Author(s): Mary Roach
ISBN Number: 978-0393081572
APA Style Citation
Roach, M. (2013). Gulp: Adventures on the alimentary canal. New York: W.W. Norton & Company
Mary Roach in her usual amusing style approaches the topic of digestion from beginning to end. She starts by explaining the strong interaction between smell and taste. She meets with Sue Langstaff, an olfactory expert who can break down the smells of anything from beer to wine to olive oil. Roach herself however does not fare so well even after training as she attempts to rate different olive oils, but acknowledges the connection between smell and taste. Visiting a Dutch lab, the book discusses how saliva inside of the body is viewed as normal to digestion, but outside of the body is considered vile and disgusting. The study of saliva leads to a discussion of digestive enzymes. In Pavlovian type studies, researchers measure the amount of saliva generated which is then caught by what is known as the “Lashley cup”.
Roach explains that most people eat only about 30 different foods and that cultural traditions regarding what we eat are passed down from parents to children. However, if people experienced a wider variety of foods over an extended period, they came to enjoy novel foods more and more (mere exposure effect). Roach quotes Kurt Lewin, “People eat what they eat, rather than what they like”. She describes situations such as poverty, war, or simple scarcity that caused people to try different foods such as seafood guano (manure). Another curious digestive, but not time saving technique is that of 'Fletcherism' in which an individual chews each bit of their food until it liquefies. Horace Fletcher proposed that a man could get by on two-thirds of their required caloric intake by using this system. Other researchers have found little evidence to substantiate this technique and the act of continual chewing turns out to be rather irritating to both watch and conduct.
The story of Alexis St. Martin recounts the historic study of digestion in which after St. Martin is shot in the stomach his surgeon William Beaumont leaves a window in which to view St. Martin’s digestion. All form of trials are described, including one in which Beaumont hangs a piece of meat from a string to determine how long the stomach would take to decompose the meat. In another case of digestive oddity, Tom Little an Irish laborer is described. Mr. Little as a child had eaten hot soup that fused the sides of his esophagus together. In order to actually enjoy his meals, he placed some food into his mouth, spat it out and then placed the remainder into the opening surgeons had made in his stomach, proving that taste not just nourishment is a vital part of enjoying one’s meals.
Roach cites instances of individual’s eating ridiculous amounts of food such as Ben Monson who ate sixty-five Mexican tortillas in one sitting. Competitive eaters it turns out practice ignoring their gag reflex to eat more food that thought possible and stretch their stomachs during their “training” binges. Most commonly these eating binges involve drinking copious amounts of water.
As Roach nears the end of the digestive process, she addresses the question of the capacity of one’s rectum. She interviews doctors who have studied the capacity of what the typical individual can hold based on work with inflated balloons. In a chapter entitled “Up Theirs: The Alimentary Canal as a Criminal Accomplice," Roach visits a prison to find that the doctor’s ideas regarding this capacity have been far exceeded by prisoners who have smuggled goods into prison. While these “goods” are usually drugs and cigarettes, she features one individual known as “Office Max” who in a single attempt to smuggle goods into the prison brought in two boxes of staples, a pencil sharpener, sharpener blades and three jumbo binder rings before being caught. Like the competitive eaters, these individuals train to be able to hold as much as possible in one trip, resisting the urge to release the goods. The journey from start to finish is a strange one, but Roach keeps it entertaining throughout. If you have not read anything by Mary Roach be sure to also check out her classic books including Bonk (a scientific study of sex research) and Stiff (a summary of cadaver’s contributions to science).
Other Related Resources
Website for the book Gulp
Quiz on Gulp
Interview with the author of Gulp
Psychological Figures and Concepts
Alexis St. Martin
Mere exposure effect