It's hard to believe, but in 2020 Americans ate 5.26 billion pounds of turkey — around 16 pounds per person. If the myth about tryptophan in turkey making you sleepy were true, very few folks would contend with insomnia (up to 30% do). But it's not, even though tryptophan does have special powers. 

Tryptophan, an essential amino acid and building block for proteins, is used by the body to make niacin (vitamin B3), which supports healthy digestion, nerve function, and skin.

It also helps produce the neurotransmitter serotonin, a hormone that affects your brain and guts (it's made both places), helps nervous system cells communicate, and promotes healthy digestion, strong bones, and (yes) sleep.

To top it off, tryptophan helps control body-wide inflammation and uplifts your mood.

Your body's ability to use tryptophan for all that good stuff diminishes with age, and that has consequences, according to a study in the journal Molecular Sciences.

Researchers reported that just eight weeks on a low-tryptophan diet disrupts gut bacteria, triggering higher levels of systemic inflammation and reduced production of serotonin in mice.

They call this an "unnatural" process of aging that's associated in humans with impaired digestive health, declining cognitive function, and a compromised immune system.

Here's your menu for a steady supply of tryptophan and a younger you: canned tuna (27 mg per ounce), poultry (20 mg per ounce in dark-meat turkey, 14 mg per ounce in light-meat chicken), oats (147 mg per cup), whole wheat bread (up to 19 mg per slice), chocolate (up to 18 mg per ounce), and fruits (banana 11 mg, prune 2 mg).