Every year at the beginning of the holiday season, turkeys are butchered and devoured across the nation. Everyone spends time with family, throws back a few drinks, eats to their hearts content, and then casually passes out on the family room sofa. Consistently, at some point during Thanksgiving dinner conversation, perhaps toward the end as food begins to digest, the topic of tryptophan is often raised. 

 

Tryptophan is an amino acid that is found in many types of meat and other products. An article I found from gizmodo.com explains the process of how your body breaks down your food during digestion. The article states that when the digestion process begins, large amounts of glucose are set loose in to your blood stream, in response your body creates insulin to aid in the absorption of the glucose (unless you have diabetes). The insulin sorts through the amino acids and “works by affecting the uptake of a bunch of amino acids in the body… except for tryptophan.”( Condliffe) Once the tryptophan reaches the brain, it is transformed into serotonin, which in turn is changed into melatonin, both of which result in sleepiness. This proves that tryptophan can indeed cause the onset of tiredness.

As a result, tryptophan has become notorious for being the big sleeping pill of Thanksgiving dinner. Since there is in fact tryptophan in turkey, many people accredit the post dinner nap to the large intake of turkey during the meal, but is turkey really the cause of such massive nation wide lethargy? To answer this question, we must first examine the amount of tryptophan found in turkey and how it relates to other regularly consumed foods. A website I found online ranks food based on tryptophan content per 200 calorie serving. Their list puts Alaskan Native sea lions at the top with 2580mg of tryptophan per 200 calorie serving. So turkey should be close to the top too right? Actually, turkey is ranked 158^th on the list with 448mg of tryptophan per 200 calorie serving. Some other foods with very similar tryptophan content include Duck (449mg), Pork (449mg), Chicken (449mg), and many types of fish (445-447mg). With this information, it could be hypothesized that replacing turkey as Thanksgiving’s main meat with any of the previously mentioned, would create the same effect due to similar tryptophan levels.

 

So then why is turkey singled out as causing so much drowsiness? While the tryptophan in the turkey is what actually makes you tired, the tryptophan could not possibly do it with out aid from carbohydrates. Historically, Thanksgiving is an extremely high calorie meal, chalked full of side dishes, deserts, and alcohol all high in carbohydrates. According to Rebecka Shumann,  when the carbohydrates enter the body, they too cause the creation of insulin. Once this happens, “some amino acids that compete with tryptophan leave the bloodstream and enter muscle cells” (Helmenstine). The increase of insulin causes the other competing amino acids to be targeted, but leaves the tryptophan free to flow through your blood stream. This results in a higher concentration of tryptophan accessing the brain and creates higher levels of serotonin and in turn melatonin, causing the end result of sleepiness. In addition, the high levels of serotonin also create a feeling of happiness, comfort, and relaxation, which of course leads to the tiredness.

 

The high calorie intake during Thanksgiving is what really puts your digestive system to work. According to caloriecontrol.org, “the average American may consume more than 4,500 calories and a whopping 229 grams of fat from snacking and eating a traditional holiday dinner with turkey and all the trimmings.” Obviously this is way over the normal daily calorie intake suggested. More information on Thanksgiving calories can be found on a blog post by Georgie Anne Wayne . With so many calories and a busy/distracted digestive system, it becomes easy to imagine how tryptophan can pass so easily through your body. Just remember to go easy on the sides next year if you don’t want to participate in the infamous post dinner snooze.

Works Cited

Condliffe, Jamie. “Why Your Thanksgiving Meal Makes You Tired.” Gizmodo. N.p., 28

Nov. 2013. Web.  29 Nov. 2013. <http://gizmodo.com/why-your-thanksgiving-

meal-makes-you-tired-5862480>.

 

“Foods Highest in Tryptophan.” Foods Highest in Tryptophan. N.p., n.d. Web. 28 Nov.

2013. <http://nutritiondata.self.com/foods000079000000000000000-1.html>.

 

Helmenstine, Anne Marie, Ph.D. “Does Eating Turkey Make You Sleepy?” About.com

Chemistry. N.p., n.d. Web. 28 Nov. 2013. <http://chemistry.about.com/od/holidaysseasons/a/tiredturkey.htm>.

 

Schumann, Rebecka. “Thanksgiving 2013: Why Does Turkey Make You Tired? 4 Fast

Facts About Tryptophan.” International Business Times. N.p., 27 Nov. 2013. Web. 28 Nov. 2013. <http://www.ibtimes.com/thanksgiving-2013-why-does-turkey-make-you-tired-4-fast-facts-about-

tryptophan-1488202>.

 

“Stuff the Bird, Not Yourself.” The Calorie Control Council. N.p., n.d. Web. 028 Nov.

2013. <http://www.caloriecontrol.org/articles-and-video/feature-articles/stuff-the-bird-not-yourself>.

 

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