The Myth of Tryptophan

The Myth of Tryptophan Turkey Making You Tired

The Thanksgiving traditions are certainly odd when you examine them with a critical eye. It is a holiday in which we poorly re-enact a romanticized feast that symbolizes a failed treaty between two peoples. However, that is something most people in America often overlook in favor of just having an excuse to pig out. So, we celebrate via parades, long cooking times, and watching football. But what inevitably happens at the end of the day is everyone groaning and holding their bellies. Then everyone will want to sleep it off. Immediately, someone, whether it is that know it all uncle or parent who read one too many urban legends on the internet, declares “Its all because of tryptophan. That is what is making us sleepy!”

Not only is this a terrible misconception, but it is one that refuses to die every year. So, in the name of spreading accurate nutrition information and making Thanksgiving a little less miserable, we are going to address the whole tryptophan rumor once and for all. tryptophan, turkey

Tryptophan Is an Essential Nutrient

First, we need to address what tryptophan even is. According to Medline Plus, “Tryptophan is an amino acid people need for normal growth in infants and for nitrogen balance in adults. It is an essential amino acid. This means your body cannot produce it, so you must get it from your diet.”

So far, tryptophan is something that we need for nutritional balance. But what does it do? “The body uses tryptophan to help make niacin, melatonin, and serotonin. Serotonin is thought to produce healthy sleep and a stable mood.”

The previous statement could be what causes people to arrive at the misconception in the first place.  However, while they are related to the production of serotonin, their main contribution is towards the creation of niacin. Without niacin, our bodies would not be able to balance out their own cholesterol levels.

Not only that but we eat it every day. Way more often than we think we do.

Tryptophan is in Everyday Foodstryptophan

You see, because we need niacin in our daily diet, we get it from foods. Usually, tryptophan is in foods that have protein in it. So, if you ever eat eggs, cheese, chicken, nuts, fish, and tofu, then congratulations, you are eating tryptophan.  In fact, some of these things, like chicken, have even higher levels of tryptophan overall.

So, unless you are falling asleep left and right after eating lunch or dinner, then you are probably not getting drowsy from this amino acid.

However, it still does have a link to sleep regulation, but in an entirely different way.

How Tryptophan Works

According to, “Eating tryptophan doesn’t immediately impact serotonin levels. Tryptophan is just one of many different amino acids that are in foods like turkey. And all of those amino acids compete to get transported to the brain. Tryptophan is one of the least represented amino acids in those foods, which means that it gets shoved out of the way by the others.

That’s where this last piece to the puzzle comes in. There’s one thing that allows tryptophan to easily enter the brain: eating carbohydrates. Carbohydrates cause your body to release insulin, which removes all amino acids—except tryptophan—from your blood. That means that tryptophan has no competition and can enter the brain easily, boosting serotonin levels. So eating a snack that’s all carbohydrates will react with stored tryptophan in your body and give you a much bigger increase of serotonin. You can actually use this to your advantage by eating a light carbohydrate-centric snack before bedtime.”

So, it is part of what makes you fall asleep but needs carbohydrates to activate at all. This just leaves one question, “What makes you sleepy at the Thanksgiving Feast?”


What makes you sleepy at Thanksgiving is more times than not is a combination of a few things. According to, “However, turkey doesn’t contain a high level of tryptophan when compared to many other common foods. Post-Thanksgiving dinner sleepiness is more likely related to other factors, such as the volume of food or the quantity of alcohol or simple carbohydrates consumed.”

So, when you start to feel a little bit sleepy around this holiday season, don’t blame the turkey. Instead, just look at it as another terrifying Thanksgiving tradition that did not age well.

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