Turkey Does Not Make Us Sleepy: The L-tryptophan Myth

We should all get together and make a country in which everybody can eat turkey whenever he pleases.
~Harry S. Truman

There are high levels of L-tryptophanin turkey meat. High levels of L-tryptophanin are found in other poultry, cheese, yogurt, fish, and eggs too. There is more Tryptophan in chicken! For L-tryptophan to actually make you sleepy, it needs to be eaten with an empty stomach, with no other types of amino acids or protein. There is a lot of protein in turkey, and how often does anyone eat just turkey?



There is a sleep connection to turkey. The body uses tryptophan in a multi-step process to make serotonin, a neurotransmitter in the brain that helps regulate sleep. Big meals can cause sleepiness especially if the meal includes a plethora of carbohydrates. Carbohydrate calories stimulate the release of insulin, which triggers the uptake of most amino acids from the blood into the muscles except for tryptophan.

With other amino acids out of the bloodstream, tryptophan can make its way to the brain to produce serotonin more easily. Without an insulin surge, tryptophan would compete with all the other amino acids as they make their way to the brain. And not enough tryptophan would make it to the brain because other basic amino acids are far more plentiful in food.

Note: I still plan to take a nap after Thanksgiving dinner.