IN 1979, A pair of Minneapolis researchers put Fletcherism to the test. They brought ten subjects to the local Veterans Administration hospital, and purchased some peanuts and jars of peanut butter. The subjects first ate a diet in which almost all the fat came from peanuts. The peanuts were then swapped out for the peanut butter—an aesthetically acceptable stand-in for excessively chewed peanuts. The subjects’ “digestion ash,” as Fletcher liked to call excrement, was then analyzed to see how much of the peanut fat was leaving the body unabsorbed.
“‘Nature will castigate those who don’t masticate’ may hold some truth,” concluded the paper, which appeared in the October 1980 issue of the New England Journal of Medicine. On the whole-peanut diet, the subjects excreted 18 percent of the fat they’d consumed. When they switched to peanut butter, only 7 percent escaped in their stool.
But peanuts are hardly representative of the average food. Everyone knows—via “visual observation of stool samples,” to use the New England Journal of Medicine’s way of saying “a glance before flushing”—that chunks of peanuts make their way through the alimentary canal undigested. Nuts are known for this. Peanuts (and corn kernels) are so uniquely and reliably hard to break down that they are used as “marker foods” in do-it-yourself tests of bowel transit time[32]—the time elapsed between consumption and dismissal. Peanuts are the food singled out for this trait by Martin Stocks, business development manager for the Model Gut, a computerized tabletop digestive tract[33] that can be hired out for absorption studies.
I had contacted Stocks to see if it might be possible to engage the Model Gut for a test of Fletcherism. It was, but would “likely run into the $10,000 to $20,000 range.” Stocks’s opinion was that with a few recalcitrant foods—here he singled out nuts and rare or raw meat—extensive mastication (chewing) might make a small difference in how much energy and nutrients are absorbed, but that it was “unlikely to have a dramatic effect on one’s overall nutritional intake.”
Stocks passed my e-mail along to Model Gut senior scientist Richard Faulks. Faulks was dismissive not only of extreme chewing, but also of the related fad for blenderizing to increase the accessibility of nutrients. It’s true saliva carries an enzyme that breaks down starch, but the pancreas makes this enzyme too. So any digestive slack caused by hasty chewing would be taken up in the small intestine. The human digestive tract has evolved to extract the maximum it can from the food ingested, Faulks said, and that is probably all it needs. “Nutritional science is dogged by the idea that if some is good, more is better,” he said, “and this has led to the belief that we should endeavor to extract as much as possible of whichever fashionable component is in vogue. This is to ignore evolutionary biology and the imperative of survival.” He pretty much ran Horace Fletcher through the Model Gut.
One thing to be said in favor of thorough chewing is that it slows an eater down. This is helpful if that particular eater is trying to shed some weight. By the time his brain registers that his stomach is full, the plodding thirty-two-chews-per-bite eater will have packed in far less food than the five-chews-per-bite wolfer. But there’s thorough and there’s Fletcher. Chewing each bite, say, a hundred times, Faulks said, could have the opposite effect. It would lengthen the meal so radically that the stomach could have time to empty the earliest mouthfuls into the small intestine, while the last mouthfuls are still on the table. Thereby making room for more. Fletcherizers’ meals could conceivably be so interminable that by the time they finally cleared their plate and set down their napkin, they’d already be feeling peckish again.
Not to mention, the morning’s half gone. “Who has time for this?” was the reaction of Jaime Aranda-Michel, a gastroenterologist with the Mayo Foundation, when I called to ask him about Fletcherizing. “You’re going to spend all day just having breakfast. You will lose your job!”
LONG BEFORE DIGESTION researchers had veterans’ stool and Model Guts to play with, they had Alexis St. Martin. In the early 1800s, St. Martin worked as a trapper for the American Fur Company in what is now Michigan. At age eighteen, he was accidently shot in the side. The wound healed as an open fistulated passage, the hole in his stomach fusing with the overlying holes in the muscles and skin. St. Martin’s surgeon, William Beaumont, recognized the value of the unusual aperture as a literal window into the actions of the human stomach and its mysterious juices, about which, up until that point, nothing much was known.
