Thanksgiving Turkey Tryp(tophan)ing
Last Thursday, some of your relatives undoubtedly blamed their sleepiness on the turkey. Unless you’re related to a struggling dietitian, the famously rumored high tryptophan content was likely used to back the claim. One of the twenty main amino acids, tryptophan is used in the body to produce serotonin and melatonin, both of which are related to tiredness. Though logical, this rumor is false. For one, turkeys have no more tryptophan content than any other meat. Chicken actually has more tryptophan content by weight, but does eating KFC make you tired? If that’s the case, then you are probably just eating too much. The real reasons for that tired feeling after Thanksgiving dinner – and large meals in general – are the large amount of carbohydrates, fats and possibly alcohol that were ingested. It takes energy to digest food, and when there is a lot of food to digest, a lot of energy will be used. On a more biochemical level, when carbohydrates are being digested, insulin is produced and this causes amino acids other than tryptophan to be absorbed into the muscle cells. Even after eating meat, tryptophan levels will not be high enough to cause a noticeable effect, but the insulin induced absorption leaves a high concentration of tryptophan in the blood stream which then causes serotonin and melatonin to be produced, inducing sleepiness. In reality eating a large carbohydrate rich meal will make you just as tired with or without any tryptophan ingested. In addition, ingesting fats increases the time and energy needed for digestion, and alcohol is a depressant for the nervous system. Both of these will therefore only make the consumer more drowsy. So next time – most likely Christmas – a relative incorrectly blames his or her stupor on a specific food, correct them. Or instead, because it’s the holidays, be polite and silently shake your head in shameful disapproval.