Wiklund 1994

Randomized, double‐blind, placebo controlled study to assess the effects of a combination of active substances including ginseng extract Gl15 on quality of life (QOL) in healthy, employed volunteers older than 25 years.

Results: After 12 weeks of treatment, both the combination and placebo groups improved their general well being, but the improvement from baseline was more pronounced in those participants taking the combination of active substances (Gericomplex soft gelatin capsules containing 40 mg ginseng extract Gl15 and vitamins, minerals, and trace elements) twice daily.

Conclusions: In healthy participants the combination of vital substances including Gl15 offered significant advantages over placebo treatment in terms of improvement in self‐assessed feelings of vitality, alertness, less time urgency (that is, feeling more relaxed), and appetite. The beneficial effects appeared to be more pronounced in those participants who were at a disadvantage and worse off before the study started.

Reasons for exclusion: Cognitive function was not tested.

Neri 1995

Randomized, double‐blind, placebo controlled study to compares psychological well‐being and perceived quality of life in participants with age‐associated memory impairment (AAMI), who were administered Gegorvit® (Pharmaton S.A., Switzerland) or placebo for 9 months.

Results: Drug‐treated AAMI subjects differ from controls in part by improved scores on objective cognitive tests but even more so by modifications of the correlations among indexes of psychological well‐being and quality of life.

Conclusions: Ginseng might act on some of the mechanisms underlying AAMI and met the prerequisites as a candidate for drug therapy.

Reasons for exclusion: Number (or %) of follow‐up from each group was not stated. Therefore, relevant data could not be extracted.

Sotaniemi 1995

Randomized, double‐blind, placebo controlled study to investigate the effect of ginseng on newly diagnosed non‐insulin dependent diabetes mellitus (NIDDM) participants.

Results: Ginseng 100 mg or 200 mg (Dansk Droge, Copenhagen) daily for 8 weeks elevated mood, improved mood, vigor, well‐being, and psychomotor performance, but not memory, and reduced fasting blood glucose (FBG) and body weight. The 200 mg dose of ginseng improved glycated hemoglobin, serum aminoterminalpropeptide (PIIINP), and physical activity. The participants completed the study without any side effects.

Conclusions: Ginseng might be a useful therapeutic adjunct in the management of NIDDM.

Reasons for exclusion: Neither baseline results nor change from baseline values could be extracted.

Thommessen 1996

A double‐blind, placebo controlled study to examine the effect of ginseng (Gericomplex, Pharmaton S.A., Switzerland) as an adjuvant to treatment and rehabilitation of geriatric participants.

Results: After treated with two capsules of ginseng or placebo for 8 weeks, length of stay in hospital did not differ in the two groups. Both groups also improved to the same degree on the various functional outcome measures, except for the Kendrick Object Learning test, where the placebo group improved more markedly.

Conclusions: No identifiable effects of ginseng as an adjuvant to treatment and rehabilitation of geriatric participants were observed.

Reasons for exclusion: A clinical controlled study. "Randomization" was never mentioned in the paper. No additional information of sequence generation could be obtained from the first author.

Kennedy 2001

Randomized, double‐blind, placebo‐controlled, Latin square cross‐over study to observe whether acute administration of Panax ginseng extract (G115®, Pharmaton SA) might have effects on mood and cognitive performance.

Results: "Quality of Memory" and the associated "Secondary Memory" factor at all time points following 400mg of ginseng improved significantly. Both the 200 and 600mg doses were associated with a significant decrement of the "Speed of Attention" factor at later testing times only. Subjective ratings of alertness were also reduced 6h following the two lowest doses.

Conclusions: Single doses of ginseng were capable of a dose dependent modulation of cognitive performance in healthy young adults.

Reasons for exclusion: Data could not be extracted from the complicated Latin square cross‐over study.

We contacted Professor David Kennedy on 27 May 2009 for additional information.

Ellis 2002

Randomized, double‐blind, placebo controlled study to assess the time‐dependent effects of Panax ginseng on health‐related quality of life (HRQOL) in healthy young volunteers.

