Recently, the Food and Drug Adminstration (FDA) cleared the shelves of any product that contained large doses (more than 100 milligrams) of manufactured L-tryptophan. Recent
cases of severe, disabling illness and the deaths of 20 L-tryptophan users, however, have now led the FDA to order a recall of any product containing the manufactured form of
this amino acid.
The recall does not include L-tryptophan taken from natural ingredients such as powdered milk, whey, soy or egg preparations, however. Specialized infant formulas and prescription
intravenous and oral solutions used for people who are unable to eat solid foods are also excluded from the recall, since no cases of L- tryptophan syndrome caused by liquid
nutrition have been reported.
Consumers need to beware, as labels for L-tryptophan tablets and powders can be misinterpreted. Any product that does not clearly state that its L-tryptophan comes from milk
powder, egg protein or soy powder should be avoided. Even products labeled "natural" may still contain manufactured L-tryptophan. Also, since the recall is voluntary, consumers
should be aware that unscrupulous or ignorant vendors may still sell the products.
As you may know, amino acids are the building blocks of proteins. L-tryptophan is one of the 20 known amino acids required by the body. Of those 20, eight, including L-tryptophan,
are termed essential amino acids, since they must be supplied through the diet for proper growth and maintenance of your body. The 12 remaining "nonessential" amino acids can be
manufactured in your body when you ingest adequate amounts of protein.
L-tryptophan occurs naturally in foods that are high in protein, such as milk, beef, eggs and beans. A typical glass of milk contains 126 milligrams of L-tryptophan; a large egg
contains 112 milligrams. Foods containing L-tryptophan also contain a balance of most of the amino acids. In the majority of cases of L- tryptophan syndrome, the sufferers reported
supplement use of the single amino acid in the range of 1,500 to 3,000 milligrams or more.
L-tryptophan, along with other supplements, is sold in health food stores and drug stores without a prescription. Users take the supplement on the advise of friends, self-proclaimed
experts and even doctors, who claim it to be an effective, natural, nonaddictive alternative to tranquilizers for anxiety and sleeplessness. People who take L-tryptophan often
believe unconfirmed studies that it can induce sleep, enhance muscle growth, reduce obesity, relieve stress and negate symptoms of premenstrual syndrome.
L-tryptophan syndrome has been linked to a painful disorder known as eosinophiliamyalgia syndrome, or EMS. The symptoms of EMS include extreme pain in muscles and joints, coughing,
rashes, hardening of the skin, fever and, in extreme cases, death. Federal investigators have yet to determine the cause of the syndrome, but they suspect a contaminant was
introduced during manufacture or packaging. Manufactured L-tryptophan is harvested by fermentation using genetically altered bacteria.
Three theories have been proposed by investigators as to why some L-tryptophan users develop this severe, debilitating illness. The first is that some batches of the amino acid were
contaminated. Some batches may have been improperly produced, resulting in impure, flawed versions of the amino acid that could cause damage as it is processed by the body.
The second theory is that the users who got ill simply overdosed on the supplement. Supplements deliver unnaturally high doses of L-tryptophan, which is normally digested slowly and
in conjunction with other amino acids. Some individuals may be unable to rid themselves of the excess L-tryptophan, causing the buildup of by-products of the compound.
The third theory is a combination of the first two: contamination plus overdose.
Whatever the cause, physicians are pleased with the recall and hope consumers will become more cautious about the indiscriminate sale and use of nutritional supplements. Excessive
intake and levels of any nutrient are harmful to the body. The general public needs to become cognizant of the potential dangers of self-prescribed supplement use to learn that the
way to good health and performance is through regular exercise and a healthy diet. There really is no quick fix.
As this recent supplement scare has shown us, people who think they can improve function and enhance performance with supplement mega-doses run a great health risk. Buyer beware.