Experiment 1 began at noon on August 1, 1825. “I introduced through the perforation, into the stomach, the following articles of diet, suspended by a silk string:… a piece of high seasoned à la mode beef; a piece of raw salted fat pork; a piece of raw salted lean beef;… a piece of stale bread; and a bunch of raw sliced cabbage;… the lad continuing his usual employment about the house.”
On the very first day of his research career, Beaumont’s work dealt a bruising blow to Fletcherism[34]—seventy-five years before it was invented: “2 p.m. Found the cabbage, bread, pork, and boiled beef all cleanly digested and gone from the string.” No chewing necessary.[35] Only the raw beef remained intact.
Beaumont carried out more than a hundred experiments on St. Martin and eventually published a book on the work, securing his place in the history of medicine. Textbooks today still make reference to Beaumont, often with hyperbolic phrasing: “the father of American physiology,” “the patron saint of American physiology.” From the perspective of Alexis St. Martin, there was nothing saintly or fatherly about him.
5. Hard to Stomach
THE ACID RELATIONSHIP OF WILLIAM BEAUMONT AND ALEXIS ST. MARTIN
THREE FAMOUS ENGRAVINGS depict Alexis St. Martin in his youth. I’ve seen them many times, in biographies of his surgeon William Beaumont, in Beaumont’s own book, in journal articles about the pair. As detailed as the artworks are, you can’t tell what St. Martin looked like from examining them. All three woodcuts are of the lower portion of his left breast, and the famous hole. I could pick St. Martin’s nipple out of a lineup before I could his eyes. I suppose this makes sense; Beaumont was a researcher and St. Martin his subject—more a body than a man. But the two knew each other across a span of thirty years. They lived together on and off for a decade. Over all this time, did no fondness develop? What exactly was their relationship? Was St. Martin mistreated, or was digesting for science the cushiest job a hard laborer could hope for?
The two first met in June 1822, at a company store on Mackinac Island, part of a trading post owned by the American Fur Company. St. Martin was a French Canadian voyageur—an indentured trapper—hauling pelts by canoe and on foot through the woodsy landscape of the Michigan Territory. St. Martin retained little memory of the pair’s historic meeting, lying, as he was, barely conscious on the floor. Someone’s gun had discharged accidently, spraying a load of duck shot into St. Martin’s side, and Beaumont, the army surgeon assigned to the nearby garrison, had been called down to help.
32
The human digestive tract is like the Amtrak line from Seattle to Los Angeles: transit time is about thirty hours, and the scenery on the last leg is pretty monotonous.
33
“It can even vomit,” boasts its designer. No reply arrived in response to an e-mail asking whether and into what the Model Gut excretes.
34
More recently, the digestive action of a healthy adult male obliterated everything but 28 bones (out of 131) belonging to a segmented shrew swallowed without chewing. (Debunking Fletcher wasn’t the intent. The study served as a caution to archaeologists who draw conclusions about human and animal diets based on the skeletal remains of prey items.) The shrew, but not the person who ate it, was thanked in the acknowledgments, leading me to suspect that the paper’s lead author, Peter Stahl, had done the deed. He confirmed this, adding that it went down with the help of “a little bit of spaghetti sauce.”
35
The Beaumont findings were pointed out to Fletcher in a discussion that followed a lecture of his at a 1909 dental convention in Rochester, New York. “It made no practical difference whether the food was previously masticated very thoroughly, or whether the morsel… was introduced… in one solid chunk,” said an audience member. Before Fletcher could reply, two more doctors chimed with opinions on this and that. By the time Fletcher spoke again, two pages farther into the transcript, the mention of Beaumont was either forgotten or conveniently ignored. At any rate, Fletcher didn’t address it.