Results: After 4 weeks of therapy, higher scores in social functioning, mental health, and the mental component summary scales were observed in participants randomized to Panax ginseng (Ginsana), these differences did not persist to the 8‐week time point. The incidence of adverse effects was 33% in the Panax ginseng group compared with 17% in the placebo group. Participants given Panax ginseng (58%) were more likely to state that they received active therapy than participants given placebo.

Conclusions: Panax ginseng (Ginsana) improves aspects of mental health and social functioning after 4 weeks of therapy, although these differences attenuate with continued use.

Reason for exclusion: Cognitive function was not tested.

Tian 2003a

Randomized, single‐blind, placebo controlled study to evaluate the effect of King's Brain pill (Compound Chinese ginseng extract from herbs) on the treatment and the delaying of memory decline in the elderly with mild cognitive impairment (MCI) in a community by a year follow‐up of neuropsychology.

Results: Mean MMSE score increased after treated with 4 pills of King's Brain pill (1.5 g) thrice a day for 3 months, while decreased at one year follow‐up point, but still higher than that in placebo group (P<0.05). Verbal Learning Test score was significantly increased at follow‐up point in the King's Brain pill group , which was significantly higher than that in the placebo group (P<0.01). The total score of memory items on BNPT battery (Bristol Memory Disorders Clinic‐Revised) was significantly increased at follow‐up point in the King's Brain pill group, higher than that in Piracetam group (P<0.05) and the placebo group ( P<0.01) .

Conclusions: King's Brain spill had protective effect on cognitive and memory decline in elderly with MCI.

Reasons for exclusion: King's Brain pill was a compound containing ginseng as a major component. Sales manager from Henan Wanxi Pharmaceutical Company said that King's Brain pill (Jin Si Wei) was not a compound on the market. Clinical information of King's Brain pill besides this study could not be found from academic database and the company.

Tian 2003b

This was a poster presentation at the American Stroke Association's 28th International Stroke Conference.

A randomized, double‐blind, pilot study to evaluate the effectiveness of a compound of Chinese ginseng tablet (King's Brain pill) in the treatment of memory impairment in participants with dementia after stroke.

Results: After given one tablet of ginseng compound thrice a day for 12 weeks, a significant increase in mean scores on the HVLT and increase in total memory scores have been observed. There were greater improvements in episodic memeory function assessing story recall, delayed word recall, verbal learning and verbal recognition and visual recognition in the compound Chinese ginseng group than in the duxil‐controlled group.

Conclusions: Treatment with the compound of Chinese ginseng extract might improve memory function in participants with mild and moderate dementia after stroke and might warrant further research treatment strategies for VaD.

Reasons for exclusion: King's Brain pill was a compound containing ginseng as a major component. Not placebo controlled trial, since the comparison was Duxil.

Tian 2003

This was an abstract for the Asia Pacific scientific forum new discoveries in cardiovascular disease and stroke: Bench to bedside to community. It was the same as the abstract of Tian 2003a.

Kennedy 2004

Randomized, double‐blind, counterbalanced, placebo‐controlled study not only provided an examination of the cognitive and mood effects of guarana in healthy young volunteers, but also assessed the potential for additive or synergistic effects following the common, commercially available, combination of guarana with Panax ginseng.

Results: In comparison to placebo, 75 mg of a dried ethanolic extract of guarana (approx 12% caffeine), 200 mg of Panax ginseng extract (G115®, Pharmaton SA), and their combination (75 mg/200 mg) resulted in improved task performance throughout the day. In the case of guarana, improvements were seen across 'attention' tasks (but with some evidence of reduced accuracy), and on a sentence verification task. While also increasing the speed of attention task performance, both ginseng and the ginseng/guarana combination also enhanced the speed of memory task performance, with little evidence of modulated accuracy. Guarana and the combination, and to a lesser extent ginseng, also led to significant improvements in serial subtraction task performance.

Conclusions: These results provided the first demonstration in humans of the psychoactive effects of guarana, and confirmation of the psychoactive properties of ginseng.

Reasons for exclusion: The Latin‐square design cross‐over trial compared other types of intervention besides ginseng was excluded since it was very difficult to evaluate the 'carry‐over' effect due to other intervention. Data could not be extracted from the complicated Latin square cross‐over study.

