Effects of Korean red ginseng on human gray matter volume and cognitive function: A voxel-based morphometry study.

OBJECTIVE We aimed to investigate the effects of Korean red ginseng (KRG) supplementation on gray matter volume of the human brain which could be related to cognitive enhancing effects of KRG. METHODS In this randomized, double-blind, placebo-controlled study, 51 healthy individuals were assigned to receive either KRG (1000 mg/day, n = 26) or placebo (n = 25) for 8 weeks. Gray matter volume of the whole brain was measured using voxel-based morphometry based on high-resolution T1-weighted magnetic resonance images acquired at baseline and week 8. The standardized composite cognitive scores of executive function, attention, and memory were also evaluated at baseline and week 8. Changes in gray matter volume as well as the composite cognitive scores were compared between the KRG and placebo groups. RESULTS Following 8 weeks of KRG supplementation, the gray matter volume of the left parahippocampal gyrus increased significantly in the KRG group, relative to the placebo group (p for interaction < 0.001). The KRG group also showed greater magnitude of enhancement in the composite cognitive scores relative to the placebo group (p for interaction = 0.03). CONCLUSIONS Gray matter volume increase in the parahippocampus may be a key neural change as induced by KRG supplementation, which could be associated with cognitive enhancement.