It’s almost here, the third Thursday in November in which most Americans partake by indulging in a feast of turkey, stuffing and pie until we can’t possibly eat any more. While the daytime is typically filled with energetic family and/or friendly get-togethers, more often than not, the evening leaves most of us slumped over on the couch, bellies full, eyelids droopy. Not a bad way to spend a Thursday. Fighting the urge to fall asleep, many ask the same question, what is it that makes us so tired after a big Thanksgiving meal year after year? For years, it has been a common belief that the L-tryptophan contained in turkey makes you sleepy. But are we accusing the wrong culprit? Let’s dive in.
To understand the basics, L-tryptophan is an essential amino acid, the building blocks of proteins. The body can't make it, so our diet must provide tryptophan. Foods rich in tryptophan include, you guessed it, turkey. Tryptophan is also found in other poultry, meat, cheese, yogurt, fish, and eggs. Interestingly, turkey contains no more of the amino acid tryptophan than other kinds of poultry. In fact, turkey actually has slightly less tryptophan than chicken, says Dawn Jackson Blatner, RD, LDN, an American Dietetic Association spokeswoman and author of The Flexitarian Diet.
So we ask again, why does a big Thanksgiving meal make us feel so tired? As it turns out, there is another, more reasonable explanation for why we typically fall into a lazy, exhausted slump after the big meal. The answer? Food coma. Scientifically known as postprandial somnolence, a food coma, or after dinner dip, is a normal state of drowsiness or tiredness following a meal.
As we are eating, the stomach produces gastrin, a hormone that promotes the secretion of digestive juices. As the food enters the small intestine, the cells in the gut secrete even more hormones (enterogastrone) that signal other bodily functions, including blood flow regulation.
But what does this have to do with sleepiness? Well, as we’re digesting our meal, more of our blood is pushed to the stomach and gut, to transport away the absorbed newly digested metabolites. This leaves less blood for the rest of the body and can cause some people to feel a bit 'light-headed' or tired. Still, the body is a lot more sophisticated than that and doesn’t respond to food volume alone.
What you eat is just as important as the size of your meal. In fact, consuming large amounts of carbohydrates and alcohol may be the real cause of a post-Thanksgiving-meal snooze, experts say. Consuming carbs triggers the release of insulin, which removes most amino acids from the blood, except for tryptophan. This allows tryptophan to enter the brain and form serotonin and, ultimately, melatonin. All in all, any big meal containing tryptophan and lots of carbohydrates can trigger sleepiness, not just turkey.
Moral of the story: turkey isn’t the culprit, we (and gluttony) are! So go ahead and gobble up!
This blog provides general information and discussion about medicine, health and related subjects. It is intended for these purposes only and does not address individual circumstances. The words and other content provided in this blog, and in any linked materials, are not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on CurAegis.com. If you think you may have a medical emergency, immediately call your doctor or dial 911.