Ginkgo biloba for intermittent claudication?

Intermittent claudication is the classic complaint of people suffering from peripheral arterial disease. It’s associated with muscle pain in the leg, which occurs during walking and exercise.

Here’s a critical review from the Cochrane Library on the value of Ginkgo biloba treatment.

First, the details.

• A literature search of Ginkgo biloba extract, irrespective of dosage, vs. placebo to treat intermittent claudication was conducted.
• 14 studies with a total of 739 participants were included.

And, the results.

• 11 studies of 477 participants compared ginkgo to placebo.
• The distance walked until absolute claudication increased insignificantly with ginkgo vs. placebo.
  • 64.5 meters (211 feet) on a flat treadmill at an average speed of 3.2 km/h
• Publication bias leading to missing data or “negative” study results is likely to have inflated the apparent benefit, according to the reviewers.

The bottom line?
“Overall,” concluded the authors, “there is no evidence that Ginkgo biloba has a clinically significant benefit for patients with peripheral arterial disease.”

Distances walked on a treadmill can be approximated to those walked on flat ground by multiplying them by a factor of 3. Therefore, the 64.5 meters (211 feet) of treadmill walking might be a long as 193.5 meters (633 feet), which seems like a significant distance for an elderly person trying to go about their daily activities.

Of course, this distance means nothing if it doesn’t differ from what can be accomplished after taking a placebo. And the Cochrane reviewers indicate that poor study design and execution of these studies make the reported improvement associated with ginkgo suspect.

Interestingly, in 2005, Prof. Ernst, from the Peninsula Medical School, in the UK came to a different conclusion. His review and meta-analysis lead him to report that the results suggest, “Ginkgo biloba is effective compared with placebo for patients with intermittent claudication.”

A PubMed search of studies published between the dates of these 2 reviews revealed only 1 study of ginkgo treatment for intermittent claudication. Researchers from Southern Cross University, in Lismore, Australia support the conclusions of the Cochrane review. They reported that supervised exercise training + ginkgo did not produce greater beneficial effects than exercise training alone.

Drs. Teresa Carman and Bernardo Fernandez of the Cleveland Clinic, in Ohio tell us, “The clinical goals of management include increasing walking distance and improving quality of life.” To this end, “A dedicated, supervised walking program is the foundation of intermittent claudication management.”

Support for this recommendation can be found here in another Cochrane review.

4/17/09 22:14 JR