Why eating turkey really makes you sleepy

Is everyone's favorite Thanksgiving centerpiece really to blame for the post-dinner doldrums?

  • Americans kill around 45 million turkeys every year in preparation for the Thanksgiving meal, only to blame our favorite centerpiece for the following food comas.
  • Rumor has it our after-dinner sleepiness results from the tryptophan found in turkey.
  • However, it is the meal's overall nutritional imbalance, not just the tryptophan, that make us want to leave the dishes for tomorrow. Or maybe the next day.

The turkey is one of the closest living relatives to avian dinosaurs, but recent evolutionary turns has taken it from peak predator to meek entrée. Americans kill about 45 to 46 million turkeys in preparation for Thanksgiving, and to really rub it in, our nation's leader pardons one every year as a lark.

But ignominy doesn't stop there. Through selective breeding, we've dramatically increased the size of turkeys, particularly in the breast for more of that coveted white meat. This has led to all sorts of health issues, including skeletal problems, cardiac morbidity, and reduced immune response. Thanks to those robust breasts, domestic turkeys can't mate anymore and rely on us for artificial insemination.

If that wasn't bad enough, every year after we've feasted on millions of these birds, we then blame them for making us miserably tired. We've even developed a term for it: the turkey coma, the "inevitable and unavoidable nap that occurs about 45 minutes after gorging one's self on a Thanksgiving Day turkey," as one Urban Dictionary user defined it.

But are turkeys really to blame for the turkey coma? And if so, how do they manage this posthumous revenge?

Tryptophan-tasitc meal

Jerry and George use a turkey's tryptophan to make Celia fall asleep in the episode "The Merv Griffin Show."

(Photo from NBCUniversal)

Jerry and George use a turkey's tryptophan to make Celia fall asleep in the episode "The Merv Griffin Show."

As any Seinfeld fan can tell you, that stuff in turkey that makes you sleepy is tryptophan. Specifically, L-tryptophan, an essential amino acid that our livers synthesize into niacin. Niacin, in turn, helps create the neurotransmitter serotonin.

Our brains and bodies use serotonin for many functions. It plays a role in appetite, emotional stability, motor skills, and cognitive processes, but it's most famous for regulating our body's sleep-wake cycles. This common knowledge serves as the basis for the belief that turkey makes you sleepy.

Thing is, a lot of foods contain tryptophan. Nuts, soy, eggs, milk, salmon, chicken, spinach, yogurt, and chocolate are all dietary sources of tryptophan, with many of them containing more tryptophan than our favorite holiday fowl.

According to My Food Data, turkey has 404 milligrams of tryptophan per 100 gram serving. But in the same serving size, pumpkin and squash seeds have 576 milligrams, soybeans have 575, and reduced fat mozzarella has 571. None of these is associated with drowsiness, and nuts are a go-to for an afternoon pick-me-up snack.

Either turkey is being unfairly maligned or something else is weighing down our eyelids after a Thanksgiving meal.

Caloric cat nap

While Seinfeld may have exaggerated the effects of tryptophan, the show did get one thing right. If you want to put your girlfriend to sleep so you can play with her antique toy collection, a calorie-laden meal of turkey, heavy gravy, and a whole box of red wine will do the trick.

Americans consume a lot of calories during a Thanksgiving meal. This isn't news but the numbers, once laid bare, can still be guilt-inducing. The Calorie Control Council estimates that the average Thanksgiving meal weighs in at 3,150 calories, but it's worth noting that their estimate uses sweet tea as a beverage benchmark and not beer, wine, or cocktails.

Dietitian Tanya Zuckerbrot told Fox News that a turkey day dinner ranges between 3,000 and 4,500 calories. Like the Calorie Control Council, her estimate does not include alcoholic drinks, but she also skipped on appetizers.

Obviously, these numbers vary depending on the food available and serving sizes. But any estimate will have one thing in common: a single meal sporting well over the USDA recommended daily caloric intake for all demographics outside of Olympian athletes.

Putting the sleep turkey myth to rest

(Photo by Chen Mengtong/China News Service/VCG via Getty Images)

Two male turkeys named Peas and Carrots sent by the National Turkey Federation (NTF) to the White House are seen before the upcoming annual turkey-pardoning ceremony on November 19, 2018 in Washington, DC.

And this is why the term "food coma" is much more apt — or, if you want to get clinical, "postprandial somnolence."

