By Nick Salazar

Tryptophan (also known as L-tryptophan) is a "colorless, solid, essential amino acid, formed from proteins by the digestive action of the enzyme, trypsin. [It takes 60 molecules of tryptophan to form a single molecule of niacin, more popularly known as vitamin B3 (http://www.americahealth.com/B3.html).] (??) Until recently, tryptophan was being used as a safe, non-addictive medication to promote sleep. The Food and Drug Administration in late 1989 discontinued the use of L-tryptophan. The FDA did this because of reports that it caused severe illness in some people, characterized by muscle pain, weakness, swelling of the arms and legs, fever, and skin rash" (http://www.webmd.com/content/dmk/dmk_article_1459831).

The above excerpt is not comprehensive in its relation of the facts. Thirty-seven people died and 1500 more were permanently disabled as a result of ingesting tryptophan in late 1989 (http://www.gene.ch/gentech/1997/Nov-Dec/msg00120.html). However, they were not ingesting ordinary tryptophan. The people who were affected by the tryptophan in 1989 were ingesting a special form of genetically engineered tryptophan, unbeknownst to them.

In addition to being employed as a sleep-promoting medication, tryptophan was manufactured and sold as a food supplement. A fermentative process was one of the methods used to manufacture it. In this method, appreciable quantities of tryptopahn-producing bacteria are cultured in vats, and then the tryptophan is extracted from the bacteria and purified. During the latter portion of the 1980’s a company named Showa Denko K.K. opted to employ genetic engineering in order to augment and amplify the tryptophan biosynthesis, i.e., the amount of tryptophan produced by the bacteria.

The genetically engineered bacteria produced the desired increased amounts of tryptophan, and Showa Denko shortly thereafter placed the resulting genetically engineered tryptophan on the market. Furthermore, according to U.S. law, they were not required to test their new genetically engineered tryptophan, because for years they been marketing and selling non-genetically engineered tryptophan without ill effect. In other words, the law viewed the old and new tryptophans as equivalent substances.

Yet, within a few months, the genetically engineered tryptophan caused 37 deaths and permanently disabled 1500 people. Upon inspection, it was found that the genetically engineered tryptophan contained toxic contaminants, the most prominent of which was called EBT. EBT made up less than 0.1% of the total product weight, and yet was able to cause death. These toxic contaminants were most likely the result of reactions between tryptophan molecules themselves and tryptophan precursors. Furthermore, these contaminants were chemically similar to tryptophan itself, which would explain why they were not excised from the tryptophan during the purification process. The most likely cause of these reactions was the much higher concentration (due to the augmented biosynthesis) of tryptophan and tryptophan precursors. Unfortunately, scientists cannot be absolutely sure about the cause because Showa Denko destroyed all stocks of the genetically engineered bacteria when the toxicity problems first arose.

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