Psychology study yields significant findings on Gingko Biloba supplement

Although Ginkgo Biloba may sound like some crazy creature George Lucas dreamed up, the natural supplement can enhance memory in older individuals, a study conducted by Trish Kaminski, assistant professor of psychology, has found.

“I’m happily surprised and also encouraged that a relatively safe and inexpensive substance can have such a therapeutic effect,” Kaminski said.

Kaminski again decided to study the effects of Gingko Biloba, a natural product produced from the Gingko tree in China and believed to enhance memory functioning, after reviewing her earlier Gingko Biloba study conducted in 1998 on college-age students.

“Those results showed that Gingko Biloba was not effective in this age group,” Kaminski said.

Therefore, the current study examined 40- to 60-year-old individuals because of the decline in blood flow, and thus cognitive functioning, which often accompanies the aging process.

Kaminski explained that Gingko Biloba works in part by thinning the blood and thus increasing blood flow to the brain.

Certain behaviors such as smoking and certain health conditions such as high cholesterol can worsen the blood-flow problem, however.

“My hunch was that the students’ brains were too healthy to benefit from the therapeutic effects of the Gingko Biloba in the earlier study,” she said.

To test her theory, Kaminski and four of her students, Rachel Lillie, ’99, Jen Palo, ’99, Amanda Knerr, ’99, and Shari Allison, ’99, studied 44 individuals, half of whom were given a placebo made of wheat flour and brown sugar.

The other half were given Gingko Biloba, which is readily available in most pharmacies. Kaminski then used a series of activities to test the participants’ logical memory, immediate recall and delayed recall.

For example, participants were read short stories, which they then had to repeat back to the researchers.

“This type of task calls upon the parts of our brain that are used for understanding, organizing and storing long-term, auditory memory,” Kaminski said.

Results indicated that Gingko Biloba was effective in improving participants’ logical memory, immediate recall and delayed recall.

Fifty-three percent of those taking the Gingko Biloba showed a significant improvement in logical memory from their pre-test and post-test scores, and 26 percent showed moderate improvement.

By comparison, only 16 percent of those in the placebo group showed significant improvement; 21 percent displayed moderate improvement, and 63 percent showed no improvement. The findings were all statistically significant.

“We also noticed that every pack-per-day (or more) smoker and every subject reporting high cholesterol improved if they were taking Gingko Biloba,” Kaminski added, noting, however, that the researchers had too few subjects to run statistical tests on this finding.

Interestingly, the report also indicated that the part of a person’s memory used for concentration and attention did not improve as a result of Gingko Biloba.

To determine this, Kaminski employed the Digit Span test, which involves having the participants repeat a series of numbers back to the researchers after the numbers are read to them.

“This type of information is only held in our memories for about 20 seconds,” she explained.

“One explanation for the different findings is that tests like Digit Span are very sensitive to other types of factors (fatigue, anxiety, etc.), which we couldn’t control for in a small study,” she said.

Kaminski plans to publish her results in a peer-reviewed journal, possibly Progress in Neuro-Psychopharmacology & Biological Psychiatry.

As for other research pursuits, Kaminski is currently working on developing an assessment tool for identifying communication, parenting and other relational problems that parent-child dyads possess, which put them at risk for child abuse.

She is also collaborating with Cathy Pederson, assistant professor of biology, and biology major Scott Maurer, ’00, to investigate the differences in the neuro-psychological functioning between women who were traumatized as children and women who were not, and she is testing the effectiveness of a body-image program on elementary school girls.