Gulp: Adventures on the Alimentary Canal

Gulp: Adventures on the Alimentary Canal

Book Information

W.W.Norton April 2013
Science Curriculum

"Food, glorious food!

We're anxious to try it

Three banquets a day --

Our favorite diet!

-- from the musical Oliver


"Silletti hands me a plastic cup and sets a timer. We are moving on to unstimulated saliva. This is background saliva, the kind that's always flowing, though much more slowly. A minute passes. We turn away from each other and quietly spit in our cups.

"'Look at the difference compared to stimulated.' Silletti tilts her cup. 'You can't pour it easily. It's so viscous. Look!' She dips the end of a glass pipette into her sample and pulls it away. Filament is a nice word, Silletti's word, for the mucoid strand that trails behind.

"Relatively little is known about unstimulated saliva. Partly, Silletti says, because no one wants to work with it.

"'Because it's so gross?'

"'Because it's harder to collect. And you can't filtrate it. It clogs the filter, like hair in the drain. And you cannot be precise because it's so slimy.'

"'Right, it's gross.'

"Silletti tucks a strand of her glossy black hair behind her ear. 'It's difficult to work with.'

"Unstimulated saliva's trademark ropiness is due to mucins, long chains of amino acids repeating to form vast webs. Mucins are responsible for saliva's least endearing traits -- its viscosity, elasticity, stickiness. They are also responsible for some of its more heroic attributes. Unstimulated saliva forms a protective film that clings to the surfaces of the teeth. Proteins in this film bind to calcium and phosphate and serve to remineralize the enamel. Webs of mucins trap bacteria, which are then swallowed and destroyed by stomach acids. This is good, because there are a lot of bacteria in your mouth. Every time you eat something, every time you stick your finger in your mouth, you're delivering more."


It is now a decade since I immersed myself in Mary Roach's STIFF: THE CURIOUS LIVES OF HUMAN CADAVERS, whilst a member of YALSA's 2004 Best Books for Young Adults committee (which we, in due course, included on that year's selection list).

Mary Roach's nonfiction explorations keep getting even more funny and fascinating.


I am thinking that Roach's work and popularity must just build upon themselves: When you become well-known for writing incredibly funny, bizarre, and well-researched science books, I imagine that you are subsequently granted more time to complete the next project and can trade on your popularity to more easily gain access to top scientists and studies in progress that provide up-to-the-moment information. So, each time you tackle a new topic, you end up with a book that is even better than the ones before.


"'What was hard,' Leavitt said, 'was finding the judges.' Leavitt needed a pair of odor judges to take 'several sniffs' and rate the noxiousness -- from no odor to 'very offensive' -- of each of the sixteen people's flatal contributions.* "


" *It could be worse. In a study of malodorous dog flatulence carried out at the Waltham Center for Pet Nutrition in Leicestershire, England, the far end of the scale was 'unbearable odor.'"


The fact is that GULP is a gas. Mary Roach begins with an exploration of the functioning of the nose and mouth as she explores how we interact with our food from one end of our bodies to the other. Side-splittingly hysterical, gross, eye-opening, fascinating, disturbing, and unforgettable are all words that readily describe what it's like to experience these step-by-step alimentary adventures and the million side journeys on which we are led by Ms. Roach through her research into these yummy topics. I advise you to not try reading this book while anywhere that you have to be quiet -- you could conceivably choke to death trying to stifle the laughter.


At the same time, the breadth of research and quality of information delivered here is such that I've been repeatedly talking about this book to anyone who will listen and am gearing up to pitch it to any high school AP science student who crosses my path:


"Why is it, then, that stomachs don't digest themselves? Why do one's stomach juices handily digest haggis or tripe but not the very stomach that excretes them?

"It's something of a trick answer. In fact, stomachs can digest themselves. Gastric acid and pepsin digest the cells of the stomach's protective layer, or mucosa, quite effectively...A healthy adult has a new stomach lining every three days. (More clever stomach tricks: key components of gastric acid are secreted separately, lest they ravage the cells that manufacture them.)"


It is so intriguing to read about what our own bodies are doing every day -- in fact what they are doing at this very moment. Now every time someone spits, burps, or farts (or talks about spitting, burping, or farting), I am thinking about some of the crazy stuff I've picked up from this brilliant piece of nonfiction.  350 pages  978-0393081572  

Recommended by:  Richie Partington, MLIS, Instructor, San Jose State University California USA

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