularly; 51 of these individuals had used for 2+ years, while the other 35 had used for just over 5 months (on average).
Results revealed no significant differences between the control groups and the individuals taking Ginkgo Biloba or Ginseng. In fact, the individuals not taking Ginkgo actually performed significantly better at some tasks (e.g. cued verbal recall). This further elucidates the fact that neither Ginkgo Biloba nor Ginseng improve memory or learning, even when taken over a long-term.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/14647971
2011: A specific Ginkgo Biloba extract classified as “EGb 761” has been noted as an effective performance enhancer among individuals with cognitive deficits. In 2011, a study analyzed the efficacy of the EGb 761 extract for improving memory in middle-aged volunteers. For the study, a total of 188 participants (ages 45 to 56) randomly received EGb 761 at 240 mg or a placebo for a 6 week term.
Assessments were administered to document memory performance, utilizing a “free recall test” (appointment list) and “recognition test” (driving route). Following 6 weeks, it was noted that those taking the EGb 761 significantly improved in their “free recall test,” correctly remembering more appointments. This suggests that EGb 761 (240 mg) can improve cognitively demanding memory tasks (e.g. free recall).
- Source: http://www.ncbi.nlm.nih.gov/pubmed/21802920
2012: A randomized, controlled, multicenter trial was conducted to determine whether Ginkgo Biloba acts as a neuroprotective agent against neurodegenerative diseases. It has been hypothesized that Ginkgo Biloba could decrease brain cell death, lower inflammation, and act as an antioxidant to maintain brain health. Researchers specifically investigated whether Ginkgo could improve cognitive function among those diagnosed with mild cognitive impairment (MCI).
The study incorporated 120 participants all of whom were diagnosed with mild cognitive impairment and between 60 and 85 years of age. Of the 120 participants, 60 were assigned to receive Ginkgo tablets 3 times per day at 19.2 mg, while the remaining 60 were assigned to receive a placebo. The tests to determine change in cognitive function included a picture recognition test and a logical memory test.
Following 6 months of treatment, individuals receiving Ginkgo Biloba experienced significant improvements on both the picture recognition and logical memory tests compared to the control. It was noted that the Ginkgo group recognized pictures at a rate of 55.17%, whereas the control group only recognized them at a rate of 32.73%. Authors concluded that Ginkgo tablets demonstrate efficacy for episodic memory enhancement among individuals with mild cognitive impairment.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/22704410
Mood improvement: One study from 2002 suggested that Ginkgo Biloba may simultaneously improve mood and cognitive function. This study incorporated a total of 20 participants that were set to receive either Ginkgo Biloba (360 mg), Ginseng (400 mg), a combination Ginkgo/Ginseng (960 mg), or a placebo. While both the Ginkgo, Ginseng, and combination of Ginkgo/Ginseng was noted as improving cognitive function – only the Ginkgo was reported to improve mood.
Mood was recorded prior to testing and measured with Bond-Lader visual analogue scales. These scales allow researchers to understand subjective changes in mood that may occur upon supplementation. The Ginkgo Biloba (360 mg) was reported to improve self-rated mood following administration, with a subtler mood improvement noted from the combination Ginkgo/Ginseng (960 mg).
This study suggests that Ginkgo (360 mg) could improve mood in certain individuals. It is important to keep in mind that this is a very small-scale study, therefore this finding may be debunked in a larger-scale trial with a greater number of participants.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/12020739
Neurodegenerative diseases: Ginkgo has long been investigated as a therapeutic intervention for the treatment and/or prevention of neurodegenerative diseases like dementia. Many trials have been conducted to determine whether standardized Ginkgo Biloba extract (EGb 761) could be therapeutically useful among individuals with neurodegeneration. Some research has found Ginkgo to be equally effective as a pharmaceutical cholinesterase inhibitor at treating symptoms of dementia.
Studies investigating Ginkgo as a potentially preventative agent have reported no decrease in risk of neurodegenerative diseases is associated with long-term supplementation. Despite the fact that it doesn’t decrease risk, there is some evidence that EGb 761 improves symptomatic severity and individual functionality.
