Don't Blame Sleepiness After Turkey Dinner on Tryptophan
The amino acid has gotten a bad rap—but there's more to the story
By Jenn Gidman,  Newser Staff
Posted Nov 26, 2015 9:47 AM CST
Tryptophan's not the only one to blame for your sleepiness.   (Shutterstock)

(Newser) – Succumbing to Mr. Sandman after a hearty turkey dinner isn't tryptophan's fault. At least, not totally, reports the New York Times, which has done its due diligence in compiling plenty of other sources that back up its stop-blaming-tryptophan campaign. The amino acid found in turkey—and long the Thanksgiving whipping boy for inducing fatigue—is indeed a natural sedative that serves as a "building block" of serotonin and melatonin, two brain chemicals that regulate mood and sleep, NPR explains. But it's a myth "based on a little correct information [that's been] misunderstood and misapplied" that the tryptophan found in your holiday turkey is responsible for your sleepiness, a Cornell molecular nutrition professor tells NPR. First, while turkey has about 350mg of tryptophan per 4-ounce serving, Snopes notes, citing the mythbusters book Don't Swallow Your Gum!, chicken and ground beef contain nearly the same amount, and foods like nuts and cheese harbor even more, per the Times.

And the relatively small amount of tryptophan consumed at Thanksgiving dinner is less than what would be needed to bring on sleep (Snopes notes that tryptophan sleep aids typically boast 500mg to 1,000mg). Plus, other proteins absorbed during the meal slow down the absorption of tryptophan. The real issue on Thanksgiving Day: the overload of carbohydrates (e.g., stuffing, yams, potatoes) that people consume. Live Science explains that carbs jump-start the release of insulin, which gets rid of most other amino acids from the body, but not tryptophan, giving it free rein in the body. Drinking too much liquor is another holiday sleep perp. And one reveler tells NPR, "Maybe it's because I'm around my family, so I just want to sleep." Moral of the story? Save the whipping for the Thanksgiving potatoes. (Why are Thanksgiving turkeys these days so darn big?)