We’ve either all heard the story that you eat turkey and then you fall asleep, right? It was even spoofed on a Seinfeld episode when Jerry met a woman who had a collection of never-before-opened classic toys that he wanted to play with. He and his friends fed her copious amounts of turkey, she fell asleep and they broke open the Easy Bake Oven, GI Joe action figure and a classic gumball machine.

Is it really true though, that turkey makes you fall asleep? Or is it just all of the other good foods that accompany the meal that contribute to your sleepy feeling after you’ve cleaned your plate? Many people do believe that consuming turkey can make you sleepy, since turkey meat contains high levels of an amino acid known as tryptophan – a precursor for the production of the neurotransmitter serotonin, which has a calming, sleep-inducing effect on the brain.

Until the 1990s, tryptophan supplements were used as a popular sleeping aid until they were banned by the FDA after a batch of contaminated product was associated with many cases of a rare and potentially fatal condition.

But the fact that the turkey is responsible for the Thanksgiving evening slump is a myth. For tryptophan to have a sedative effect, it must be taken on an empty stomach. After you’ve ingested a “modest” Thanksgiving meal of turkey, stuffing, vegetables, sweet potatoes, gravy, rolls, cranberry sauce, and pumpkin pie with whipped cream, you aren’t going to experience any sedative effects of tryptophan in the turkey. Keep in mind that turkey isn’t the only food rich in tryptophan; pork, chicken, and cheese also contain tryptophan, yet these foods have never been associated with unusual or increased sleepiness after consumption.

So what makes you sleepy and lethargic after the Thanksgiving meal? It could simply be that you’ve consumed a larger than normal quantity of food accompanied by a high-carbohydrate feast containing sweets, potatoes, and bread. Alcohol consumption, which typically comes along with the Thanksgiving meal can also add to the sedative effect, especially for those who don’t typically imbibe.

Okay, so it looks like turkey is off the hook on making you fall asleep, right? Could be, but keep this in mind – the average Thanksgiving meal tops out at 3,000 calories! In addition to the turkey, you’re likely eating mashed potatoes, bread, corn-on-the-cob, yams, alcohol, and of course, pumpkin pie. While these foods are certainly delicious, they are also full of carbohydrates and fat and it takes a lot of energy for your body to digest fat. The combination of the large meal and the approximately 200 grams of fat require the body to reroute a large portion of its energy and blood flow to the digestive system where it will spend the next several hours breaking down the meal. All of this work being expended by your body is enough to make anyone sleep. Combine that with the fact that the other amino acids which generally counteract the effects of tryptophan are also leaving the blood to aid in digestion you have the perfect recipe for lethargy.

But go ahead and indulge. It happens one day a year and if you need to nap afterward, find a corner and curl up to relax… until the dessert course is served!

Since 2002, Valley Sleep Center has provided Arizona with diagnostic sleep disorder testing in a home-like atmosphere, ensuring a comfortable, relaxing experience for their patients. Their physicians are Board Certified Sleep Medicine Specialists and are accredited by the American Academy of Sleep Medicine. They provide diagnostic testing for a multitude of sleep-related disorders including insomnia, sleep apnea, snoring, excessive daytime sleepiness, hypertension, sleepwalking and pediatric sleep problems. For information contact Lauri Leadley at 480-830-3900.