"We've known for many years that meals with an imbalance of nutrients — that are rich in either fats or carbohydrates — are associated with feeling sleepy," writes Angus Steward, senior lecturer of nutrition and dietetics at Edith Cowan University. "But this is not the case when nutrients are balanced or the meal is rich in protein."

When we start our Thanksgiving meal, our stomachs begin producing a hormone called gastrin. Gastrin kickstarts the digestive process, which reroutes blood to our stomachs to carry away the newly formed nutrients.

Part of the drowsiness is due to the volume of food you consume. It simply takes longer to digest, requiring your body to take it easy while it diverts blood from other bodily functions. But as Steward explains, it isn't just volume at work here. It's also what we eat.

Thanksgiving meals are heavy in fats and carbohydrates. Carbs release glucose into the bloodstream quickly, causing a spike in insulin production. Insulin helps the body absorb the glucose, but in doing so, it makes it easier for tryptophan to pass the blood-brain barrier. Once tryptophan is in the brain, it begins conversion to serotonin to tell your body it's time to sleep.

With your body and mind at rest, your body can get to work absorbing the massive meal.

That's the bad news if you still have a daunting pile of dishes to clean Thanksgiving evening. The good news, as the National Sleep Foundation points out, is that you can use your newfound understanding as a little bio-hack. Eating small bedtime snack that contains both carbs and tryptophan, such as peanut butter on toast, can help you ease into a restful night's sleep.

Ending the blame game

So, the myth is partially right; turkey does have a role to play. It and many other Thanksgiving favorites provide you with ample tryptophan. When combined with an overall high-calorie meal and enough stuffing to carb-load for a marathon, the result is a mid-afternoon snooze.

But the turkey is hardly the sole cause of anyone's sleepiness. If anything, we only have ourselves to blame and can stop blaming it for those decisions. And even if turkey did make us sleepy, let's face it: it has far more grievances against us than we do against it.

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Want to forge stronger social bonds? Bring beer.

New research shows that a healthy supply of locally-sourced beer helped maintain Wari civilization for 500 years.

Culture & Religion
  • A new analysis of an ancient Wari brewery suggests chicha helped maintain the civilization's social capital for hundreds of years.
  • Civilizations throughout the ancient world used alcoholic drinks to signify kinship, hospitality, and social cohesion.
  • The researchers hope their findings will remind us of the importance in reaffirming social institutions and sharing cultural practices — even if over coffee or tea.

Beer is history's happiest accident. Though the discovery probably happened much earlier, our earliest evidence for beer dates back roughly 13,000 years ago. Around this time, the people of the Fertile Crescent had begun to gather grains as a food source and learned that if they moistened them, they could release their sweetness to create a gruel much tastier than the grains themselves.

One day a curious — or perhaps tightfisted — hunter-gatherer hid his gruel away for a safekeeping. When he returned, he found the bowl giving off a tangy odor. Not one to waste a meal, he ate it anyway and enjoyed an unexpected, though not unpleasant, sensation of ease. By pure happenstance, this ancestor stumbled upon brewing.

That's one possible origin story, but we know that our ancestors learned to control the process, and beer took a central role in Fertile Crescent civilizations — so central that Professor Patrick McGovern, a biomolecular archaeologist at the University of Pennsylvania, argues that beer, not bread, incentivized hunter-gatherers to relinquish their nomadic ways.

Beer may also be proof of a God who wants us to be happy (Dionysus?), because the beverage* would be independently rediscovered by peoples across the ancient world, including those in China and South America.

One such peoples, the pre-Inca Wari Civilization, made beer, specifically chicha de molle, a critical component in their religious and cultural ceremonies. In fact, a study published in Sustainability in April argues that the role was so important that beer helped keep Wari civilization intact for 500 years.

Brewing social capital

Twenty years ago, a team of archaeologists with the Field Museum of Natural History, Chicago, discovered a brewery in Cerro Baúl, a mesa in southern Peru that served as an ancient Wari outpost. The brewery contained original equipment, clay storage vessels, and compartments for milling, boiling, and fermentation.

The team recently analyzed these on-site vessels to uncover the secrets of the Wari brewing process. Removing tiny amounts of material found in the spaces between the clay, they were able to reconstruct the molecules of the thousand-year-old drink. They then worked alongside Peruvian brewers to recreate the original brewing process.**

Their molecular analysis revealed several key features of the beer: The clay used to make the vessels came from a nearby site; many of the beer's ingredients, such as molle berries, are drought resistant; and though alcoholic, the beer only kept for about a week.

