Background: Recently, the superior efficacy of hydroponically cultivated red ginseng preparation HRG80® compared to wild growing white ginseng (WG) in preventing stress-induced symptoms related to the daily work situation of healthy subjects was reported. The aim of this study was to compare the effects of HRG80®, WG, and placebo on the electrical activity in the brain of elderly human subjects during relaxation and mental challenges.
Methods: Changes in the electroencephalogram (EEG) frequency ranges of 17 different brain regions were measured after single and repeated administration of HRG80®, WG, and placebo across a four-week randomized, double-blind, placebo-controlled three-armed cross-over trial.
Results: Both red and white ginseng preparations had a strong impact on brain activity, with different effects on various brain regions depending on the mental load during relaxation and cognitive tasks associated with memory, attention, and mental performance. Both ginseng preparations exhibited significant effects on spectral powers compared to placebo, reflecting an activating action. The spectral changes in the quantitative EEG induced by HRG80® indicated an improvement in mood as well as calming effects, evidenced by the modulation of β2 waves, representing changes in GABA-ergic neurotransmission. HRG80® attenuated δ/θ powers during relaxation, suggesting the potential improvement of pathologically enhanced spectral power in aging.
Conclusion: The results of this study suggest that both hydroponically cultivated red and wild growing white ginseng have similar beneficial effects on the cognitive functions of elderly subjects, as reflected by electric brain activity, but their modes of action on the brain are different.
Keywords: Panax ginseng; brain; cognition; discriminant analysis; elderly subjects; quantitative EEG.