Just so everyone knows, it’s not the tryptophan in turkey that makes us so tired after our Thanksgiving meal. So, what is it then?
We know that Tryptophan is an amino acid present in many foods. However, in no way does turkey have an unusually high concentration. In fact, many beans and even beef has more tryptophan than turkey. It is true that tryptophan can help put you to sleep only because it feeds a pathway that creates melatonin (the sleep hormone). Scientifically the conversion goes like this: 5 HTP converts to serotonin which converts to melatonin and that equals “lights out.” The problem is that amino acids are absorbed at different rates and tryptophan is very, very poorly absorbed. If there were a race with different amino acids trying to get through one door, tryptophan would be the slow runner who is also wearing lead shoes. So, in fact, not very much tryptophan at all is absorbed when taken with a meal.
The answer to the snooze after the fabulous dinner lies on the plate in front of us. That wonderful plate usually contains a mound of carbohydrate-rich foods (that converts to sugar) which lead to a surge in insulin levels. Our pancreas is not always adept at matching the release of insulin, to our sugar intake, especially when large quantities of sugar are ingested. Many times the insulin surge is much too large; far exceeding the amount our bodies actually need, causing a sharp drop in blood glucose (sometimes referred to as bonking). This is called “reactive hypoglycemia” and we are all susceptible. As we start to store all that carbohydrate induced sugar, along with the tryptophan are some other amino acids that also get stored. This can increase the relative concentration of tryptophan, and even when running slow in lead shoes the tryptophan can still win the race .
So it’s a complex combination of many factors, two of which we discussed here, that create the turkey snooze. Most biochemists would agree that while the tryptophan plays a role, the sugar rollercoaster that the carbohydrates puts us on is the major causative factor.
Now, while we would usually advise that you avoid all those simple sugars and the subsequent “snooze” on that celebratory day, enjoy the food, the fun, and the nap.