The Herald Bulletin

November 19, 2012

Turkey tucker-out

Thanksgiving dinner make you sleepy? Blame L-Tryptophan

By Baylee Pulliam
The Herald Bulletin

ANDERSON, Ind. — The turkey’s gone, the table’s been cleared and Dad, Uncle Ted, Aunt Edna and Grandpa are all nodding off watching games on TV.

So what’s to blame for this post-Thanksgiving aftermath? The turkey?

There might be some actual science behind that.

Turkey contains an essential amino acid called L-Tryptophan, which helps the body produce serotonin, said Jenny Martin, nutrition coordinator for Community Hospital Anderson. That serotonin is a building block for the hormone melotonin, which helps the body regulate its sleep and waking cycles.

Put simply, the L-Tryptophan in turkey helps your body decide when to go beddy-bye.

But turkey isn’t the only L-Tryptophan-laden food, nor does it have the highest levels.

“Spinach, eggs, soy and some types of fish contain much higher amounts, and many foods have at least some L-tryptophan in them,” Martin said.

So why do your eyelids droop after a turkey Thanksgiving dinner, but not usually after eating a Greek salad, omelet or tofu stir-fry?

Because the turkey’s got help.

“Thanksgiving dinner includes many carbohydrates: potatoes, breads, stuffing, pie, and alcohol,” said Dr. Michael Bailey, an assistant professor of biology at Anderson University.

Those carbohydrates raise insulin levels in the blood, he said in an e-mail, which “causes the transport of some amino acids into muscles but not tryptophan.”

Because there’s more L-Tryptophan in the blood but the muscles aren’t absorbing it, it goes to the brain.

But there are a lot of other factors that contribute to post-Thanksgiving dinner sleepiness, Bailey said.

For example, there’s the fact that Americans tend to overeat at Thanksgiving. And that might be an understatement.

The average adult consumes roughly 3,000 calories and 229 grams of fat in one Thanksgiving sitting, according to the American Council on Exercise in 2004. To work that off, the average 160-pound person would have to walk about 30 miles.

“The mere process of digestion can be exhausting for the body,” Martin said. “So when we overeat, our body must work much harder to digest all of the extra calories consumed.  Don’t blame the turkey — blame the four plates of food and whole pie you just consumed.”

Then, of course, there’s alcohol. And maybe even the sense of calm that comes after the craziness of dinner-prep, Bailey said.

So how does one avoid dozing off during the holidays?

Simple: don’t overeat. Practice moderation and eat a balanced diet rich in whole grains, fruits and veggies.

It also helps to “get exercise before, during and after the holiday season,” Martin said. “And resist the urge to take that after-meal nap we so want to take.”

But, if you do indulge a bit more than you should, Bailey said it might not be such a bad thing. That is, unless you’re “not helping your spouse clean up in the kitchen because you are sleeping on the couch with a football game playing on TV!”

“It may actually help if you plan to stand in line at midnight” for Black Friday doorbusters, he said. “At least you got some sleep before shopping!”

Find Baylee Pulliam on Facebook and @BayleeNPulliam on Twitter, or call 648-4250.