What is Tryptophan & Why You Need It

If you were a fan of Seinfeld you'll remember the Thanksgiving episode. Jerry starts dating a new girl that has an awesome toy collection. And since this happens to be right around the time of Thanksgiving, Jerry and the gang decide they will 'drug' his new girlfriend by feeding her a turkey dinner rich in tryptophan which is believed to induce sleepiness. Once they manage to induce a turkey coma in this poor girl can Jerry et al break out all the toys and play.

[caption id="attachment_4743" align="aligncenter" width="300"] What's the stuff in turkey that makes you sleepy? Tryptophan!


So what exactly is tryptophan? Well it's an essential amino acid meaning our bodies cannot make it and it's essential that we get in our diets. And just to back up a bit, amino acids are the building blocks of proteins. When we have a particular collection of amino acids, arranged is a very specific order and give this collection of amino acids a 3D shape we have a protein. I usually like to coach and teach with analogies so here's one for amino acids.

If we had a bead necklace that was balled up and folded into a specific shape that would represent the protein. All of the beads on the string represent the amino acids. If certain amino are missing, it's not the same protein. If the order of the amino acids i.e. the order of the beds on the string, changes then it's not the same protein. And if the shape of the balled up necklace changes, it's not the same protein.

But enough about protein chemistry, what does tryptophan do and why does that matter? Well tryptophan is a pre-cursor of a number of other important metabolites including: hormones such as serotonin which then leads to melatonin and vitamins such niacin (B3). If our tryptophan levels are low, we're going to have corresponding low levels of these hormones and vitamin.

So how can we ensure we have adequate tryptophan in the diet? Well it's going to be a component of most protein-rich foods. So you get it from meat, turkey, dairy, fish, eggs and some seeds. And contrary to what've heard turkey is no higher in tryptophan than other poultry such as chicken and is comparable to beef. Vegans and vegetarians can get tryptophan from spinach, seaweed, soy, sesame seeds and tofu. But while it is possible to get tryptophan from these non-meat sources, it is much more difficult.

The last thing to mention is that while you can increase your consumption of protein-rich foods, these efforts could all be for naught if combined with a low carbohydrate diet. Tryptophan is able to cross a specific boundary in the blood brain barrier (BBB). When carbohydrates are in short supply we will have difficulty moving tryptophan across the BBB for the production of serotonin and melatonin. When we consider the role these hormones play with respect to happiness, well-being and sleep, we can quickly see how a low carbohydrate diet may leave us sad, irritable and tired.

And we all know those low carb individuals in our lives, don't we hahaha :)

Anyways, the take home message is that we need to eat tryptophan. It is important as our bodies cannot make it and it is most abundant in protein-rich foods. Make sure your carbohydrate intake doesn't drop too low and you will reap all the rewards of this amino acid.

Oh yeah...I almost forgot. It's not tryptophan that makes us sleepy. In the case of the Seinfeld episode it was a case of a high-caloric meal, heavy in carbohydrates and fats. This draws all the blood to the gastro-intestinal track and away from the extremities. We then feel sluggish, don't want to move and just want to have a nap.