Turkey daze...

Do you fall into a satiated stupor after Thanksgiving dinner? Have you heard that eating turkey makes you sleepy? Turkey contains tryptophan, an amino acid often blamed for the post-meal lethargy. The human body uses tryptophan to make serotonin. Studies have shown that serotonin, a type of neurotransmitter, induces sleep in nonhuman mammals and scientists believe it may do the same in humans. But don’t blame the turkey for your drowsy state. To enter the brain, tryptophan must hitch a ride through the blood-brain barrier on specialized protein transporters. Turkey contains five other amino acids in addition to tryptophan, all vying for a ride. Since tryptophan is the scarcest of the amino acids in turkey, it usually loses out in the competition.
What probably makes you sleepy after Thanksgiving dinner is dessert. Carbohydrates increase brain serotonin even though carbs contain no tryptophan. Here’s how: sweet desserts trigger your pancreas to produce insulin, a hormone that helps cells absorb glucose and amino acids. Insulin has little effect on tryptophan, but it does allow your cells to absorb other amino acids. With the others out of the way, tryptophan catches a ride into the brain and steps up the brain’s production of serotonin. Hence, the urge to snooze…
Even in the absence of dessert, you may find yourself nodding off after Thanksgiving dinner. Loading the stomach with food stretches the small intestine, causing sleepiness. All that blood going to the stomach and intestines means less blood for the brain and muscles. And then there are the beverages. Do you enjoy wine or beer with your meal? Drinks containing alcohol can also cause drowsiness. So enjoy Thanksgiving dinner but please don’t blame the bird for your turkey daze!