1998: A meta-analysis was published in 1998 analyzing all studies in which Ginkgo was administered to individuals with cognitive impairment and/or dementia. All studies incorporated within this meta-analysis included individuals diagnosed with a neurodegenerative disease and administered Ginkgo extract. Moreover, all trials within this analysis were double-blind, placebo-controlled, and randomized – plus incorporated at least one assessment of cognitive function.
While over 50 studies were identified, just 4 were considered comprehensive enough to meet inclusion criteria. Within the 4 studies included, there were a total of 212 participants. Authors of this meta-analysis concluded that Ginkgo Biloba administration of 120 mg/day to 240 mg/day over a 3 to 6 month period can significantly improve cognitive function among those with Alzheimer’s disease.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/9823823
2006: A study was published in 2006 investigating the effect of the “EGb 761” extract (derived from Ginkgo Biloba) among individuals with Alzheimer’s disease. Researchers specifically wanted to compare its effect to cholinesterase inhibitors (or drugs that inhibit the enzymatic breakdown of the neurotransmitter acetylcholine) and determine whether it could slow disease progression. The design was considered placebo-controlled and double-blinded, and took place over a period of 24 weeks.
All individuals participating in the study were suffering from dementia (mild or moderate) and were assigned to receive one of the following: EGb 761 (160 mg), the drug Donepezil (5 mg), or a placebo. Dementia severity was assessed with the Syndrom Kurz test and Mini-Mental State Examination. Results noted that Ginkgo Biloba (EGb 761 extract) was equally as effective as Donepezil at reducing symptoms of dementia.
The authors note that there appear to be no significant differences between EGb 761 and Donepezil for the treatment of mild to moderate Alzheimer’s disease. This is some of the first research to compare an herbal compound directly to an established drug for the treatment of a neurodegenerative disease. Some individuals may prefer EGb 761 due to the fact that it is associated with few side effects.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/16930364
2008: Another study was published in 2008 documenting the effect of Ginkgo Biloba compared to a placebo for the treatment of dementia and Alzheimer’s disease among an elderly population. All participants in this study were at least 75 years of age and classified as having normative cognition (2587 individuals) or mild cognitive impairment (482 individuals). The study was considered double-blind, randomized, and placebo-controlled and took place from 2000 to 2008.
The participants were assigned to receive either Ginkgo Biloba (120 mg) twice daily or a placebo; 1545 individuals received the Ginkgo and 1524 individuals received the placebo. Every 6 months, participants were assessed for symptoms of dementia. Authors effectively concluded that Ginkgo Biloba was not effective for the prevention of dementia and Alzheimer’s disease among elderly individuals – regardless of whether they had normative cognition or mild cognitive impairment.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/19017911
2009: In 2009, a review of evidence documented the efficacy of Ginkgo Biloba for the treatment of dementia or cognitive decline. It was hypothesized that the mechanism of action involving: dilation of blood vessels, decreasing viscosity, altering neurotransmission, and decreasing free radicals – could decrease likelihood of cognitive decline. This review incorporated studies that were considered double-blind, randomized, and placebo-controlled.
Researchers extracted 36 trials that fit their criteria – most were noted as being small-scale and of short-term. A majority of trials compared Ginkgo Biloba or EGb 761 at either low or high doses. Authors concluded that among individuals with dementia and/or impaired cognitive function, the benefit associated with Ginkgo Biloba should be considered inconsistent and unreliable.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/19160216
2010: A review of evidence was published in 2010 discussing Ginkgo Biloba as a potential treatment for Alzheimer’s disease. Researchers compiled data from randomized controlled trials among individuals with Alzheimer’s disease. All of the trials needed to incorporate the usage of Ginkgo Biloba and compare it to a placebo and/or other established pharmaceutical.
A total of 6 studies met criteria to be incorporated in this review, all of which suggested therapeutic efficacy associated with Ginkgo Biloba supplementation. Improvements were noted among individuals via measures of: daily living and psychopathological symptoms. Due to the fact that no significant adverse reactions are apparent, this review suggests benefit from Ginkgo among those with Alzheimer’s disease.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/21170694
2012: Researchers sought to determine whether administration of Ginkgo Biloba could prevent Alzheimer’s disease among elderly adults with memory deficits. They set up a double-blind, randomized, placebo-controlled clinical trial with 70 adult participants. All participants had reported memory deficits to a primary-care medical doctor.
