In 1989, 1,536 people were hospitalized with a rare disease that stemmed from a batch of over-the-counter tryptophan supplements. Was it a result of genetic engineering gone bad, or was the amino acid itself to blame?
Med thumb tryptophan main

It’s the myth that launched a thousand slumbers. Post-turkey drowsiness is caused by tryptophan, the melatonin-inducing essential amino acid, found in the festive fowl. We now know this to be an oversimplified explanation.

However, a far more sinister tryptophan tale endures, one in which over-the-counter supplements of the amino acid, once used to conjure sleep, caused a life-threatening epidemic and provided ammunition for the GMO debate that rages today. 

Early 1970s, Cambridge, Massachusetts

A group of scientists lead by Dr. Richard J. Wurtman, a professor of neuroscience at MIT, has made an important discovery. The team’s research revealed that L-tryptophan controlled the production of serotonin. Wurtman immediately realized the profound benefits an amino acid that increased serotonin levels could potentially hold as an aid to sleep, pain, mood and even appetite. Unfortunately Wurtman’s optimism was unmatched by pharmaceutical companies unwilling to invest money in the quality control studies required to market L-tryptophan as a drug. All was not lost however, at least not yet.

In an FDA snafu at the time, L-tryptophan was placed on a list of safe food substances, effectively opening the floodgates for supplement companies to latch onto this wondrous amino acid. Over the next two decades, despite inadequate testing, companies introduced L-tryptophan to the world in the form of dietary supplements, making it one of the most commonly used health aids in the United States.

Fall 1989, Santa Fe, New Mexico

The warning signs were there. It began with three women exhibiting a shortness of breath, severe muscle spasms and an extremely itchy rash. The symptoms were relatively mundane. Doctors only became worried when they learned all three patients were taking the same L-tryptophan supplement.

It turned out the women had a life-threatening condition called Eosinophilia-Myalgia Syndrome (EMS), a rare disorder known to attack multiple organs in the body, including muscle tissue, skin and lungs. Shortly after being diagnosed, similar cases began to emerge all across the United States, sparking a full-blown epidemic.

On November 17, 1989, following several dozen deaths and more than 1,500 reported instances of EMS, the FDA issued a ban on the suspect L-tryptophan supplement. Consumers who had become dependent on the supplement were soon forced to switch to prescription drugs. Although the importation of all L-tryptophan was restricted at the time, subsequent investigations traced the source of the EMS-inducing pills to a single Japanese manufacturer called Showa Denko KK.

Fall 1989, Tokyo, Japan

Singled out as the culprit, Showa Denko soon came under intense scrutiny, revealing several undisputed facts. Prior to the epidemic, the Japanese manufacturer had made alterations to its manufacturing procedure, reducing the amount of activated charcoal used to purify each batch of tryptophan. The contaminated supply had also bypassed a reverse-osmosis filtration used to remove impurities. In addition, Showa Denko genetically engineered the strain of tryptophan-making bacteria used in the creation of the perilous pill. With so many factors at play, the precise cause of the 1989 EMS epidemic remains uncertain.

While many believe that, because the EMS seemed to only occur in patients who consumed L-tryptophan from Showa Denko, the FDA’s subsequent recall of supplements from all suppliers was less scientific and more politically motivated. Specifically, critics have come to view the FDA’s actions in light of the Showa Denko incident as an attempt to lessen attention of the role genetic engineering played in the epidemic, as to prevent the potentially damning effect this information would have had for the future of biotechnology.

Present Day

Despite remaining a causal link at best, Showa Denko has, in the years since the epidemic, come to represent the apotheosis for anti-GMO activism. Earlier this year for instance, US public interest lawyer Steven Druker devoted a chapter to the manufacturer in his self-published book, "Altered Genes, Twisted Truth: How the Venture to Genetically Engineer Our Food Has Subverted Science, Corrupted Government, and Systematically Deceived the Public.As that hefty title suggests, Druker has some conclusions to share.

