Donaldson didn’t rest his case there. He withdrew small amounts of blood from his surgically constipated charges, once at the end of fifty-five hours, again at seventy-two hours, and finally at ninety-six hours. This he injected into the bloodstream of two normal, unconstipated dogs,* to see whether symptoms suggestive of “fecal poisoning” would develop. They did not.
Donaldson contended that the symptoms people and doctors were so quick to blame on autointoxication were in fact caused by the simple mechanics of constipation: rectal distention and irritation. To test the theory, he packed four men with turd-sized wads of cotton. After three hours, the men began to exhibit the sorts of symptoms commonly blamed on autointoxication. The moment the wads were removed, relief ensued. If fecal blood poisoning had been the culprit, relief would have taken far longer. It takes several hours for the liver and kidneys to clear chemicals from the system. The reek of asparagus pee, Walter Alvarez pointed out, though not in those exact words, doesn’t abate the moment you set down your fork. It lingers through the following morning. The very swiftness with which the enema brings relief itself refutes the premise of autointoxication.
In the incomparable phrasings of gastroenterologist Mike Jones, “Everybody who’s bound up feels a whole lot better after a big dump. From where I sit, you don’t need to invoke anything else.”
THE ALTERNATIVE APPROACH to ridding the body of “faeculent poisons” was to eat so much fiber that digesta sped through the colon too quickly to generate them. Insoluble dietary fiber, or roughage, is the indigestible, nonfermentable parts of plants—internal yard trimmings that the gut cannot break down. This fiber sponges up water, contributing dramatically to fecal “bulk.” The bulkier the trash, the sooner you need to empty the bin.
John Harvey Kellogg was the archbishop of roughage. The healthy colon, he maintained, empties itself three or four times a day. This was “Nature’s Plan.” As evidence, he cited the estimable bowel frequency of “wild animals, wild men, . . . infants and idiots.” Kellogg’s sources included the staff at “well-managed idiot asylums” and ape keepers at the London Zoo. Kellogg paid several visits to the latter “for the express purpose” of discussing the toilet habits of their charges. The chimpanzees, noted Kellogg, “move their bowels four to six times daily.” All the more to throw at zoo visitors. Kellogg effected a habit of dressing in immaculate white suits, but probably not on the second and third visits.
Kellogg didn’t gather data on the regularity of “wild men,” but someone else sure did. In the early 1970s, epidemiologist A. R. P. Walker held a post at the South African Institute for Medical Research, affording easy access to Bantu people and others “pursuing a primitive manner of life.” In his travels through South African villages, Walker noted that “unformed stools are frequently encountered among rural Bantu.” One man’s ruined footwear is another’s eureka moment. The Bantu, Walker knew, were almost never diagnosed with Western digestive diseases. Was it because they ate so much fiber? Did their woody digesta exit the colon too quickly to inflict harm?
Walker got busy clocking stool: British versus Bantu. Subjects swallowed radio-opaque pellets and then “voided” into plastic bags that they labeled with the date and time. The bags were X-rayed* so researchers could see exactly how long it took the pellets to complete their journey. As with foot races, so with digestion: the slowest third of the Bantu were quicker than the fastest third of the Caucasians. This was because, Walker assumed, the Bantu ate a shitload of insoluble fiber in the form of millet and corn porridge.
Walker was the man behind bran. Papers published by him and, more recently, his research partner Denis Burkitt, fueled a decade-long fiber craze. Americans were forcing down unprecedented amounts of bran muffins, oatmeal, and high-fiber breakfast cereals. Whorton cited a 1984 survey that found a third of Americans eating more fiber to stay healthy.