I'm pretty sure you've heard of the so-called turkey coma: Tryptophan, an amino acid present in all that turkey you're going to eat tomorrow, makes you sleepy. Heck, it was fodder for a whole Seinfeld episode. And, some of you may have even used it as an excuse to get out of doing the dishes on Thanksgiving.
Though scientists have debunked the tryptophan/turkey myth, the urban legend continues to live on. I decided to turn to Stanford neuroimmunologist Lawrence Steinman, MD, to finally put the turkey talk to rest. Back in 2005, his lab showed that tryptophan plays a pivotal role in the immune system.
So I asked Steinman: If we feel sleepy after eating a big turkey meal on Thanksgiving, is it due to tryptophan (which is allegedly very high in turkey)? He told me:
Humans cannot make tryptophan. Tryptophan is not higher in turkey than in most other muscle tissue from other animals, more commonly known as meats. When we ingest tryptophan, most is metabolized in the liver. However, some tryptophan gets to the brain, where it is metabolized into serotonin and melatonin. This uptake and conversion may take hours. The effects of alcohol are much faster.
It is not the turkey that makes us sleepy at Thanksgiving. It is the massive ingestion of calories, carbohydrates and often alcohol that results in the desire to sleep. Whatever makes you sleepy on the Thanksgiving holiday just enjoy it. Kick off your shoes, stretch out on the couch and watch a football game. Just refrain from snoring or you risk alarming the guests. But please ask someone to wake you from your nap, so you can help with the dishes!
Previously: Wherein we justify eating more cranberry sauce tomorrow and A guide to your Thanksgiving dinner's DNA
Photo by orphanjones