The only ones still awake within an hour of Thanksgiving dinner were me and the dog. The dog sat hopefully underneath the table, waiting for the weight of the food to bring the whole mess crashing down to her. I sat on the back porch and watched my family sprawled across the living room like the aftermath of an inquest.
It sounds a little suspicious to me to blame the turkey with the contagious fatigue that wipes out the family right before it’s time to do the dishes. After all, I eat turkey sandwiches a few times a week and I haven’t felt the need to settle down for a nap in the dining hall.
Still, I thought, surveying my comatose family, there must be something to this turkey thing. And I’d eaten the ham, so I was still awake enough to dig up the truth. As my family slept and my dog stared down the leftovers, I learned the truth about tryptophan.
Tryptophan is an essential amino acid, one of the building blocks of protein. It is termed essential because the body cannot manufacture it on its own. When tryptophan enters the body in the presence of pyridoxine (B6), it is converted into 5-Hydroxy L-Tryptophan, or 5-HTP. This, in turn, converts into seratonin, a neurotransmitter. Neurotransmitters are extremely important at the neurochemical and physiological level, as they carry impulses between nerve cells. Seratonin can be converted into melatonin, which regulates the sleep wake cycle. Elevated levels of seratonin are credited with relief of depression, reduced pain sensitivity, lessened anxiety and stress and a feeling of calm and sleepiness. Seratonin deficiencies are blamed for depression and insomnia. I recognized that name from the new sleep supplements out there. Hence, I thought to myself, the whole drowsy thing.
Proponents of tryptophan claim it can be used to treat depression, anxiety, insomnia, and bulimia. Studies on its use praise it as the cure for migrane headaches, appetite disorders, over-aggression, and obsessive compulsive disorders. It’s been used to treat nightmares and premenstrual syndrome. The most common use of tryptophan, though, has been as a sleep supplement.
Labels on tryptophan supplements recommended a dosage of 500 to 1500 mg once or twice a day. Experts recommended taking the supplement between meals to avoid the competition between the tryptophan and proteins to get into the blood. Many people also took tryptophan immediately before bedtime.
Natural sources of tryptophan are common and varied. Cheddar cheese, soybeans, pumpkin seeds and sunflower seeds are good sources. Eggs, peas, whole milk and pineapple, not to mention bananas and yogurt, contain relatively high levels of the amino acid. And, of course, there’s the turkey.
Despite the many natural sources, tryptophan was most popular as a bottled supplement when it’s sleep-inducing qualities were first published and marketed. Throughout the 1980’s, tryptophan enjoyed a long, safe history as a popular natural supplement.
However, in the fall of 1989 an outbreak of flu-like symptoms associated with eosinophilic-myalgia syndrome occurred in the United States. ESM is characterized by muscle pain, weakness, and joint pain. It is serious and sometimes fatal. The illness was associated with the use of dietary supplements containing tryptophan. Reported numbers vary, but it is commonly thought that at least 1500 cases of ESM were reported to the Center for Disease Control and 38 people died. The Food and Drug Administration pulled the product off the market in 1990 as the outbreak continued.
Well, I thought. This was a little scary. Does this make all foods with tryptophan in them dangerous? Would I have to watch my sleepy family carefully for signs of muscle pain and weakness? I read further to find that no, we were safe for the moment. The danger occurs when the amino acid is manufactured into a supplement. Investigations into the connection with tryptophan supplements traced the problem to a contaminated batch of the supplement made by a Japanese company. Showa Denko KK had changed its fermentation process to incorporate genetically engineered bacteria and lessened the amount of charcoal used to purify its product. More than 95 percent of the cases of EMS were traced to supplements supplied by this company. However, the FDA did not relax its ban, reasoning that it is still not clear whether manufacturers can produce a supplement that isn’t toxic. Tryptophan is still available by prescription in Canada. Controversy arose in the early 1990’s when the FDA still held its ban; many tryptophan proponents say the amino acid is an effective and safe treatment for many symptoms that high-profile prescription drugs such as Prozac and Zoloft are marketed to treat. They reason that the FDA is supporting the prescription drug companies by refusing to allow the cheaper, more natural tryptophan to compete with expensive psychiatric drugs.
If tryptophan can be found in so many foods, however, then why is it necessary to manufacture it into a supplement? Couldn’t I just increase my banana intake? Apparently not. Tryptophan is the rarest amino acid and is found in relatively small amounts in nature. When ingested naturally, it won’t act on the brain unless the stomach is empty. Other proteins in the system act as competition to get into they system. Tryptophan is also easily destroyed by the liver.
My family, then, would have had to have eaten several more turkeys than they did in order to be excused for their lengthy mid-day nap. If the tryptophan found in turkey was not responsible, then why did I have a houseful of sleeping relatives?
Current research shows that rather than amino acid villainy, what was occurring in my house right now was the result of overeating and too much alcohol. My dog and I had dined relatively lightly and had avoided the wine, which explained our alertness. Also, ingesting large amounts of carbohydrates can be a drain on your energy level, and the digestion process itself draws blood away from the brain, causing fatigue. So more likely than not, my dozing family was sleeping off an indulgence in good food and well-being, rather than being strung out on a tryptophan high. And I figured it was up to me to explain it to them so they’d never use that excuse again.