It's Thanksgiving canon at this point: eat turkey, get tired. One of the greatest pieces of Thanksgiving lore is the presumption that eating turkey makes you super sleepy. That's thanks to a component called tryptophan, the ingredient in turkey with supposedly snooze-inducing powers. But if tryptophan can really help you sleep, why don't we spend the rest of the year having a late-night snack of dark meat instead of painstakingly trying dozens of supplements to help us get some shut-eye? (Side note: White meat isn't nearly as tasty—just sayin'.)
Turns out, everything we thought we knew about turkey making us sleepy is probably a lie. We went to Lindsey Bristol, Swanson’s in-house dietitian, to find out once and for all: Does turkey make you sleepy?
What Is Tryptophan Anyway?
There are 22 total amino acids, and nine of those are considered essential, meaning your body can't produce them, so you need to get them through your diet. Tryptophan is one of the essential amino acids and plays an important role in stress and mood (more on that in a moment).
Tryptophan and Your Brain
If you were to believe the myth, turkey is basically the spindle prick of the Thanksgiving feast, capable of making you nap for hundreds of years. (Okay, a bit dramatic, but you get where we're going with this metaphor.)
"The idea of turkey making you sleepy comes from the fact that it contains tryptophan, an essential amino acid the body uses to make niacin (a B vitamin) and serotonin," Bristol says. Serotonin is also a precursor to melatonin, which is the hormone that helps regulate your circadian rhythm. Basically, melatonin production signals to your body that it's time to go to sleep. And it's tryptophan's involvement in melatonin production that gives it its reputation for making you sleepy.
Turkey is far from the only food to contain tryptophan. Foods like chicken, cheese, eggs, and oats also contain this amino acid, says Bristol. So why don't we feel exhausted after eating eggs in the morning or a chicken breast for dinner? After all, turkey isn't even one of the top 50 tryptophan-containing foods. For turkey alone to make you start to feel drowsy, you'd have to eat around 12 ounces of it, and with all the other delicious food to eat at Thanksgiving, there's no way that's happening. That's at the low end of the estimate, getting you about one gram total of tryptophan, which is the amount you would need to consume to get drowsy, according to one study.
Why the Post-Thanksgiving Sleepiness?
"The typical over-indulgence that comes with Thanksgiving is most likely the real culprit of your urge to snooze," Bristol says. Instead of blaming the turkey, blame the excess of sugar and starches. Plus, when you eat more than you normally do, your body has to divert more resources into digesting all that food, which can account for some of the sluggishness.
She recommends keeping an eye on your portion sizes, drinking tons of water, and taking a walk post-feast in order to keep yourself from feeling exhausted.
Now that we've demystified tryptophan, here's the lazy girl's guide to a post–Turkey Day detox.