Why do so many people fall asleep on the couch in the hours following the classic Thanksgiving turkey meal? The common explanation is that turkey contains a chemical (L-tryptophan, or just tryptophan), and that chemical is what makes you sleepy.
Is it true? Does turkey make you sleepy? Let’s look at some facts.
What is L-tryptophan?
L-tryptophan is an amino acid. Amino acids are proteins, and proteins are called the building blocks of life. Some amino acids, like tryptophan, cannot be produced by our own bodies. We have to find them in foods. Tryptophan helps our bodies make serotonin, which is a brain chemical associated with positive moods like well-being and relaxation. Serotonin produces the hormone melatonin, which helps you have regular sleep and waking cycles. All these facts sure make it sound like turkey might induce sleep, but…
How much tryptophan does turkey have?
Turkey contains tryptophan — but so do other poultries (like chicken), cheeses, eggs, fish, and other meats. In fact, turkey contains less tryptophan per serving than chicken does. Lots of foods have much more. Americans eat a lot of chicken and fish, and nobody seems to blame sleepiness on chicken or fish. If the tryptophan in turkey could make us sleepy, we would see it happen with other foods rich in tryptophan.
Do you get a serotonin boost from Thanksgiving dinner?
You can. The best chance for a serotonin boost is from a small (about 30 grams) all-carbohydrate snack, like a banana. The carbs can “escort” the tryptophan into the brain in a way that tryptophan can’t all by itself. This allows the brain to produce more serotonin. Your body usually has lots of tryptophan anyway, since Americans usually eat more protein than they need. There are lots of carbs served with the traditional Thanksgiving dinner: for example, stuffing, cranberry sauce, and mashed potatoes. But most American dinners have plenty of carbs, so…
Why does Thanksgiving dinner seem to make us sleepy?
Maybe it does, but the culprit is probably not the turkey. It’s probably because:
- People overeat: Any big meal can trigger sleepiness, especially if it contains carbs and tryptophan.
- People are travel-weary: Visitors have made long drives, flights, etc.
- Stress: Spending time with some of our relatives may be difficult for us.
- Sleep deprivation: Hosts get up early to prepare meals and clean the home.
- Alcohol: Many people overindulge on the night before Thanksgiving and are hungover. (That’s your body’s way of telling you that alcohol is bad for you.) Or, they may have a few alcoholic drinks with Thanksgiving dinner, depressing the system.
So, you may feel like taking a nap after thanksgiving dinner. But don’t blame the poor turkey. Remember, it’s already had a bad day.