The Science of Tryptophan

You’ve probably heard that tryptophan is responsible for that sleepiness you feel after your big Thanksgiving meal or found a list of other tryptophan rich foods when searching for natural ways of getting more zzz’s. Have you ever wondered about the science behind what is going on when you digest tryptophan and why these foods encourage sleep?

Herb Roasted Turkey

According to the National Sleep Foundation, tryptophan, an essential amino acid (protein), doesn’t work alone when it comes to encouraging drowsiness. It’s actually the combination of protein along with carbohydrate that has a sleepy effect on you (so it’s the turkey and the stuffing that makes you want to hit the couch on Thanksgiving). Ok, so just because protein and carbohydrate work together to create tryptophan, how does that boost restful sleep?

The answer lies tryptophan’s role in producing melatonin, a hormone that is “turned on” at night to regulate sleep. The road to producing melatonin begins with tryptophan synthesizing serotonin in the brain. While only a small percentage of digested tryptophan goes toward creating serotonin, it is a critical process that plays a significant role in creating restful sleep. While most of us think of serotonin as a hormone, it is actually a neurotransmitter, which is involved in many processes and plays a key role in our central nervous system. So we know that tryptophan synthesizes serotonin, but how does this lead to melatonin production?

The answer lies in the conversion of serotonin to melatonin, which occurs in the pineal gland in the brain. It may not surprise you that the enzymes involved in this process are actually influenced by light (ie turned on more in dark hours) so that the production of melatonin truly works toward maintaining a normal sleep cycle.

While the science here may be confusing for some, the bottom line message is this: tryptophan converts to serotonin, which then helps create melatonin, a hormone known for regulating sleep. It is interesting to note, that researchers have found that melatonin supplements aren’t as effective at promoting sleep as our own production of it. One reason for this may be that our bodies know how to create it at the right time in our personal sleep cycle to encourage sleep when we need it.

If you are seeking better sleep, maybe what you need are a few more evening dishes that combine tryptophan-rich dishes with just enough carbohydrate to bring on the zzz’s. Here are a few to start with: