First things first – Happy Thanksgiving.
Second things second – one of my favorite nutrition myths seems to rear its head about this time every year:
“Everyone’s going to eat too much turkey at dinner tonight and get sleepy.”
The tryptophan in the turkey meat is usually blamed for the bout of sleepyness, as it causes a release of serotonin (a neurotransmitter that calms the body and regulates sleep). However, many different foods contain the same or higher amounts of tryptophan – per a 200 calorie serving, spinach contains more than twice the amount of tryptophan (1052 mg vs 509.4 mg)! Seafood, duck, eggs, even sesame seeds contain a higher concentration of tryptophan than an equivalent 200 calorie serving of turkey.
What if you go by food weight as opposed to calories? Well, swiss cheese and pork loin both top turkey. Comparing a 100 gram serving of each, the cheese and the pork contain 401 mg and 341 mg of tryptophan, respectively, where turkey only contains 333 mg.
What truly causes the post-Thanksgiving dinner induced delirium is three-fold:
1) An overconsumption of alcohol:
Can’t forget that most people drink beer or wine (or both) in generous quantities during holiday dinners.
2) An overconsumption of food:
Perhaps the biggest factor, overeating causes a tremendous shift in blood distribution in the body, shunting blood away from the periphery and concentrating it around the gastrointestinal organs, where it is requred to provide energy for the digestion of the food. The fact that most people tend to consume an excess of carbohydrates may also contribute to sleepyness as these foods cause an increase in insulin secretion. The insulin spike causes amino acids other than tryptophan to be ferried into muscle cells for cellular repair, leaving a higher concentration of tryptophan in the blood stream. This causes a greater serotonin release, resulting in a sleepier you.
3) The high caloric concentration of the foods consumed:
The higher calorie, fattier foods slow down digestion, requiring more energy to process. This, in turn, reduces how energetic you may feel.
In closing, turkey does not make you sleepy – by itself. Which bodes well for me, since I’ll be munching on a turkey sandwich on my way back from Thanksgiving Dinner.