Of these participants, some were assigned to receive 120 mg Ginkgo Biloba extract (EGb 761) twice per day, while others received a placebo. Researchers followed participants over the course of 5 years to determine whether Ginkgo may prevent Alzheimer’s disease. Results indicated that long-term administration of Ginkgo Biloba extract did not decrease Alzheimer’s risk compared to a placebo.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/22959217
2015: A meta-analysis was conducted in 2015 to elucidate the therapeutic benefits and adverse reactions associated with Ginkgo Biloba extract (EGb 761) for the treatment of cognitive impairment and dementia. Researchers noted that 9 trials met inclusion criteria for the analysis – all of which spanned between 22 to 26 weeks in duration and incorporated 2,561 participants. Cognitive improvement was considered significant among participants receiving EGb 761 compared to a placebo.
In addition, significant improvements in measures of daily living activity were reported for individuals taking EGb 761. The Clinicians’ Global Impression of Change (CGIC) scale also recorded significant improvements among those taking EGb 761 compared to the placebo. Reported benefits were associated with dosages of 240 mg per day.
Researchers concluded that EGb 761 at 240 mg per day is capable of slowing cognitive decline, behavioral, and functional impairments among those with impaired cognition and/or dementia. Therapeutic efficacy was most pronounced among individuals with psychiatric symptoms.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/25114079
2015: A meta-analysis investigated the efficacy of Ginkgo Biloba for the prevention of dementia among those without dementia. Researchers included studies that were placebo-controlled, randomized, and double-blind – all of which compared Ginkgo’s effect to that of a placebo. This meta-analysis incorporated a total of 2 trials with a total of 5,889 participants.
Results indicated that there was no significant difference in dementia diagnoses among those taking Ginkgo Biloba compared to a placebo. While both reports indicated that Ginkgo was safe with no significant adverse reactions, there is no clear evidence to recommend Ginkgo Biloba supplementation for the prevention of dementia. Therefore, there’s no need to seriously consider it as a potential preventative agent.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/26058281
Sexual dysfunction: Some believe that Ginkgo Biloba may be effective for the treatment of sexual dysfunction, particularly cases induced by SSRI antidepressants. Results from an open-label trial published in 1998 suggested that Ginkgo Biloba supplementation could counteract SSRI-induced sexual dysfunction. In the mentioned open-label trial, a total of 63 participants (33 females and 30 males) received 60 mg/day to over 200 mg/day of Ginkgo.
This trial discovered that Ginkgo supplementation was over 80% effective in mitigating SSRI-induced sexual dysfunction. Evidence revealed that females experienced a greater benefit from Ginkgo (over 90%) than males (over 75%). Authors noted that Ginkgo supplementation improved all major aspects of sexuality including: desire, excitability, orgasm, and resolution.
The concept for the study emerged when a professional noted that a geriatric patient taking Ginkgo noticed improved erections. It is thought that Ginkgo supplementation could help offset sexual dysfunction caused by any antidepressants including: SNRIs, TCAs, and MAOIs. Possible mechanisms of sexual enhancement include: modulation of neurotransmitters and peripheral vasodilation.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/9611693
Skin health: A claim associated with Ginkgo Biloba is that supplementation can improve skin health. Many cosmetic formulas incorporate natural herbal extracts, one of which may be Ginkgo Biloba. A study published in 2014 sought to determine whether administration of a formulation containing Green Tea and Ginkgo Biloba could improve skin health.
In a preclinical study, a skin analysis was conducted on hairless mice and the formulation was applied to the dorsum region. In the clinical study, the herbal formulation was administered to the forearm region of 48 volunteers and assessments were conducted 3 hours post-administration as well as after 15 days of administration and then again after 30 days of administration. In the mice, the blend of Green Tea and Ginkgo increased the thickness of the skin and elicited a moisturizing effect.
