Answer :Tryptophan is an amino acid found in foods including poultry, peanuts and seeds, soy products, dairy, eggs and fish. Its an essential amino acid, meaning your body cant produce it; you must obtain it from your diet. Popularly, tryptophan is best known for its supposed power to put you to sleep after eating too much Thanksgiving turkey (in reality, all those carbs in the holiday feast are to blame). The body converts tryptophan into niacin and into serotonin, a neurotransmitter that regulates mood, anger and aggression, appetite and some cognitive functions. Antidepressants such as Prozac and Zoloft are selective serotonin reuptake inhibitors (SSRIs), which block the reabsorption of serotonin. When serotonin is converted to the hormone melatonin, it helps you sleep-hence the turkey tale.
When you eat foods containing tryptophan, the body converts some of it to kynurenine, which ultimately produces niacin. Other tryptophan gets converted into another intermediate compound, 5-hydroxy tryptophan (5-HTP).
Tryptophan supplements, once commonly used for insomnia, depression and anxiety, were banned in 1989 after toxic contaminants caused an outbreak of eosiniphilia-myalgia syndrome (ESS), characterized by muscle and joint pain, weakness, fever, swelling of limbs and shortness of breath. Recently, however, supplements of 5- HTP have appeared on the US market, promoted for positive mood and appetite control.
To learn more about tryptophan and 5-HTP, we consulted Erick H. Turner, MD, of the Portland VA Medical Center in Oregon, who authored a comprehensive review of the evidence on 5-HTP and serotonin. I would argue that tryptophan is inefficient compared to 5- HTP, Dr. Turner replied. The idea is to get more serotonin synthesized in the brain. When you eat tryptophan, first of all, the lions share of it goes down the kynurenine pathway (to make niacin), and only a minority goes down the serotonin pathway. With 5-HTP, youre already halfway down the serotonin pathway, so it can only go toward serotonin.
However, you still have to worry about the 5-HTP being converted to serotonin before it gets into the brain, in which case you can get side effects related to serotonins action on various organs (e.g. nausea, flushing). This is not a disadvantage compared to tryptophan-what little tryptophan gets to the 5-HTP step will suffer the same fate. The way to minimize the amount of 5-HTP getting chewed up in the periphery- before it gets into the brain-is to give a peripheral decarboxylase inhibitor (PDI), such as carbidopa, which is available only by prescription.
Nonetheless, Dr. Turner says its plausible 5- HTP supplementation could be effective in treating depression and anxiety, since serotonin is implicated in anxiety disorders as well as depression (and many SSRIs are approved for both).
Eating lots of turkey, however, is unlikely to significantly improve your mood.