New Brunswick

Sleepy after Christmas dinner? Don't blame the turkey

We all like to sleep after Christmas dinner, but when it comes to inducing drowsiness, science tells us turkey is no different than any other meat — except perhaps sea lion kidneys, says Michael Edwards

Science suggests it may have more to do with carbs, and eating in excess

Turkeys do contain the amino acid tryptophan, but no more than most other meats, says Michael Edwards of Science East. (iStock)

You've gobbled up your last bite of Christmas dinner, loosened your belt a notch and shooed the cat off the couch.

It's nap time.

Just don't blame the turkey for your drowsiness, said Michael Edwards, Director of Strategic Initiatives & Exhibits at Science East. It's more likely because you went for seconds — or had an extra slice of pie, perhaps? The turkey is just a convenient scapegoat.

"We all like to sleep after we eat to excess over the holidays so we kind of like to give that excuse," he said.

'It's not just turkey'

It's true that turkey contains the amino acid tryptophan, Edwards said. And that can cause your melatonin levels to go up, and when your melatonin levels go up, it can make you sleepy.

"But here's the thing," Edwards said. "It turns out that pretty much every kind of meat that you could potentially eat has about the same level of tryptophan, it's not just turkey."

(The kidneys of sea lions, on the other hand, have high levels of tryptophan. Eat those, and you can easily justify your nap, Edwards said.)

What makes you sleepy after Christmas dinner may have more to do with all the carbs on your plate, Edwards said.

Insulin released from pancreas

"When you get a lot of carbohyrdrates going into your blood through your food, then you get insulin released from the pancreas and insulin actually causes things to break down the carbohydrates and it causes there to be lower levels of most amino acids in your blood. One doesn't go down, and that one is tryptophan.  

"So it's an indirect pathway to tryptophan, but turkey is no worse than anything else. It's just that we eat to excess and when we eat to excess, we get sleepy."