Reay 2005

Randomized, double‐blind, placebo‐controlled, Latin square cross‐over study to investigate the effects of two separate single doses (200 mg and 400 mg) of Panax ginseng extract (G115®, Pharmaton SA) on changes in fasted blood glucose levels and performance during sustained mentally demanding tasks.

Results: 200 mg ginseng could significantly improved Serial Sevens subtraction task performance and significantly reduced subjective mental fatigue throughout all (with the exception of one time point in each case) of the post‐dose completions of the 10min battery.

Conclusions: Panax ginseng could improve performance and subjective feelings of mental fatigue during sustained mental activity.

Reasons for exclusion: Data could not be extracted from the complicated Latin square cross‐over study.

We contacted Professor David Kennedy on 27 May 2009 and Dr Jonathon Reay on 8 July 2009 for additional information.

Reay 2006

Randomized, double‐blind, counterbalanced, placebo‐controlled study to investigate the effects of single doses of Panax ginseng, glucose, and a combination of Panax ginseng and glucose on blood glucose levels and cognitive performance during sustained 'mentally demanding' tasks.

Results: Both Panax ginseng and glucose enhanced performance of a mental arithmetic task and ameliorated the increase in subjective feelings of mental fatigue experienced by participants during the later stages of the sustained, cognitively demanding task performance. Accuracy of performing the Rapid Visual Information Processing task (RVIP) was also improved following the glucose load. There was no evidence of a synergistic relationship between Panax ginseng and exogenous glucose ingestion on any cognitive outcome measure. Panax ginseng caused a reduction in blood glucose levels 1 hour following consumption when ingested without glucose.

Conclusions: These results confirmed that Panax ginseng might possess glucoregulatory properties and could enhance cognitive performance.

Reasons for exclusion: The Latin‐square design cross‐over trial compared other types of intervention besides ginseng was excluded since it was very difficult to evaluate the 'carry‐over' effect due to other intervention. Data could not be extracted from the complicated Latin square cross‐over study.

Reay 2008

Randomized, double‐blind, placebo controlled, two‐period cross‐over study to assess the behavioural and mood effects of chronic ingestion of Panax ginseng (G115).

Results: Results revealed improvements in working memory following a single acute dose of Panax ginseng have been observed, whereas, following chronic dosing results revealed both improvements and decrements in aspects of cognition and mood.

Conclusions: An observed effect on a performance measure following chronic ingestion can be further modulated by that day's acute dose.

Reasons of exclusion: Only the abstract has been published and data were not obtainable from the author.

Heo 2008

Randomized, open‐label pilot study to evaluate the adjunctive effect of Korean red ginseng (KRG) in AD.

Results: Participants in the high‐dose (9 g/day) KRG group showed significant improvement on the ADAS and CDR after 12 weeks of KRG therapy when compared with those in the control group. Both low‐dose (4.5 g/day) and high‐dose (9 g/day) KRG groups showed improvement from baseline MMSE when compared with the control group, but this improvement was not statistically significant. Two participants in the low‐dose KRG group complained of feeling feverish and two participants in the high‐dose KRS group complained of nausea.

Conclusions: KRG showed good efficacy for the treatment of AD; however, further studies with larger samples of participants and a longer efficacy trial should be conducted to confirm the efficacy of KRG.

Reasons for exclusion: This was not a blinded study. The trial compared KRG as an adjuvant therapy to conventional anti‐dementia medications, not placebo controlled trial.

Lee 2008

Randomized, open‐label prospective study to evaluate clinical efficacy of Panax ginseng in the cognitive performance of AD participants.

Results: After 12 weeks of the Panax ginseng powder (4.5 g/d) treatment, the cognitive subscale of ADAS and the MMSE score began to show improvements and continued up to 12 weeks. At 12 weeks after the ginseng discontinuation, the improved ADAS and MMSE scores declined to the levels of the control group. The adverse events (e.g. heat‐sense, dizziness, nausea, anorexia, diarrhea and headache) were mild and transient.

Conclusions: Panax ginseng was clinically effective in the cognitive performance of AD participants.

Reasons for exclusion: This was an open‐label trial with no blinding performed. Both Ginseng group and control group continued the conventional therapy, not placebo controlled trial.