The human clinical studies demonstrated that the herbal formulation also had a moisturizing effect and simultaneously improved skin elasticity. It is believed that the combination of the Green Tea and Ginkgo Biloba elicit synergistic effects to improve skin health. The effect on increasing skin elasticity was clinically significant in both the preclinical and clinical research.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/25226010
Stroke rehabilitation: Individuals that experience a stroke have a high risk of mortality and developing severe neurological impairments. In effort to help individuals recover from a stroke, various training exercises, pharmaceuticals, and supplements are administered. In 2013, researchers investigated the potential of Ginkgo Biloba to improve neural rehabilitation among individuals that experienced a stroke.
The study conducted was double-blind, placebo-controlled, and fully randomized. Stroke symptom severity was measured with the NIH (National Institute of Health) Stroke Scale. The study included 102 participants that had experienced an acute ischemic stroke, some of which received Ginkgo Biloba (52), and others received placebo tablets (50) for 4 months.
Following 4 months of receiving either Ginkgo or a placebo, the participants were re-assessed with the NIH Stroke Scale. Results suggested that individuals receiving Ginkgo Biloba experienced greater recovery compared to those receiving a placebo. It was noted that 17 individuals from the Ginkgo group experienced 50% reductions on Stroke Scale scores compared to baseline, while only 5 individuals from the placebo group experienced 50% reductions.
Despite the fact that the specific mechanisms by which Ginkgo enhances stroke rehabilitation, this study provides evidence to justify its use as a supplement post-stroke. While further research is needed and larger trials are necessary to confirm this finding, it appears as Ginkgo may have some therapeutic benefit for stroke rehabilitation.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/23871729
2014: A meta-analysis published in 2014 analyzed the effect of Ginkgo Biloba Extract (GBE) among animals that had suffered from a cerebral ischemic stroke. Researchers searched scientific databases for all studies with administration of Ginkgo among animals that had suffered a stroke. Studies incorporated within the meta-analysis spanned from 1980 to 2013 and a total of 42 publications met inclusion criteria.
Results from this meta-analysis suggested that administration of Ginkgo Biloba improved stroke rehabilitation by nearly 34% compared to a control. Several factors including the: animal species, methods, measures (and timing), route of administration, and dosage of Ginkgo all influenced the outcome. Authors suspect that Ginkgo may offer neuroprotective benefits, reducing inflammation, scavenging free radicals, and decreasing likelihood of neuron death.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/25004874
Tinnitus: Millions of people experience tinnitus, a condition classified as the incessant perception of ringing and/or buzzing in the ears. Some have suggested that supplementation of Ginkgo Biloba may improve tinnitus, ultimately reducing and/or mitigating the ringing. Despite preliminary evidence suggesting efficacy of Ginkgo for tinnitus, many of these studies haven’t ruled out a possible placebo effect.
A review of evidence published in 2013 analyzed all studies determining the effect of Ginkgo on adults (over 18 years old) with tinnitus stemming from cerebral insufficiency. A total of 4 studies with a total of 1,543 participants met inclusion criteria for the review. Among these trials, there was no significant evidence to claim that Ginkgo supplementation reduced tinnitus.
It should be noted that there was a small decrease in tinnitus (based on a symptom scale) among individuals with dementia and Alzheimer’s disease. That said, there is insufficient evidence to conclude that Ginkgo is a helpful supplement for individuals with tinnitus.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/23543524
Vertebrobasilar insufficiency: Researchers have investigated Ginkgo Biloba for the treatment of symptoms stemming from vertebrobasilar insufficiency (VBI). Vertebrobasilar insufficiency is a condition characterized by lack of blood flow to posterior regions of the brain, resulting in dizziness and headaches. A study conducted in 2015 analyzed the effect of Ginkgo Biloba among 60 participants diagnosed with VBI.
Of the 60 participants, 30 were administered “persimmon leaf extract” and the remaining 30 were administered Ginkgo Biloba extract. Symptomatic severity was evaluated after 30 days of treatment, particularly headaches and dizziness. Results indicated that “persimmon leaf extract” significantly improved measures of VBI (~88%) compared to Ginkgo Biloba (~73%), but both seem to offer benefit.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/25864752
Visual perception: Another myth associated with Ginkgo Biloba supplementation is that it can improve eyesight and aspects of visual perception. Some claims suggest that supplementation may improve age-related macular degeneration and/or glaucoma-induced contrast sensitivity. Recent research is unclear in determining efficacy of Ginkgo for visual enhancement among those with deficits; future research may discover benefits.
