The Paradise of Cheeseburger Ignorance
“Should I be eating iron-fortified cereal?” “How about bread crammed with an extra dose of fiber?” “And if I pop a few Centrum Silvers every morning will I be as agile as the geriatric couple I saw on the moving picture box?” These are the questions that modern eaters face every time they visit the supermarket. But I’ve got a better question: Why can’t the scientists keep their grubby hands off my food?
In Michael Pollan's book The Omnivore's Dilemma, he analyzes the industrial food chain to death (no pun intended), tracing every atom of carbon we eat back through the animal kingdom, the corn on which the animals feed, the petroleum-born fertilizer on which the plants feed, and all the way back to the initial photon of sunlight that initially provides every calorie of energy consumed on this earth by both plants and animals. A major focus of Pollan's omnivorous rant is the nutritional irony of the modern approach to food, the fact that we've spent all this effort processing and refining foods down to easily mass-marketed and reproducible products. By doing so, we’ve essentially stripped away any natural nutritional benefit, so much so that we now must artificially fortify our foods with nutrients that were already present in the first place. Take for example the ample vitamins and minerals (vitamin E, various B vitamins, magnesium, iron, fiber) present in the bran and germ portions of a whole wheat grain, both of which are removed when wheat is refined. Now count the number of breakfast cereals who've begun artificially adding back lost nutrients and painting their boxes with exclamations like "A great source of fiber," and "Clinically proven to help reduce cholesterol." Well, maybe there wouldn't be so much cholesterol to reduce if food scientists hadn't removed all the good shit in the first place!
So while I'd like to thank Mr. Pollan for writing one the of most interesting and enlightening books I've read in years, I'm now plagued with a compulsive, deconstructionist interest in cuisine that sneaks up on me every time I try and enjoy a meal. I find myself incessantly analyzing nutrition labels, racking my dwindling remembrance of General Chemistry in search of an origin for something called "Polydimethylsiloxane.” Is it a refined corn byproduct? A completely synthetic polymer perhaps? And why must fast-food establishments put it in our food? (A quick Google search reveals it to be a silicon-based organic polymer used as an anti-foaming agent in processed foods to prevent gas leakage). While this approach has helped feed my academic curiosities to no end, in a cultural sense I find this intersection between food and science fundamentally unappetizing. When I sit down to a meal the last thing I want to think about is how much fiber I'm ingesting or how much cholesterol is building up along my arterial walls. I just want to fulfill my biological duty and eat food that tastes good and provides me with enough sustenance to survive until the next meal.
But in today’s world, this sort of utilitarian approach to food doesn’t seem to work. Which is precisely why I'm now feeling a bit nauseous as I sit munching this cheeseburger, wondering how many salivating mad food-scientists have poked, prodded and analyzed similar specimens in hopes of eliminating our blissful cultural disconnect from what we eat. Pollan’s got me hooked. I now find myself searching for my every meal in PubMed, the online, virtual warehouse of medical and scientific journals, trying to obtain as much of a scientific perspective on my food as possible.
My "Cheeseburger" search returns 11 entries. The most recent comes to us from the Pediatrics Department at SUNY Buffalo and was published in the journal Appetite, whose self-proclaimed research interests include the "Neuroscience of feeding and drinking" and the "Zoology of foraging." The study investigated the process of salivation as it correlates with motivated responses to food in children, a rather demeaning endeavor if you ask me. Basically, the researchers demonstrated that patterns of habituation, or the gradual decrease in response to a stimulus over time, are nearly identical for both salivation and a child's motivated food response. Salivation was measured by stuffing cotton balls into the children’s mouths and then weighing them, while motivated responses were assessed using a computer puzzle game in which a better score equated with more burger. The study found that when continually presented with a Wendy’s cheeseburger on a paper plate, a child's saliva production decreases with each subsequent patty at the same rate as his/her excitement and reaction toward the burger. When the habituated child is then presented with a sac of greasy French fries, both responses return to baseline.
The authors tentatively conclude that this finding could be due to the fact that the motivation to obtain food – encompassing both salivation and food response - is controlled in part by pathways in the brain involving the neurotransmitter dopamine, thus explaining why the responses occur together. However, I support the other theory posited in the paper, that the findings in no way suggest a common neurological pathway, as habituation is a common property of the nervous system and occurs in numerous responses, whether controlled by the same pathway or not. Since scientists have already known for quite a while that both salivation and motivational responses habituate to redundant stimuli over time, we've really learned nothing here. Furthermore, if you'll allow me another gripe, I must take issue with the researcher's menu selection. As a former Buffalonian, I can't for the life of me figure why this group of upstaters would express such disrespect for their regional fare and not present these hungry youngsters with a piping hot plate of Anchor Bar Buffalo wings.
The saliva keeps on flowing all the way down the list. In addition to the aforementioned cheeseburger study, there are three additional papers exploring the effects of cheeseburgers on salivation response. The first is simply the preceding paper to the one described above, also conducted at SUNY Buffalo and also published in Appetite, only this time using a Burger King cheeseburger. The next concludes that even after satiety develops, significant recovery of salivation and hedonic (pleasure and reward sensation) responses can be achieved by presenting a new food. To reach this conclusion, scientists alternated between pizza and cheeseburger courses. Lastly, a group out of the University of Manitoba measured salivary responses to a variety of foods, one of which was cheeseburgers. Sadly, the burger lost out to the number one saliva-inducer, rice, which presumably is the more acidic food and thus requires more spit to neutralize the mouth’s pH.
The handful of other studies uncovered in my search included a Lancet article on the so-called “Cheeseburger Bill,” the 2004 legislation passed by the House of Representatives prohibiting law-suits against fast-food makers for making our nation’s children obese. There was also a paper on US foreign aid policy which had something to do with sending cheeseburgers to Cairo and another on how chewing gum increases stomach secretions. But again, the bulk of the cheeseburger literature out there is salivary in nature.
So it seems that researchers have caught on to the scientific potential of this classic American dietary staple and have learned to exploit it for its secretion-inducing qualities. But I find no disgust in using a burger to assess human physiology and behavior; it's only food analysis at the molecular level that ruins my appetite. And surprisingly, there were only two studies in my PubMed search investigating the fundamental components of a cheeseburger. One concluding that increased intake of saturated fat elevates the risk of hyperemesis gravidarum - or extreme, persistent nausea and vomiting during pregnancy – and another study out of Poland reporting that certain fast-food products (burgers included) are adequate sources of iron, magnesium and calcium. But I'm neither a woman, nor Polish, so I feel as though there's a safe distance between myself and this molecular burg-ology, which leaves me gnawing on the final bites of this cheeseburger with a settled stomach and just as much ferocity as before my PubMed investigation. I actually think I'm starting to salivate.
References
Nelson R. "Cheeseburger Bill" protects food industry. Lancet. 2004;363(9413):954.
Potts M. Cairo dreams shattered. Lancet. 1996;348(9033):976.
PubMeditation
PubMed is the search engine of choice for most scientists and doctors, and is the reason why science libraries are usually empty these days. With archives of abstracts that go back decades and links to full journal article PDF files, PubMed is the gateway to science history, the tool for inflating your reference list, or making the painful discovery that your experiment has already been done. For this recurring column, we exploit its power for fun and mischief.