A turkey never voted for an early Christmas or a biochemical albatross

I always remember a Seinfeld episode where Jerry and George become addicted to playing with an antique toy collection belonging to Jerry's girlfriend, and use wine and turkey to drug her into naps. What's that thing in turkey that makes you sleepy, George and Jerry? Tryptophan!

So it hazards a chance that sometime after your family Thanksgiving meal, when the kids have long left the table and the Detroit Lions are embarrassing themselves in their lone annual national appearance, someone will look around at the clan, delirious from a giant meal and trot out an old trope as to why all the logy faces - that mischievous, impish molecule - tryptophan - has put us all to sleep, said to be found in titanic proportions in that marquis entree, the turkey.

Tryptophan myths and what really brings you down on Happy T - the technical term being post-prandial somnolence - have been running around the Thanksgiving table like chummy cousins for at least the last twenty five years. But indeed, there's little credence to the idea tryptophan is an ultimate torpor torpedo.

Tryptophan is one of those 20 essential molecules called amino acids that humans need to find in their diet as the body lacks sufficient metabolic machinery to effectively create them from other materials. Amino acids are the building blocks of peptides or more commonly, proteins of all styles which make up you and me and buffaloes, Venus flytraps and the H1N1 influenza virus. The amino acids are all like various types of construction material with their own individual character. Some make loops and some make bends, others are straight and others have side chains like branches of a tree, sticking out in various means to provide all sorts of flavor to your protein creation. Tryptophan also offers some other uses to living things, being a precursor of plant-growing hormones called auxins or the essential nutrient niacin, Vitamin B3. A variant of tryptophan is even used by the curious cone snail as a component of its venom, contryphan, a neurotoxin it can jab into prey with its harpoon-like tongue called a radula.


The seed of this myth likely comes from a series of experiments at Oxford University where people were asked to drink a special amino acid mixture and then have them participate in the Prisoner's Dilemma, a game based on mutual cooperation. As players were deprived of tryptophan in their drink, indeed, those players will significantly less likely to cooperate. So there does appear to be a biochemical underpinning to the myth. Tryptophan is the substrate, or starting material for the synthesis of serotonin and in turn, melatonin, neurotransmitters both of which have a hand in regulating our circadian rhythm and need for sleep. From here it's just an irrational but tempting leap to conclude that big delicious bird is going to put you down for a few hours as it jams your head full of sleepy chemicals.

But that's not the end of the story.

While you can find tryptophan in turkey, there's no more per gram of protein than you'd find in chicken or cod or even beef. Indeed, there are a multitude of foods where tryptophan racks up in abundance including milk, eggs, soybeans and sesame seeds. You'd soak your system in tryptophan at about double the rate if you drank milk at equal levels you ate turkey. To go even further, tryptophan is the least abundant amino acid commonly found in natural protein, so as you load all that turkey into our guts, tryptophan has to get into the brain by the same blood-brain barrier gateways as all the other, far more abundant proteins. The stunning fact is your tryptophan levels in your brain (and thus, able to sing its psychotropic lullaby) will actually decrease with a meat-rich Thanksgiving meal of any stripe.

So chances are good that not only are the tryptophan levels in turkey insufficient to trigger a sleepy state in their best cases, they likely never get anywhere near a location of effect due to the giant protein meal actually depleting tryptophan levels as the large quantity aminos bull their way into the brain.

A better culprit of that bloaty corpse feeling? Those dreaded carbs.

It's a well-established fact in multiple animal models and human experiments that ingesting large volumes of carbohydrates provokes the release of insulin into the bloodstream. Insulin promotes the absorption of of branched amino acids, specifically large neutral branched chain amino acids into the muscle, but not tryptophan. This leaves tryptophan in the blood without competition as we saw earlier to get through that blood-brain barrier gateway. Once in the brain, then the raphe nuclei - the serotonin factories of the brain suddenly get a big shipment of tryptophan, convert it into serotonin and then to melatonin, the master sleep neurohormone,in the pineal gland, and turn the lights out. While tryptophan is a player in this model, it is those helpings of potatoes, stuffing, cranberry sauce and pie that put you down on the couch until those Turducken drumsticks are handed out to whomever whipped the Lions that day.

Tryptophan was actually marketed in the late 1980's as a diet supplement, boasted as a cure-all for depression, seasonal affective disorder, hypertension, obesity and even obsessive-compulsive disorder. A contaminated batch of L-tryptophan that led to the disability of hundreds and the deaths of 37 people, triggering a ban from the FDA in 1991. After the dust had settled and the contamination well-characterized, the FDA scaled back the ban in 2001 but still expressed skepticism:

"Based on the scientific evidence that is available at the present time, we cannot determine with certainty that the occurrence of EMS in susceptible persons consuming L-tryptophan supplements derives from the content of L-tryptophan, an impurity contained in the L-tryptophan, or a combination of the two in association with other, as yet unknown, external factors" Link

So enjoy that Happy T this year, take time to listen to grandma, take the Lions lightly, and have fun. But whatever you do, when you begin to feel catatonic, don't blame the tryptophan.

Maybe Jerry's girlfriend is just a lightweight drinker, afterall.

Playing with food never felt so artistic.

Enjoy here the bizarre and outright wild stylings of the Vienna Vegetable Orchestra, a group that generates its music exclusively from specialized produce they pick up from the grocer the day of the show.