2013: Due to the fact that Ginkgo Biloba is known to ramp up blood flow to the brain and scavenge free radicals, some researchers suspected that it may slow the development of age-related macular degeneration (AMD). The researchers hypothesized that Ginkgo may be able to alter vascular functioning and reduce oxidative stress, thus slowing the onset and severity of macular degeneration stemming from age.
They conducted a review of evidence, considering certain studies up to 2012. The trials selected were all randomized and involved Ginkgo Biloba Extract administration among individuals with age-related macular degeneration. Researchers were able to find 2 trials that met inclusion criteria, with a total of 119 participants.
Of the 2 studies incorporated within this research, the treatment period with Ginkgo was approximately 6 months. Both studies suggested benefit associated with Ginkgo supplementation for the treatment of age-related macular degeneration. Although both studies suggest benefit, Ginkgo cannot be clinically recommended until more convincing evidence is compiled.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/23440785
2014: It has long been hypothesized that Ginkgo Biloba extract could improve visual function among individuals with tension glaucoma. A study published in 2014 utilized a placebo-controlled, randomized design to determine whether administration of Ginkgo Biloba could improve visual field defect and contrast sensitivity among those with glaucoma. The study consisted of 35 individuals that underwent 8 weeks of treatment.
A total of 18 participants received Ginkgo Biloba (40 mg) thrice per day for 4 weeks followed by a placebo for 4 weeks. The remaining 17 participants received a placebo for 4 weeks followed by the Ginkgo for 4 weeks. Primary measures were recorded based on 24-2 SITA standard visual field testing and secondary measures were derived from IOP and self-reports.
This study found no significant difference between placebo and Ginkgo administration for the enhancement of visual function among those with tension glaucoma. This contradicts previous findings suggesting therapeutic efficacy of Ginkgo for treating visual impairment among glaucoma patients. Contrast sensitivity and mean defect remained the same throughout the trial.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/24282229
Are there any major benefits associated with Ginkgo Biloba supplementation?
While the benefits associated with Ginkgo Biloba and various extracts (i.e. EGb 761) may be overstated by supplement companies, there remains limited evidence to suggest therapeutic efficacy of Ginkgo for a variety of conditions. Unfortunately many of the studies with positive findings are small-scale and/or poorly designed. In addition, many of them highlight the potential of Ginkgo Biloba as a therapeutic agent for a certain condition, but conclude that evidence remains unclear and/or insufficient to make clinical recommendations.
For example, the aforementioned research highlights potential benefit associated with Ginkgo Biloba in the realms of: ADHD, Alzheimer’s disease, cognitive function, dementia, mood, sexual enhancement, skin health, stroke rehabilitation, and working memory. In addition, many of these benefits have been noted to occur after a mere single-dose, and others have been sustained over a longer-term (e.g. weeks). Despite all of the possible benefits associated with Ginkgo Biloba, there are many conditions for which it is ineffective or unlikely to be effective.
Conditions for which Ginkgo Biloba is unlikely to be clinically effective include: hypertension and vertebrobasilar insufficiency. Studies demonstrate that Ginkgo Biloba was ineffective for reducing risk of neurodegenerative diseases, preventing neurodegenerative diseases, enhancing learning abilities, treating glaucoma, and mitigating tinnitus.
Limitations of Ginkgo Biloba Research
Despite findings that Ginkgo Biloba may be beneficial for certain aspects of mental and physical health, it is unknown as to whether many of these findings are legitimate. There are many limitations associated with Ginkgo Biloba research, perhaps most obvious is the fact that most studies are: small-scale (with limited participants), vary in the type of Ginkgo administered, and often fail to implement robust designs.
- Contradictory findings: A major limitation with Ginkgo Biloba research is that many studies contradict each other with findings. For example, some studies have shown clear benefit associated with taking Ginkgo for the enhancement of memory, while others suggest no apparent benefit. With contradictory findings, it is necessary for future research to incorporate more robust designs with a larger number of participants.
- Evaluation criteria: Many studies utilized different evaluation criteria compared to others. Despite the fact that 2 studies may seek to determine the effect of Ginkgo on cognitive function, the measures used to evaluate cognition differ between the studies. It is important to clarify the specific evaluations and use common criteria so that future research can expand upon past-findings.
