Is Turkey to Blame for the “I Need a Nap” Feeling After a Thanksgiving Feast?

Marinated Fig Relish with Olives and Peppers

Thanksgiving plans and prep are underway. My inbox is flooded with messages such as “time to order your turkey,” “plan the best friendsgiving ever,” and links to recipes for pies, sides and more. 

My family isn’t the only one who celebrates with a table overflowing with “must-have” dishes, but what’s on the table may be different this year as increasing food costs challenge budgets

 “Holiday Shopping” research from The Hartman Group and Food Marketing Institute (1,2) revealed that 71% of consumers are adjusting their holiday meal shopping with strategies such as looking for deals (28%), shopping for store brands (21%), making fewer dishes (17%) and asking guests to contribute a dish (17%). Turkey, arguably the star of the table has increased in price 73% over last year to $1.99 (up from $1.15 last year) for an 8-16-pound bird (3).

Turkey is staying in my grocery cart. I want to see that beautifully bronzed bird on my Thanksgiving table and will use every bit of it – including turning the bones into a rich broth for a post-holiday soup.  

Turkey is a good value, nutritionally speaking. It’ an excellent source of protein, B vitamins, choline, and minerals such as selenium and zinc. (4) It’s also a top food source of the amino acid tryptophan, a reason turkey is often blamed for making one groggy after a feast. I share the 411 on that notion in an article I wrote for Valley Fig Growers (5).

As I explain in the article, tryptophan is essential for making make the “feel good” neurotransmitter serotonin which plays a part in cognitive function, and helps regulate mood, appetite, and sleep. The body uses serotonin to make melatonin, often called the “sleep hormone.” Melatonin has many functions in the body –  the best-known is helping to regulate the body’s circadian rhythm and synchronize our sleep-wake cycle with night and day.

It’s easy to assume that because turkey is a top food source of tryptophan it causes post-feast sleepiness. It may be a factor, but scientists don’t think an increase in serotonin production is the main culprit. For tryptophan to enter the brain to make serotonin, it must cross the “blood brain barrier.” To do so it competes with several other amino acids for “a ride” on the same transporter protein.

After an ordinary meal, a modest amount of tryptophan enters the brain (9,10,12). After a Thanksgiving feast however, the abundant carbohydrate-rich foods – rolls, stuffing, cranberry sauce, pie – trigger the pancreas to release insulin which promotes the uptake of amino acids (except tryptophan*) and carbohydrates into skeletal muscles, paving a way for more tryptophan to enter the brain.

*Most tryptophan in the bloodstream is bound to albumin so it isn’t shunted into tissues after a carb-rich meal like the amino acids it competes with for entry into the brain.

Another cause of drowsiness is the fact that large meals stretch the  gastrointestinal (GI) tract and trigger the parasympathetic nervous system into “rest and digest” mode. It slows the heart rate and blood pressure, shunts blood away from the brain and other tissues to the GI tract and increases digestive juices (11).

And, as the chart in my Valley Fig article (5) shows, many foods are rich in tryptophan, and they don’t cause sleepiness. To sum it up, there’s no reason to take turkey off your table. It plays well with this marinated fig relish, shown with dark Mission figs but equally good with Golden figs. Use leftover relish (slice the figs and olives first) on sandwiches and in salads.  

Marinated Figs with Olives and Peppers

Recipe adapted from Herb Marinated California Figs (13).

8 ounces Dried California Figs, Mission or Golden, stems removed

Kosher Salt

¼ cup balsamic vinegar

¼ cup extra virgin olive oil

1 cup pitted Castelvetrano or Kalamata olives

½ cup chopped or sliced drained roasted red peppers such as Mama Lil’s

2 tablespoons chopped fresh rosemary

2 cloves garlic smashed

Freshly ground black pepper

1. Place figs in a medium saucepan. Cover with water; add a pinch or two of salt. Top with lid, placed slightly ajar. Bring to a boil over medium heat, reduce heat and simmer for 30 seconds. Remove from heat. Cool.
2. Drain figs and place in a bowl. Add vinegar and ¼ teaspoon salt.  Stir to dissolve salt.  Add olive oil, olives, peppers, rosemary, and garlic. Add freshly ground pepper and more salt, olive oil and vinegar, if desired. 
3. Cover and chill for several hours or, for best flavor, overnight.
4. Serve with roasted turkey, or slice figs and olives and use on sandwiches or in salads.

References

ONE

FMI Plans for the Holiday Report. The Hartman Group. October 25, 2022.

TWO

Grocery Shopper Trends: Holiday Shopping. Food Marketing Institute.

THREE

Turkey prices are 73% higher than last year and might stay that way through Thanksgiving, commodities strategist says. Aditi Shrikant. CNBC.com.October 18, 2022.

FOUR

All You Need to Know About Turkey Meat. Sharon O’Brien MS, PGDip. Healthline.com. July 15, 2019.

FIVE

Dried Figs + Foods Containing Tryptophan. Lorelle Del Matto, MS, RDN. Valleyfig.com. October, 2022.

SIX

Tryptophan Metabolic Pathways and Brain Serotonergic Activity: A Comparative Review. Erik Höglund, Øyvind Øverli and Svante Winberg. Frontiers in Endocrinology. (Lausanne). 2019; 10: 158.April 8, 2019.

SEVEN

Physiology of the Pineal Gland and Melatonin. Anna Aulinas, MD, PhD. National Library of Medicine. December 10, 2019.

EIGHT

Assessment of the Potential Role of Tryptophan as the Precursor of Serotonin and Melatonin for the Aged Sleep-wake Cycle and Immune Function: Streptopelia Risoria as a Model. Sergio D. Paredes,¹ Carmen Barriga, Russel J. Reiter, and Ana B. Rodríguez.International Journal of Tryptophan Research National Library of Medicine. 2009; 2: 23–36. January 14, 2009. 

NINE

Top Foods High In Tryptophan Webmd.com

TEN

Does Turkey Make You Sleepy? Stop blaming the bird for your turkey daze. Coco Ballantyne. Scientific American. November 21, 2007

ELEVEN

Parasympathetic Nervous System Functions. Olivia Guy-Evans. Fact checked by Saul Mcleod, PhD. Simplypsychology.org May 18, 2021. 

TWELVE

What is Tryptophan? Joy Summer, Dr. Anis Rehman. Updated June 17,2022. The Sleep Foundation.  

THIRTEEN

Herb Marinated California Figs. Valleyfig.com

© Lorelle Del Matto 2022