How did ginkgo biloba become the top-selling brain enhancer?

A special issue on neuroscience and neuroculture.
April 25 2007 4:35 PM

Ginkgo Biloba? Forget About It.

A history of the top-selling brain enhancer.

Click here for more from the Brains! special issue.

(Continued from Page 1)

The 1997 JAMA study was manna for the herbal supplements industry. The active ingredient in Ginkgold had, as the product's packaging now states, been "clinically proven." But EGb 761 had not been shown to improve mental functioning in healthy adults—only in elderly "demented" adults. This significant detail was conveniently elided in Ginkgold's marketing materials, as well as those of its competitors (many of which use as little genuine ginkgo as possible).

A 1991 French study found some positive effects among healthy young females, but it involved only 12 test subjects. Other studies using more volunteers offered inconsistent results—sometimes ginkgo improved memory very slightly, but the effects inexplicably faded in and out. A British researcher noticed that rats developed more brain receptors after ingesting ginkgo, but his findings "failed to meet the mathematical test for statistical significance."

Advertisement

In 2002, a long-anticipated paper appeared in JAMA titled "Ginkgo for memory enhancement: a randomized controlled trial." This Williams College study, sponsored by the National Institute on Aging rather than Schwabe, examined the effects of ginkgo consumption on healthy volunteers older than 60. The conclusion, now cited in the National Institutes of Health's ginkgo fact sheet, said: "When taken following the manufacturer's instructions, ginkgo provides no measurable benefit in memory or related cognitive function to adults with healthy cognitive function."

The impact of this seemingly damning assessment, however, was ameliorated by the almost simultaneous publication of a Schwabe-sponsored study in the less prestigious Human Psychopharmacology. This rival study, conducted at Jerry Falwell's Liberty University, was rejected by JAMA, and came to a very different—if not exactly sweeping—conclusion: There was ample evidence to support "the potential efficacy of Ginkgo biloba EGb 761 in enhancing certain neuropsychological/memory processes of cognitively intact older adults, 60 years of age and over." The two studies canceled each other out in the court of public opinion; ginkgo sales remained strong.

Conflicting views of ginkgo's memory-enhacing properties are likely inevitable, since it's difficult to measure mental acuity: Every study must rely to some extent on volunteers' impressions as to whether their memories have improved. Analyze enough small sets of such subjective data and you're bound to find evidence to support either position. And if you come down a skeptic, be careful—Schwabe recently sued an Australian consumer watchdog to prevent it from publishing a report critical of EGb 761.

A large-scale, multicenter, multiyear study might clear things up, but no one appears interested in funding such a massive effort. The National Center for Complementary and Alternative Medicine is in the midst of a clinical trial involving 3,000 Alzheimer's patients, but this obviously has no bearing on whether ginkgo can help the healthy.

Regardless, herbal companies will continue to advertise their ginkgo supplements with such watery, asterisked statements as, "May help to support mental sharpness." Starbucks, of course, could reasonably make the same claim.

Brendan I. Koerner is a contributing editor at Wired and a columnist for Gizmodo. His first book, Now the Hell Will Start, is out now.

TODAY IN SLATE

The World

The Budget Disaster that Sabotaged the WHO’s Response to Ebola

How Movies Like Contagion and Outbreak Distort Our Response to Real Epidemics

PowerPoint Is the Worst, and Now It’s the Latest Way to Hack Into Your Computer

Everything You Should Know About Today’s Eclipse

An Unscientific Ranking of Really, Really Old German Beers

Education

Welcome to 13th Grade!

Some high schools are offering a fifth year. That’s a great idea.

Culturebox

The Actual World

“Mount Thoreau” and the naming of things in the wilderness.

Want Kids to Delay Sex? Let Planned Parenthood Teach Them Sex Ed.

Can Democratic Sen. Mary Landrieu Pull Off One More Louisiana Miracle?

  News & Politics
Politics
Oct. 22 2014 9:42 PM Landslide Landrieu Can the Louisiana Democrat use the powers of incumbency to save herself one more time?
  Business
Continuously Operating
Oct. 22 2014 2:38 PM Crack Open an Old One A highly unscientific evaluation of Germany’s oldest breweries.
  Life
Lexicon Valley
Oct. 23 2014 10:30 AM Which Came First, the Word Chicken or the Word Egg?
  Double X
The XX Factor
Oct. 23 2014 11:33 AM Watch Little Princesses Curse for the Feminist Cause
  Slate Plus
Working
Oct. 23 2014 11:28 AM Slate’s Working Podcast: Episode 2 Transcript Read what David Plotz asked Dr. Meri Kolbrener about her workday.
  Arts
Brow Beat
Oct. 23 2014 11:34 AM Louis C.K. Crashes a Brad Pitt Interview on Between Two Ferns
  Technology
Technology
Oct. 23 2014 11:45 AM The United States of Reddit  How social media is redrawing our borders. 
  Health & Science
Bad Astronomy
Oct. 23 2014 7:30 AM Our Solar System and Galaxy … Seen by an Astronaut
  Sports
Sports Nut
Oct. 20 2014 5:09 PM Keepaway, on Three. Ready—Break! On his record-breaking touchdown pass, Peyton Manning couldn’t even leave the celebration to chance.