Seeds of Deception
L-tryptophan is an amino acid, a building block of plant and animal proteins. It is one of the "essential amino acids," those that need to be supplied fiom the diet since it is not manuhctured in the body in adequate amounts. L-tryptophan aids in the production of serotonin, which promotes sleep. The presence of L-tryptophan in milk and turkey explains why these foods have been associated with helping people sleep or relax. L-tryptophan was available as an over-the-counter supplement recommended by doctors and others for "insomnia, premenstrual tension, stress, and depressi~n."~ As L-tryptophan had been used safely for years, the doctors were not yet sure if it was the cause of their patients' disorders. Furthermore, all three cases were from New Mexico. Perhaps there was some local toxin that was the cause. Within two weeks, Gleich learned fiom colleagues that three more patients apparently with the same disease had checked into the Mayo clinic. They were fiom different parts of the U.S. One was already on a respirator in very serious condition. All three had taken L-tryptophan. Gleich phoned the CDC again. He told them that the disease was not limited to New Mexico-it's out and it's deadly. In the meantime, Tarnar Stieber of the Albuquerque Journal became aware of the mysterious disease and its potential link to L-tryptophan. On November 7, in the first of a series of articles that would eventually win her a Pulitzer Prize, she described the disease and the possible cause. Immediately, the calls starting pouring in: others who had taken L-tryptophan were also reporting similar symptoms. Four days afier the article appeared, the FDA sent out "a strong warning to the publicn--stop using L-tryptophan! Wlthin days another 154 cases were reported fi-om around the nation. The FDA responded by issuing a recall-all over-the-countersupplements containing 100 mg or more of L-tryptophanwere to be removed fiom the market. The level of 100 mg was chosen, according to FDA testimony, "because, at the time, the lowest daily intake associated with illness was 150 mg."7