“The manufacturer of that particular toxic batch was the only one that was known to have started using genetic engineering in the manufacturing process,” Druker tells us. “The evidence as a whole strongly points towards the genetic engineering as the cause of the toxic contamination.”

According to Druker, the EMS epidemic was caused by an “unknown metabolite” created as a by-product of the genetically engineered bacteria used by Showa Denko, and not the tryptophan itself.  Druker maintains that theories pointing toward tryptophan as the cause are part of a broader conspiracy by the FDA to protect the image of the biotechnology industry. Many in the scientific community beg to differ.

“EMS was present prior to genetically-made Tryptophan — it’s been around for a while,” said Dr. Terry Simpson, a physician and research scientist who spent several years of his career in the field of molecular engineering and viral epidemiology. Simpson was quick to point out that rather than a mysterious toxic metabolite, many peer-reviewed papers have concluded the EMS originated in tryptophan itself.

“It became very clear there was a massive gap between the promotional claims being made by proponents of genetic engineering and the reality.”

“What it looks like is that tryptophan inhibits the breakdown of histamine, a neurotransmitter and common pathway for mast cells (inflammation causing cells prompting EMS reaction),” explains Simpson. “The histamine hangs around longer so people who are more prone to it, tend to have more of a reaction based on larger doses of tryptophan.” The symptoms of EMS, Simpson added, can be reproduced in mice by giving them high doses of tryptophan as an inhibitor of histamine. He also explained, crucially, that, in the years since the 1989 outbreak, the previous “mega-doses” of tryptophan found in supplements have been greatly reduced.

Putting this in perspective, given an individual's own EMS risk factor as a result of genetic predisposition, most of those affected by Showa Denko’s L-tryptophan were found to be consuming 4000 mg of the amino acid a day. Today, following a reassessment of their policy, the FDA recommends a daily allowance of around 1,000 to 1,500 mg.

Despite this fact and a massive amount of scientific evidence refuting Druker’s further claims (“around 600 peer reviewed papers” cites Simpson), the lawyer’s impassioned position largely stems from a series of previously undisclosed FDA records he obtained following a 1998 lawsuit filed against the federal organization.

When Druker found out about the massive effort to reconfigure the genetic form of the world’s food supply, he became concerned.

“As I began researching, it became very clear there was a massive gap between the promotional claims being made by proponents of genetic engineering and the reality,” he says.

Druker points out that regardless of scientific evidence for the health benefits of GMO, the undisputable fact remains that the FDA in at least “ten different instances” has “obfuscated facts” in order to protect the image of genetic engineering. “Genetic engineering is a risky technology. It should not be used to produce any edible products,” he says. “If it’s used in medicine and pharmaceuticals that’s a different situation. In the field of food production the risks are too great and it should not be used.”

As far as Simpson is concerned, while Druker’s claims may contain validity, by rigidly ruling out all GMO technology, he’s throwing the baby out with the bathwater.

The FDA has “obfuscated facts” in order to protect the image of genetic engineering.

“The danger is, people fear GMO because they don’t understand it and as a result GMOs are being taken out of products like cereals,” he says. “But all of the vitamins that fortify the cereal are made from genetically modified bacteria or yeast. So, if you take those out all you have left is the grain much less fortified than before. We’re kind of going back in terms of science to the days when we had vitamin deficiencies, which we’re now seeing again.”

By this point, we’re unlikely to ever truly know the precise cause of the 1989 EMS outbreak. Despite the undoubted truth in many of Druker’s claims, his crusade to bring an end to GMOs in food, largely stemming from the 1989 tryptophan epidemic, seems a lot less justified.

“If you don’t understand something that’s hard to comprehend, you start to create confirmation bias,” said Simpson. “You go where science takes you and if it’s somewhere bad, we admit it and move on — that’s how we progress in science. Politicians and lawyers can never admit they’re wrong and that’s the antithesis of science.”