Tryptophacts – Time to Talk Turkey3 min read
When did tryptophan become the cause of our post-meal slumber? I did a little Google Timeline search and found a citation back in the seventies, but it seems to really have picked up its mythical legs in the late 80s and 90s. Now, one can find tryptophan gift items. The tryptophan molecule t-shirt I first saw (do I have to admit this?) at ThinkGeek.com seems to have been discontinued, but Zazzle.com has come to the rescue in a big way. Their site features over 200 tryptophan-related items, some much better than others.
However, this post is not a celebration of tryptophan and our collective ability to nap in the middle of the week once every November. Rather it is time to talk turkey, to cull the fact from the myth. Sorry all you tryptofanboys out there, but the truth is a little easier to swallow than some dry, white meat or stuffing.
It seems that tryptophan is found in many foods. Yes, it is in turkey, but at levels that are similar to levels found in most meats. Wikipedia’s table shows that egg whites actually have the highest tryptophan content of any food: about four times the levels found in turkey. Even soybeans have more than twice what is found in turkey — bring on the tofurkey. Further research, found at NutritionData, actually turned up the Stellar sea lion as the real leader in tryptophan, although it is an endangered species and is not found on most dinner plates. I am troubled by the fact that Wikipedia’s Stellar sea lion entry failed to uncover their high level of tryptophan. It may be back to the Encyclopedia Britannica for me.
In any event, most sources come to the obvious, but hard-to-admit, conclusion when trying to place blame on Thanksgiving Day drowsiness. No, I am not talking about the lack of excitement found in the perennial Detroit Lions gridiron clashes. It is a combination of carbohydrates (read – mash potatoes and rolls) and alcohol. On the carbohydrate side, the science behind it does incorporate tryptophan, but it is not the cause; it is a complex sequence of interactions that starts with glucose and ends with serotonin and melatonin. On the alcohol side, from How Stuff Works, Craig Freudenrich, Ph.D. details the effects as one’s blood alcohol content (BAC) increases. Sleepiness begins with a BAC as low as 0.09 (or about three to four drinks).
As I recently discovered, and a great term to discuss over tomorrow’s meal, this is known as postprandial somnolence, or PPS “for those in the know.” Have a safe and healthy holiday weekend, and whatever you do, don’t drink (or text) and drive.