The Science of Sleepiness at Thanksgiving: It’s Not the Turkey!

Q. With Thanksgiving approaching, my friends and I want to know, is it true that eating turkey makes you sluggish?


turkey thanksgiving 300x277 The Science of Sleepiness at Thanksgiving: It’s Not the Turkey! Photo

Don’t blame the bird for sleepiness after the Thanksgiving meal.

A. Traditionally on Thanksgiving, it’s not just the turkey that gets stuffed! Many of us fill ourselves with turkey, sweet potato pie, cranberry sauce and a host of deserts, liberally washed down with cider, wine or our favorite beverages. Typically, after feeling so full that we can’t move, we collapse onto the couch where an overwhelming feeling of exhaustion washes over us.

Is it the Turkey?

Turkey has long been blamed for causing lethargy due to the L-Tryptophan within it. This is an essential amino acid or protein, which the body needs to manufacture a Vitamin B, niacin – important for digestion, nerves, skin integrity and serotonin. Serotonin is a brain chemical that contributes to a better mood and relaxation. Serotonin also makes the hormone melatonin, which induces sleep.

The thing is, despite popular rumor, turkey actually has less tryptophan than chicken or other poultry.

While turkey is a source of tryptophan, foods that are laden with tryptophan include:

  • Milk
  • Yogurt
  • Fish
  • Red meats
  • Eggs
  • Cheese
  • Sunflower and pumpkin seeds
  • Chickpeas
  • Peanuts
  • Bananas

Drowsiness following the Thanksgiving meal may actually be from the carbohydrates eaten alongside the turkey. It has been shown in several scientific studies that a meal filled with carbohydrates causes insulin release.

As the insulin pours into the system, excess sugar from the carbohydrates is deposited into your cells rapidly, leaving less in circulation. After an initial rise in blood sugar, the insulin can cause a crash with lower levels of blood sugar than before food consumption.

Hypoglycemia, a condition of low blood sugar, can cause fatigue, irritability, insomnia, sugar cravings, heart palpitations and light- headedness, until you eat again, restarting the cycle.

In addition, insulin rouses uptake of larger amino acids into the muscle, leaving a higher concentration of tryptophan in circulation. The tryptophan is converted into serotonin and further metabolized into melatonin by the pineal gland, in the brain, causing post-feast tiredness.

Through this indirect mechanism, the meal heavy in carbohydrates is actually the culprit in increasing the sleep-promoting melatonin.

“I’ve Been Drugged”

In clinical studies, tryptophan has demonstrated some promise in antidepressant therapy. The elevation of serotonin from the tryptophan may treat depression or elevate the mood and has been used as a dietary supplement in Europe for this.

So, having mood elevation and a feeling of being mellow while dealing with the stress of family get-togethers is actually not a bad side effect. Eat an extra helping of turkey instead of dessert.

Have a Happy and healthy Thanksgiving. (And bon appetite!)