Gulp!

It is not easy to write diplomatically about sex and bowel functions, but Mary Roach does it.  She is a fearless science writer who manages to take taboo subjects and turn them into good books packed with information written in a style that is easily accessible without being condescending.

In Stiff: The Curious Life of Human Cadavers (Norton, 2004), she tells us just what happens to our earthly shell once we shuttle off this mortal coil.  Bonk:  The Curious Coupling of Science and Sex (Norton, 2009) takes us inside the human bedroom and into the sheets for some blushing details about how we make love.  She is also the author of Packing For Mars:  The Curious Science of Life in the Void (Norton, 2010), an exploration of human beings in space and all that it entails.  If you are sensing a pattern here, focus on the word “curious.”  Mary Roach is nothing but curious, and she takes us on a journey in each of her books with insight and humor, although at times she reaches a bit too far for the witty aside.

Her most recent book is Gulp: Adventures in the Alimentary Canal (Norton, 2013).  The alimentary canal is the anatomically correct name for the entire length of the human digestive tract, mouth to anus.  It is, in fact, one long superhighway.  So when you kiss your significant other, you’re getting the sweet end of 29 feet of intestines.

It is not too unpleasant to write about the mouth.  Roach breaks down (pun intended) the makeup of saliva and the way digestion begins with chewing what we stuff into our pie hole.  To a non-scientist, it might be surprising to learn that there are people out there who study the different kinds of saliva.  “Humans secrete two kinds of saliva,” Roach writes, “stimulated and unstimulated.”  We also learn that babies drool because they lack the teeth to keep back the flood.  The spittle also contains extra lipase, “an enzyme that breaks down fat,” since the little person is on an all-milk diet.  Fascinating.

Of course, it is the other end of the alimentary canal that could cause writing constipation.  How do you write about, well, you know?  Roach does not shy away from the unpleasant stuff.  Let’s just say, she covers everything you need to know about flatulence, or more than you want to know, for that matter.  We also get to hear about one more attribute Elvis Presley had: a megacolon.  And evidently, one can die from constipation.  There have been several cases of sudden death while straining to pass a megacolon’s worth of stuff.  And if you think fiber is key to good colon health, think again.  Roach blows the lid off of the whole probiotic and fiber diets as the passage (again with the pun) to pristine bowels and a healthier life.  She cites a study in the American Journal of Epidemiology in 2010 that found that “Frequent bowel movements were associated with an increased risk of rectal cancer in men, and constipation was associated with a decreased risk.”  The bacteria in probiotics are aerobic and thrive only in an oxygen-rich atmosphere.  It is the anaerobic kind that love to throw parties in the human colon.

The book ends with probably the most disgusting development in medicine since the leech:  the fecal transplant.  Yes, when one suffers from chronic bowel disease, a successful new treatment might be to insert some fecal material containing a healthy bacterial cultural from a donor into the ill person’s depleted gut.  Roach takes us through the process from donor to insertion.  It is not really all that unpleasant as described; it is more the thought that is troublesome.  And it is less painful, certainly, than donating bone marrow or a kidney.

I also read a second book by Mary Roach this early summer:  Spook: Science Tackles the Afterlife (Norton, 2005).  She takes a scientific approach to ghost hunting and other matters of the supernatural.  For those hoping for proof of actual dead people involved in things that go bump in the night, you will be disappointed.  Science simply cannot validate ghosts.  However, Roach did learn that electromagnetic energy can make us hallucinate and think we see ghosts, especially if one is right-hemispherically dominant.  “The theory holds that certain patterns of electromagnetic field activity—both the earth’s own natural kind and the man-made kind created by wiring and appliances and power lines—can render the brain more prone to hallucinations,” Roach writes.  “In particular, the sort that involve an invisible, sensed presence.”  She questions the scientist doing the research whether or not these perceptions are actual voices from the other side.  His answer is startling.  Because of the effect on the brain, they may be picking up “actual information that’s in the environment…particularly in places where people experience the same thing again and again.”

Physics tells us that there may be other dimensions sharing our environment, and possibly electromagnetic energy targeting our brains gets us a clearer signal from those dimensions.  On a purely scientific note, Roach finds little evidence to confirm the presence of the supernatural, however, such entities cannot be eliminated by science either.  What is valuable about this book is the clear-headed way she picks apart her subject.  She has, in all her books, the remarkable ability to make difficult science understood by those of us who are not scientists, and she does this with clarity and humor.  At times, she might be simplifying too much, but for a general reader, her books offer a gateway into much broader and deeper research if one is intrigued.  In other words, Mary Roach offers a place to start with science topics with broad appeal.  In addition, she tries very hard to keep the mood lighthearted and fun, even when the subject matter is taboo or distasteful.  At times, she reaches too far for the humor, although better to integrate some funny lines when dealing with dry science, or a dry bowel movement.

I have enjoyed Mary Roach’s writing for years, and once immersed in her books, it is hard to pull away.  She is definitely good vacation reading, and one leaves a book more enlightened and knowledgeable.  Quite possibly she has written the perfect bathroom reading in Gulp, however it is most decidedly not the book you want to be perusing while eating a meal.