- Dosage variation: Not all studies incorporate the same dosage of Ginkgo Biloba. Some studies may administer a small amount, while others may utilize large doses. It would be helpful if researchers explain the rationale behind dosing protocols and for future research to use similar protocols assuming they are logically sound.
- Participants: It is important to consider the number of participants involved in Ginkgo trials as well as the diversity of participants. Many studies analyze a small number of participants and the study population lacks adequate diversity. It is important to incorporate a diverse sample (e.g. different ages, sexes, ethnicities) to understand Ginkgo’s effect on a large-scale.
- Short-term trials: Many trials of Ginkgo are extremely short-term, some are only “single-dose” studies. The goal should be to ramp up the length of many of these studies to determine outcomes of Ginkgo treatment after longer durations such as 6 months or 1 year. This would help us better understand long-term effects of supplementation and help determine if therapeutic benefits are maintained, increase, or decrease over a longer term.
- Small-scale studies: Many studies are extremely small-scale and need to be larger in terms of sample size. Small-scale trials may show a positive effect from Ginkgo supplementation, but a larger sample may debunk the finding of the smaller trial. In small-scale trials, it is generally easier to attain a fluke “positive” outcome than in a larger-scale trial.
- Study designs: To better understand the efficacy of Ginkgo for treating certain conditions, study designs should be significantly improved. All studies should incorporate a double-blind, placebo-controlled, randomized design. Should a study be missing a component of “blinding,” a placebo, or randomization – results may be wrongfully skewed.
- Types of Ginkgo used: One element that many researchers fail to consider is the specific type of Ginkgo being utilized. Some strains are clearly higher quality than others, and the contents of various phytochemicals and bioactive compounds should be considered. While many studies use “standard Ginkgo Biloba,” others specifically use the EGb 761 compound. Researchers will need to do a better job of clarifying the specific origin and type of Ginkgo they’re using to account for differences that could alter study outcomes.
Further Research of Ginkgo Biloba is Warranted
Ginkgo Biloba has demonstrated significant promise for the treatment and/or improvement of many psychological conditions. Due to the fact that most hypothesized therapeutic benefits remain inconclusive and/or unclear, further research is warranted. It is necessary to first get a better understanding of the mechanisms by which Ginkgo Biloba elicits certain effects.
It may then be helpful to determine potential differences in mechanisms of action between various strains of Ginkgo Biloba. In addition, further research would help us understand whether Ginkgo Biloba can be used for therapeutic benefit by certain individuals or whether usage of this herb could be a waste of money and/or result in adverse effects. Larger scale trials will help debunk any false claims associated with Ginkgo, while simultaneously elucidating any notable benfeits.
At this time, we lack the understanding of whether Ginkgo supplementation offers any significant benefit. It appears that the most effective strain is EGb 761 – most studies incorporating this Ginkgo Biloba Extract demonstrate benefit. It would also be helpful to know whether supplementation offers a nootropic effect among healthy individuals rather than solely among those with forms of cognitive impairment.
Have you noticed any Ginkgo Biloba benefits?
If you’ve used Ginkgo Biloba, feel free to share whether you noticed any benefits in the comments section below. Would you consider the benefits you experienced to be significant and noticeable or subtle and difficult to notice? To help others get a better understanding of your situation, be sure to mention the type (strain) of Ginkgo (e.g. EGb 761) you were taking, your daily dosage, and how long you took it.
Were you taking the Ginkgo Biloba for a specific reason such as to enhance memory or improve cognition? If you are certain that Ginkgo was therapeutically beneficial, how were you able to rule out the placebo effect? Also consider the fact that unless you take Ginkgo as a standalone supplement (without other drugs or supplements), it may be difficult to interpret its specific effects.
Understand that certain individuals may be more likely to reap therapeutic benefits (e.g. cognitive enhancement) compared to others. This may be due to complex individual differences such as genetics, neurophysiology, time of day Ginkgo was supplemented, the dosage, and/or interactions from other substances. In addition, the brand of Ginkgo Biloba (quality, strain, additives, etc.) may influence subjectively reported benefits.