Gingko biloba is a Chinese herb often used as a dietary supplement to treat memory loss, and could even protect against Alzheimer's. Researchers found significant improvement in verbal recall among a group of people with age-associated memory impairment, who took the herbal supplement ginkgo biloba for six months, when compared with a group that received a placebo.

The UCLA study used positron-emission tomography (PET) and found that for people taking ginkgo biloba, improved recall correlated with better brain function in key brain memory centers. "Our findings suggest intriguing avenues for future study, including using PET with a larger sample to better measure and understand the impact of ginkgo biloba on brain metabolism," said Dr. Linda Ercoli, lead author of the study and an assistant clinical professor at the UCLA Neuropsychiatric Institute.

Further concerns about quality and assurance have been raised: "The research raises questions regarding the significance of supplement quality and treatment duration," said principal investigator Dr. Gary Small, a UCLA professor on aging and director of the Aging and Memory Research Center at the UCLA Neuropsychiatric Institute. "The Food and Drug Administration does not regulate dietary supplements, and the quality of retail supplies varies widely. We used only the highest grade of ginkgo biloba in conducting our research."

Dr. Small also noted that the six-month UCLA study is one of the first to measure the effects of ginkgo biloba over a longer period of time. Most previous studies have measured the effect of the supplement over 12 weeks or less.

The study examined the impact of ginkgo biloba, compared to a placebo, in 10 patients, aged 45 to 75, who did not have dementia but complained of mild age-related memory loss. Four subjects received 120 mg of ginkgo biloba twice daily, and six received a placebo or inactive substance such as a sugar pill.

Researchers used cognitive tests to measure verbal recall and PET to measure brain metabolism before and after the treatment regimen. Magnetic resonance imaging was used to determine regions of interest to be examined by PET.

A study in France, published in the Journal of Gerontology, has revealed interesting results about the role of Ginkgo Biloba extract in the prevention of Alzheimer's disease. Cognitive performance appears to be maintained for longer as a result of long-term treatment with Ginkgo Biloba extract. There also appears to be a positive effect in preventing the occurrence of Alzheimer's disease.

The findings of this study give every reason to believe that long-term treatment with Ginkgo Biloba extract enables cognitive performance to be maintained for longer periods, and indicate that the development of Alzheimer's disease can be prevented.