Can Turkey Make You Feel Sleepy?

Many of us find ourselves wanting to nap on Thanksgiving, and some suggest turkey could be the cause. So, does turkey make you drowsy, or is there another reason? Turkey contains a natural sedative, an amino acid called tryptophan.

What is Tryptophan?

Tryptophan is a vital amino acid that the body uses to produce melatonin, serotonin, and the B vitamin niacin. Melatonin regulates your sleep cycle, while serotonin is a neurotransmitter involved in sleep. So, consuming a lot of turkey might make your body produce more melatonin and serotonin, which could lead to feeling sleepy and wanting a nap.

This idea led many to start taking tryptophan supplements in the 1980s as a remedy for insomnia. However, in 1990, the U.S. Food and Drug Administration (FDA) banned tryptophan supplements due to an outbreak of eosinophilia-myalgia syndrome, a condition that causes muscle pain and even death.

The FDA blamed contaminated tryptophan supplements for the outbreak. However, it is now believed that the illness was caused by contaminants in the factory in Japan that manufactured the supplements, and they are once again available in the U.S. [source: Miller].

How Much Tryptophan Is in Turkey?

A pound (0.45 kilograms) of light meat turkey contains 410 milligrams of L-tryptophan, while a pound (0.45 kilograms) of dark meat contains 303 milligrams of L-tryptophan.

Nutritionists and experts suggest that the tryptophan in turkey likely won't stimulate the body to produce more serotonin because tryptophan works best when the stomach is empty. During Thanksgiving dinner, the tryptophan competes with other amino acids the body is trying to use, meaning only a portion of the tryptophan reaches the brain to help create serotonin.

Turkey isn't the only food rich in tryptophan. Other foods such as bananas, cheese, chicken, chocolate, milk, oats, and nuts also contain tryptophan.

Thanksgiving Dinner and Tryptophan

The traditional Thanksgiving feast is most likely the culprit behind that post-meal sluggishness. The meal tends to be rich, packed with carbs, ranging from mashed potatoes to bread, stuffing, and pie, all of which demand significant effort from your digestive system. On average, a Thanksgiving meal contains around 3,000 calories and 150 grams of fat [source: Snider]. Plus, if you have alcohol with your meal, its sedative effect will only amplify the tiredness.

So, don't blame the turkey for your holiday fatigue! It's more likely the result of overeating, drinking alcohol, and the early darkness of the season. If you feel the need for a nap after Thanksgiving dinner, don't worry — it's perfectly natural!