The instruments require occasional lubrication during the performances, as the hot lights of a stage performance will begin to dry the raw plants, and that can apparently change the sound various carrot recorders and cucumberophones make, so they much dip them in water between pieces and sets.

The best part? They make a soup out of the instruments after the show and share with the audience.

A bucket of coke and a better built house: Fat America

A fantastic new book out, the Fattening of America attempts to get a real headlock on the hard questions as to why and how Americans have become so alarmingly obese. This is the first book I've read that takes a moment to ask a question most books gloss right over: Is a big Fat America a bad thing?

In the book, Eric Finkelstein, a health economist argues that our economy, with its massive increase in productivity through technology, has predisposed us to gaining weight. Our jobs have become more and more sedentary and new medical technology has overall lowered the risk of carrying a few extra or a few dozen extra pounds. The power saw and mechanical lifts have preserved the backs and knees of our construction workforce, but it also allowed them to get chubbed and diabetic. At the same time, our accelerated productivity has made things cheaper and more accessible to the bulk (no pun intended) of the population.

This book also intersects with an intriguing study out this week about how living longer is more expensive than being fat. For many years people have laid into the argument that being obese, and as such being more vulnerable to a host of metabolic diseases is a drain on the health care system. Indeed it seems a healthy individual with a longer life span will have a greater financial impact on government run and private health care than any group of obese individuals could do so.

Clearly in the end there's a lot of non-salient factors such as one's happiness, the impact of obesity on relatives and discrimination and social perception of obesity that aren't well covered here, but this book is truly the first in its field to crack open a lot of stronghold notions that have since gone unchallenged.

All things Patricky

Even on St. Patrick's Day, we here at the Ripsaw find you the best green boards to cut up for science digest.

The NY Times ran an article last week suggesting the various sects on the British Isles have a lot more in common than anyone wants to believe:

In all, about three-quarters of the ancestors of today’s British and Irish populations arrived between 15,000 and 7,500 years ago, when rising sea levels split Britain and Ireland from the Continent and from each other, Dr. Oppenheimer calculates in a new book, “The Origins of the British: A Genetic Detective Story” (Carroll & Graf, 2006).

As I've said before, Science tells us the truth, not what we want to be true! This particular scientist claims both Irish and English roots, so apparently it's not much of a distinction!

Everyone's familiar with the holiday's iconic plant, the Shamrock or Oxalis acetosella as we say in the scientific world. It's commonly mistaken for a clover, but did you know that the Shamrock is so different it's in a completely different taxonomic family? Talk about mistaken identity! A shamrock's three (or mutant four!) petals actually fold up at night or in harsh weather so as to conserve water from a reaction called transpiration. Also, they make a great prop for talking about your shape-shifting god.

Enjoy your beer! For those of you who thought serving beer in opaque kegs or colored glass was a pure aesthetic choice, think again! This is actually a protective measure, because indeed, beer can skunk when struck by light. This particular source cites UV light as the culprit, but I have read conflicting reports where longer wavelength blue light is the sulfur compound-forming culprit. In either event, treat your beer like it was a cool person. Make sure it has some shades on.


At the Ripsaw we don't put a lot of stock in luck, aside from it being a clever sorting of past events into artificial constructs, but hey, that's a human behavior. Want to avoid such luck-poor conditions? Avoid seeing red, says one study. Green? Now there's a color you can hitch your wagon to.

Getting the pure stuff

Happy New Year!

Enjoy a quick and fun article on the science of saffron. A most expensive spice, despite how much you pay for cardamom at the supermarket. Apparently one can cut one's stash with turmeric, most likely to turn a little extra profit. If you have some coffee filters and bleach, though, you can out these charlatans!

On a quick aside, I rarely see such wonderfully water soluble molecules in my line of work. Most prosecuted small molecules these days are terribly hydrophobic.

Food goes in, poo comes out.

Check out the Cloaca machines. An amazing setup of metal and plastic to mimic what evolution gave us millions of years ago. Part art, part engineering, this kind of device has a beauty of its own. From there, as pointed out by Jonah at The Frontal Cortex we see scientists taking the idea one step further for application research. Sounds like it will contribute to all sorts of medicinal research down the pipe, pun intended.

I'd love to fill it with a bunch of cheeseburgers and see if it gets all queasy.

Diablo Flavor

From Molecule of the Day:

The Devil's Flavor Wheel.


Not sure what the differences between 'farty', 'fecal' and 'eggy' are, but you get the idea.

How would you like someone to poison you?

In the tail episodes of my beloved Arrested Development it is revealed George Bluth had a penchant for sending poison muffins to his enemies, but just the first two, the other twenty-three were copycats. But it tickles my fondness for the best comedy ever when I stumbled upon this article in Nature. Does some folks' disdain for vegetables like cauliflower, brussel sprouts and others that contain the molecule phenylthiocarbamide, a compound that plugs into the TAS2R receptor in the taste buds. Molecule of the Day has some neat commentary on these embittering substances.

Discriminating poison is a vital part of the taste sense, if not its most essential. Wild almonds contain a high amound of toxin yet it was important for early adopters to roast the nuts to remove the threats such as prussic acid, better known as cyanide, a tasteless, odorless and potent poison.

Still, both green vegetables and nuts provide easily available sources of all sorts of vital nutrients, and one would be hard-pressed to turn these down or hand them over to competitors.