Reviewed in the United States on June 14, 2013
I can't recommend this book highly enough. Roach truly is the funniest, best science writer I've ever had the pleasure to read. Her inquisitive mind doesn't always follow a linear path & the side tracks are illuminating.
"While a seaman might survive the suction and swallow, his arrival in a sperm whale's stomach would seem to present a new set of problems."*
*I challenge you to find a more innocuous sentence containing the words sperm, suction, swallow, and any homophone of seaman. And then call me up on the homophone and read it to me.
- Mary Roach in "Gulp: Adventures on the Alimentary Canal"
Jonah got swallowed by a big fish? The above quote is in the part of the book discussing that. The good news is that whales have a fore stomach with no digestive juices. The bad news is that it is like a gizzard on some birds & crushes the food into manageable sizes. Sharks will also swallow prey whole, but their stomachs do have digestive juices & they do digest living prey as three sea turtles found out to their detriment.
Yes, much of the book was about gross stuff, but it was seriously interesting. We're basically an evolved digestive system. The alimentary canal is the core of the man-beast. It creates our energy & all the rest of the body is simply a way to spread the wealth & get a return investment to feed it more efficiently. We rely on (live for?) our gut & the sales pitch we're subjected to daily is full of misinformation & outright lies.
You think I go too far? The first third of the book is devoted to what we eat & why. Smell & taste are not processed by the frontal lobes of our brain. Did you know that people who lose their sense of taste & smell can actually starve to death because they can't swallow? It's that important.
Our body's sensors can get screwed up & we can develop bad habits, but it's often good to give in to a craving. I never thought much of food restrictions & never subscribed to any fad diets, thankfully. I always try to eat a fairly balanced diet of what I want & apparently that's pretty much a good thing since everything is working well & I've been the same weight since I was 20. Maybe liver tastes yucky to me because I shouldn't eat it. Yeah, I'm going with that.
Why do some diets work for some people & not for others? Apparently, each gut is as unique as a fingerprint. By the amount & types of bacteria in it, your family could be traced since Momma seeds yours. What you digest & how is also covered to some extent. This isn't a dietary book, though. There are no clear cut answers to the individual, but there is a lot of overall knowledge.
I never knew how much misinformation was floating about. The chewing fad of the early 1900's was disproved a century or more (Roach gives dates, I just have a bad memory.) before it was suggested & even implemented in some cases by our government, basically at the behest of a well connected con man. But that's just one of many cases she discusses throughout the book. Many are still in play today.
The stomach is amazingly ductile, but people can blow it up. Interestingly enough, it's never happened to a competitive eater. There are several sections devoted to this wondrous organ & its abilities. Really interesting chapters devoted to comparing what it can digest & how fast it moves food along, too.
The small intestine gathers most of good stuff out of what we swallow and the colon gets a little more plus the water, but it does some important digestion of its own. I was a little disappointed that there wasn't anything about the gall bladder, but my wife's problems with that organ taught us that it isn't considered part of the digestive system, even though bile is very important in the process. Be warned. Your stomach doctor might scope you through both ends, but they don't do gall bladders at all. It's like the step child of the digestive system. They just tell you to take Maalox & ignore it after that.
She also explores the similarities & differences between our digestive system & that of herbivores a bit. I didn't know that rats & rabbits processed their food for many vitamins in their colon (B's & K). Process, but not absorb. Whoops! This is why they HAVE to eat their own poop. (Bunnies suddenly aren't nearly as cute, are they?) They're severely stunted if diapered. More illuminating are the comparisons between us, gorillas (vegetarians) & monkeys.
Probiotics? The overwhelming majority are just marketing. The bacteria you need most are anaerobic (can't live in an oxygen environment) so you won't find them in a yogurt cup nor will they survive the trip through the stomach. There is a way to restore them, but neither the insurance nor pharmaceutical companies are happy with it. You probably won't be either, unless you're suffering from severe colon problems & changing your own diapers a dozen times a day. Two words: Fecal Transplant. It often works, too.
There are a couple of chapters devoted to farts. Gross! Yeah, but figuring out what makes them stop smelling would sure be nice, wouldn't it? I've been in a couple of elevators that I barely made it out of with my lunch intact. So some people study them, even make synthetic farts. Eating charcoal doesn't help - it's absorbancy is used up way before it gets to the colon where the smelly gases are generated. So just how do they deodorize them? Well, Beano DOES help with beans, but they've worked out some other ways, too. Unfortunately, no one will read about them in normal magazine ads. Those publications say the yuck factor is too strong. You can find out about them in this book, though.
There's another quote in the book about the anus being a marvel of engineering beyond man's technical ability in that it is able to handle gas, liquids, & solids on command with aplomb. (Usually, hopefully!) So calling someone an a*hole is really talking them up!
This has gotten way too long, sorry. It's fascinating & I only touched a few of the high points. There's a lot of excellent knowledge here & only Roach's delicate touch could make it so readable, even at lunch time, about the only time I have to read during the spring.
I'd also like to tip my hat to Ed, Mary's husband. You're a lucky man, but you must have a great sense of humor & the hide of a rhino. Seriously, she explores whether or not he can kill her in the night with beer farts if she sleeps with her head under the covers! That's almost as bad as his trip to England in Bonk: The Curious Coupling of Science and Sex where he got to spoon with Mary while a doctor used a sonogram to see how things fit together during coitus. Ed, you're a better man than I!