These details suggest that Cerro Baúl maintained a steady supply of chicha, limited by neither trade nor fair weather, and became a central hub for anyone wishing to partake. The Wari would likely make such trips during times of festivals and religious ceremonies. Social elites would consume chicha in vessels shaped like Wari gods and leaders as part of rituals attesting to social norms and a shared cultural mythology and heritage.

"People would have come into this site, in these festive moments, in order to recreate and reaffirm their affiliation with these Wari lords and maybe bring tribute and pledge loyalty to the Wari state," Ryan Williams, lead author and head of anthropology at the Field Museum, said in a release. "We think these institutions of brewing and then serving the beer really formed a unity among these populations. It kept people together."

The Wari civilization was spread over a vast area of rain forests and highlands. In a time when news traveled at the speed of a llama, such distinct and distant geography could easily have fractured the Wari civilization into competing locales.

Instead, the researchers argue, these festive gatherings (aided by the promise of beer) strengthened social capital enough to maintain a healthy national unity. This helped the Wari civilization last from 600 to 1100 CE, an impressive run for a historic civilization.

Bringing people together (since 10,000 BCE)

A Mesopotamian cylinder seal shows people drinking beer through long reed straws. Image source: Metropolitan Museum of Art.

Of course, the Wari weren't the first civilization to use beer to reaffirm bonds and maintain their social fabric. Returning to the Fertile Crescent, Sumerians regarded beer as a hallmark of their civilization.

The Sumerian Epic of Gilgamesh tells of the adventures of the titular hero and his friend Enkidu. Enkidu beings as a savage living in the wilderness, but a young woman introduces him to the ways of civilization. That orientation begins with food and beer:

"They placed food in front of him,
They placed beer in front of him,
Enkidu knew nothing about eating bread for food,
And of drinking beer he had not been taught.
The young woman spoke Enkidu, saying:
"Eat the food, Enkidu, it is the way one lives.
Drink the beer, as is the custom of the land."
Enkidu ate the food until he was sated,
He drank the beer — seven jugs! — and became expansive
and sang with joy.
He was elated and his face glowed.
He splashed his shaggy body with water
and rubbed himself with oil, and turned into a human
."

Tom Standage, who recounts this scene in his History of the World in 6 Glasses, writes: "The Mesopotamians regarded the consumption of bread and beer as one of the things that distinguished them from savages and made them fully human." Such civilized staples not only demarcated their orderly life from that of hunter-gatherers, they also served a key role in their culture's unifying mythology.

Furthermore, Standage notes, Sumerian iconography often shows two people sipping from waist-high jars through reed straws. The earliest beers were consumed in a similar fashion because technological limitations prevented baking individual cups or filtering the beverage. But the Sumerians had the pottery skills to make such cups and filter the dregs. That they kept the tradition suggests that they valued the camaraderie brought by the experience, a sign of communal hospitality and kinship.

The ancient Greek's similarly used alcohol as a means of maintaining social and political relationships — though their drink of choice was wine.

During symposiums, upper-class Greek men would gather for a night of drinking, entertainment, and social bonding. In Alcohol: A history, Rod Phillips notes that symposiums were serious affairs where art, politics, and philosophy were discussed throughout the night and could serve as rites of passage for young men. (Though, music, drinking games, and sex with prostitutes may also be found on the itinerary.)

Of course, we can amass social capital without resorting to alcohol, which has been known to damage social relationships as much as improve them.

In the 17th century, London's coffeehouses stimulated the minds of thinkers with their caffeine-laden drinks, but also served as social hubs. Unlike the examples we've explored already, these coffeehouses brought together people of different backgrounds and expertise, unifying them in their pursuit of ideas and truths. Thus, coffeehouses can be seen as the nurseries of the Enlightenment.

Relearning ancient lessons

The Field Museum archaeologists hope their research can help remind us the importance social institutions and cultural practices have in creating our common bonds, whether such institutions are BYOB or not.

"This research is important because it helps us understand how institutions create the binds that tie together people from very diverse constituencies and very different backgrounds," Williams said. "Without them, large political entities begin to fragment and break up into much smaller things. Brexit is an example of this fragmentation in the European Union today. We need to understand the social constructs that underpin these unifying features if we want to be able to maintain political unity in society."

So, grab a beer or coffee or tea, spend some time together, and raise a glass. Just try not focus too much on whether your friend ordered Budweiser's swill or an overpriced, virtue-signaling microbrew IPA.

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