Ginkgo and Korean ginseng combined boost brainpower – Phytotherapy Review & Commentary – Brief Article
Kerry Bone
While on the topic of boosting brainpower, a study described in press releases as a “landmark clinical trial” found that a combination of Korean ginseng (Panax ginseng) and Ginkgo’ (Ginkgo biloba) can significantly enhance mental performance in healthy, middle-aged people. The 14-week, double-blind, placebo-controlled randomized trial studied the cognitive effects of the herbal combination in 256 healthy volunteers between the ages of 38 and 66 years. Trial participants performed a battery of tests using the Computerized Cognitive Assessment system. Volunteers receiving the ginseng and Ginkgo demonstrated statistically significant improvements in cognitive function compared to the placebo group. (1)
Another study by scientists at the University of Northumbria (England) examined the acute effects of Korean ginseng and Ginkgo on mental performance in healthy volunteers. (2) College students were tested four times between one and six hours after taking the herbs. Those receiving Ginkgo only demonstrated significantly improved concentration within 2.5 hours. The highest dose tested (360 mg of 50:1 standardized extract) was the most effective. A dose of 400 mg of 5:1 Korean ginseng extract (equivalent to 2 g of root) sharpened memory after just one hour, with improvements in ability to store, hold and retrieve information.
But when both the Ginkgo extract (360 mg equivalent to 18 g of leaf) and the Korean ginseng extract (600 mg, equivalent to 3 g of root) were combined as a single treatment, the results were remarkable. Not only was the effect on cognitive function more pronounced than treatment with either herb on its own, it was immediately evident when the volunteers were first tested. The lead researcher, Dr Andrew Scholey was quoted as saying: “The results were incredible in terms of improvements in speed and accuracy — usually there is a trade-off and you improve one at the expense of the other.”
The research team from the University of Northumbria also compared the effects of glucose, oxygen and Ginkgo on the mental acuity of college students in separate studies. In one test, students received 25 grams of glucose or a placebo (which was obviously not the usual sugar placebo) and were then asked to perform arithmetic calculations. (3) The students who received the glucose could perform more calculations in a 2-minute period than those who took the placebo. In the experiment involving oxygen, the researchers required the students to memorize 15 words after breathing oxygen or just air. Those receiving the oxygen were able to remember two to three more words than the placebo group. (4)
But the striking finding was while the glucose and oxygen boosted the students’ mental acuity for just a few minutes, a third test of the effects of Ginkgo intake found that reaction times on one test were improved for up to 6 hours. (5)
Commentary: There is accumulating evidence that Ginkgo biloba can improve mental performance in healthy volunteers, both in short-and long-term studies. For example, a single dose of 120 mg of 50:1 Ginkgo extract was found to optimally improve working memory in volunteers aged 30 to 59 years. (6) A 30-day randomized, double-blind, placebo-controlled clinical trial in which 61 volunteers received 120 mg of 50:1 Ginkgo extract per day found that Ginkgo improved speed of information processing, working memory and executive processing. (7) However, not all studies have been overtly positive. One study found that 120 mg per day of Ginkgo extract for, 5 days only improved the Sternberg memory scanning test in healthy male volunteers, leading the authors to conclude that Ginkgo was largely ineffective in enhancing memory. (8)
The new studies which combine Korean ginseng (which has been known for some time to have cognition-enhancing properties) with Ginkgo have yielded noteworthy improvements on mental acuity. I have used this combination myself before giving lectures and found that it definitely helped to improve focus and fluency. An interesting twist to the story is that a combination of American ginseng (Panax quinquefolium) and Ginkgo gave promising results in the treatment of Attention Deficit Hyperactivity Disorder (ADHD). (9) While the trial design had several flaws, hopefully this study will stimulate further research on this promising combination.
(1.) Wesnes K, Ward T, McGinty A, et al. The memory enhancing effects of a Ginkgo biloba/Panax ginseng combination in healthy middle-aged volunteers. Psychopharmacology (Berl) 2000 Nov:152 (4):353-61.
(2.) Kennedy D, Scholey A, Wesnes K. Differential, dose dependent changes in cognitive performance following acute administration of a Ginkgo biloba/Panax ginseng combination to healthy young volunteers. Nutr Neurosci 2001;4 (5):395-412.
(3.) Scholey A, Harper S, Kennedy D. Cognitive demand and blood glucose. Physial Behav 2001 Jul;73 (4):585-92.
(4.) Moss M, Scholey A, Wesnes K. Oxygen administration selectively enhances cognitive performance in healthy young adults: a placebo-controlled double-blind crossover study. Psychopharmacology (Berl) 1998 Jul;138(1):27-33.
(5.) Kennedy D, Scholey A, Wesnes K. The dose-dependent cognitive effects of acute administration of Ginkgo biloba to healthy young volunteers. Psychophorinacoisgy (Berl) 2000 Sep;151 (4):416-23
(6.) Rigney U, Kimber S. Hindmarch I. The effects of acute doses of standardized Ginkgo biloba extract on memory and psychomotor performance in volunteers. Phytotherapy Research 1999; 13 (5):408-415
(7.) Stough C, Clarke .1, Lloyd J, et al. Neuropsychological changes after 30-day Ginkgo biloha administration in healthy participants. International Journal of Neuropsychopharmacology 2001;4:131-134.
(8.) Moulton P. Boyko L, Fitzpatrick J, et al. The effect of Ginkgo biloba on memory in healthy male volunteers. Physciology & Behavior 2001; 73:059-665.
(9.) Lyon M, Char J, Totosy de Zepetnek J, et al. Effect of the herbal extract combination Panax quinquefolium and Ginkgo biloha on attention-deficit hyperactivity disorder: a pilot otudy. Journal of Psychiatry & Neuroscience 2001; 26(3):221-228.
COPYRIGHT 2002 The Townsend Letter Group
COPYRIGHT 2002 Gale Group
