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Tryptophan & Wang Leather

By Staff | Nov 17, 2011

While making notes about Thanksgiving and what might be important about that feast day of all feast days, I thought about the family’s desire to take a nap after dinner. That thought turned to tryptophan. Immediately, I had doubts about how to spell the word so I went to Wikipedia.

Tryptophan (IUPAC-IUBMB abbreviation: Trp or W; IUPAC abbreviation: L-Trp or D-Trp; sold for medical use as Tryptan)

So what does that have to do with turkey dinner?

After getting past the biosynthesis and industral production and a whole lot of chemical diagrams, I happened on this information:

“One belief is that heavy consumption of turkey meat (as for example in a Thanksgiving or Christmas feast) results in drowsiness, which has been attributed to high levels of tryptophan contained in turkey. However, while turkey does contain high levels of tryptophan, the amount is comparable to that contained in most other meats.

“Furthermore, post-meal drowsiness on Thanksgiving may have more to do with what else is consumed along with the turkey and, in particular, carbohydrates. It has been demonstrated in both animal models and humans that ingestion of a meal rich in carbohydrates triggers release of insulin. Insulin in turn stimulates the uptake of large neutral branched-chain amino acids (BCAA), but not tryptophan (an aromatic amino acid) into muscle, increasing the ratio of tryptophan to BCAA in the blood stream. The resulting increased ratio of tryptophan to BCAA in the blood reduces competition at the large neutral amino acid transporter (which transports both BCAA and aromatic amino acids), resulting in the uptake of tryptophan across the blood-brain barrier into the cerebrospinal fluid (CSF). Once in the CSF, tryptophan is converted into serotonin in the raphe nuclei by the normal enzymatic pathway. The resultant serotonin is further metabolised into melatonin by the pineal gland. Hence, this data suggest that ‘feast-induced drowsiness’ – and, in particular, the common post-Christmas and North American post-Thanksgiving dinner drowsiness – may be the result of a heavy meal rich in carbohydrates, which, via an indirect mechanism, increases the production of sleep-promoting melatonin in the brain.”

Now isn’t that more than you ever wanted to know.

Now turn to: Turkey meat and drowsiness — See also: Postprandial somnolence/Turkey and tryptophan

“Despite popular belief that turkey has a particularly high amount of tryptophan, the amount of tryptophan in turkey is typical of most poultry. Tryptophan is a routine constituent of most protein-based foods or dietary proteins. It is particularly plentiful in chocolate, oats, dried dates, milk, yogurt, cottage cheese, red meat, eggs, fish, poultry, sesame, chickpeas, sunflower seeds, pumpkin seeds, corn, spirulina, and peanuts.”

Here I was just going to make sure tryptophan was spelled correctly and we learned a whole lot more.

At Thanksgiving I am especially thankful for turkeys that come all packaged up. Wouldn’t it be a beast to have to go out and shoot your own turkey? It could take days!

My mother used to say that the meat on wild turkeys is “tougher than wang leather.” Now what exactly does that mean?

In the dictionary, “whang” is described as rawhide. If you consult “Ask Jeeves” online, it refers to “wang” leather being used as early as the turn of the century to describe resilience. I question whether Wang leather has much to do with Vera Wang, unless, of course, some of her designs incorporate leather.

With all this new-found knowledge, you are sure to appreciate your Thanksgiving meal even more.