Most Americans will be eating turkey during their holiday meals. It is common belief that turkey is to blame for the sleepy feeling we experience after our holiday meals, but is there actually any truth behind this turkey tale?
Contrary to popular belief, turkey is not the direct cause for your post-dinner lethargy. Turkey does, however, contain L-tryptophan, an amino acid which has been correlated with sleepiness. L-tryptophan can metabolize into serotonin and melatonin, neurotransmitters that regulate sleep, but to feel the amount of drowsiness often blamed on turkey, you would need to consume L-tryptophan on an empty stomach without any other amino acids or protein. In fact, other meats like chicken and pork contain the same levels of tryptophan, if not more than turkey. The reason you don’t get drowsy from these foods is because they contain other amino acids that cancel out the lethargic effects. Thus, this myth can be debunked.
If Not Turkey, than What?
That lethargic feeling occurring after a large meal is due to a combination of factors. First, it requires a lot of energy to digest a large meal. Blood will be redirected from other organs and the nervous system to help you digest all the food in your stomach. This same goes for foods high in fat because of the energy required to break it down. Additionally, if you plan on drinking alcohol during the festivities, remember that alcohol is a central nervous system depressant that can add to your drowsiness.
The effects of the tryptophan in your turkey are amplified by the consumption of other high carb foods. The mixture of the two causes the levels of amino acids in the brain rise, leading to serotonin synthesis. The result of which causes your body to produce insulin and causes the amino acids needed compete with the sleep-inducing tryptophan to leave the bloodstream, leaving you with a high level of tryptophan in your bloodstream. In the end, the serotonin synthesis is what gives you that lethargic feeling.
Thus, the drowsiness after your meal is due to a combination of factors, not just the turkey.
