Dangshen (Codonopsis pilosula) and Bai guo (Gingko biloba) enhance learning and memory

An exploration of the usefulness of several common Chinese herbs used for Acquisition and Retention singly or in combination is required.

To test (1) whether Gingko biloba (Bai guo) in combination with Codonopsis pilosula (Dangshen) or Gingko biloba (GB) alone could enhance memory acquisition and retention of normal human subjects, better than a placebo and (2) to investigate whether the overall health status can be affected by these supplements.

A double blind randomized placebo controlled trial design was used to determine the efficacy of these two products compared to placebo.

Sixty participants, aged 21- 60 years, who were either students or faculty of the Southern California University of Health Sciences.

Each combination capsule was made up of 75mg of Codonopsis pilosula total glycosides and 40mg GB extract. Each GB capsule consisted of 40mg of Gingko biloba as an aqueous extract and. The placebo pill was similar in shape and color to that of the other two capsules. All the participants regardless of the group were instructed to take one pill twice a day with food.

The primary outcome measure was a computerized, standardized acquisition and retention test provided by Digital Acumen, Inc. The secondary outcome measures were the SF-12 and the Medical Symptom Questionnaire ( 1997 healthcomm International, Inc. And Immuno Laboratories, Inc.)

Mean age was 28 years; almost two thirds of the sample were males. The study adopted repeated measure analysis using data from three measurement points for between group analysis. GB group was compared to placebo, and CPG/GB group was also compared to placebo. These individual comparisons were made to determine whether the active products produced better results than chance. The between groups findings indicate that both products are better than placebo at producing improvements in acquisition and retention and overall health status.

In our participant population, the combination product seems to be better than GB alone in improving the cognitive function and overall health.