Single doses of Panax ginseng (G115) reduce blood glucose levels and improve cognitive performance during sustained mental activity

Reay JL, et al.

Published in Journal of Psychopharmacology

Methodology

Double-blind, placebo-controlled, balanced crossover of single doses of Panax ginseng G115; 10-minute battery of Serial Threes, Serial Sevens, Rapid Visual Information Processing and a mental fatigue visual analogue scale, with blood glucose sampled before, during and after testing.

Key Findings

30 healthy young adults received a single dose of placebo, 200 mg or 400 mg Panax ginseng G115 in a balanced crossover and completed a 10-minute cognitive battery six times in succession starting 60 minutes post-dose. Both doses significantly lowered blood glucose at all three post-treatment measurements (p < 0.005). The 200 mg dose produced the clearest behavioural effects, significantly improving Serial Sevens subtraction performance and reducing subjective mental fatigue at nearly all post-dose time points (p < 0.05), while 400 mg showed weaker effects.

Conclusions

Panax ginseng can improve performance and subjective feelings of mental fatigue during sustained mental activity.

Limitations

Acute single-dose study in 30 healthy young adults only, so nothing can be concluded about sustained use; the higher dose did not follow a clear dose-response, and multiple repeated cognitive measures raise the chance of false positives.