review, which means they have others working in the same field read the data and approve the conclusions. All reliable scientific journals require peer review before publishing a study.
Are the study’s conclusions reasonable?
If you find a study’s conclusions illogical, chances are the researchers feel the same way. In 1990, the Nurses’ Health Study reported that a high-fat diet raised the risk of colon cancer. But the data showed a link only to diets high in beef. No link was found to diets high in dairy fat. In short, this study was begging for a second study to confirm (or deny) its results, and in 2005, a large study of more than 60,000 Swedish women, reported in the American Journal of Clinical Nutrition, showed that eating lots of high-fat dairy foods actually reduced the risk of colorectal cancer.
EXTREME NUTRITION: CANNIBALISM
Cannibalism, from Canibales, the name early Spanish explorers pinned on a tribe in the West Indies, is one of civilized mankind’s strongest taboos, but anthropologists know that men and women have been tossing their friends and neighbors and relatives and defeated enemies onto the fire or into the stew pot ever since there was a written or drawn record of human activity.
The heyday of cannibalism reports was the Age of Exploration when stories of man-eating savages went along with virtually every voyage to the New World. Clearly, many of the terrifying tales were true, but the cannibal label was also used to belittle or demonize unknown or resistant peoples.
In fact, cannibalism has crept into virtually every society, civilized and not, driven by religious or cultural ritual such as the idea that devouring the heart of a brave man confers bravery upon the diner, but more commonly by simple necessity of survival during famine. In 1609, for example, George Percy, an original member of the Jamestown Colony in Virginia, wrote: “ now famin beginneinge to Looke gastely and pale in every face, thatt notheinge was Spared to mainteyne Lyfe and to doe those things which seame incredible, as to digge upp deade corpes outt of graves and to eate them. And some have Licked upp the Bloode which hathe fallen from their weake fellowes.”
Although they did not reach into graves, members of the Donner Party, caught in winter storms and starving as they tried to cross the Rockies (1846–1847), were also driven to cannibalism, as were those caught in the dreadful 842-day Siege of Leningrad (1941–1944) when more than 800,000 people starved to death; in China during the Great Leap Forward (1958–1961); and high in the Andes among the young athletes stranded after the crash of Uruguayan Air Force Flight 571 (1972).
But this is Nutrition For Dummies, not History For Dummies, so what you want to know is this: How nutritious is human flesh? According to James Cole, Senior Lecturer in Archaeology a lecturer on human origins at the University of Brighton in England: Very.
Human bodies, like other animal carcasses are red meat, fat, and offal. Based on data from four (dead) male adults, Cole estimates that a whole, cooked human body serves up about 82,000 calories. At a recommended 2,500 calories a day for an average adult male and 2,000 for an average adult woman, that’s about 34 days’ worth of sustenance for the former and 43 for the latter. A piece at a time, Cole rates a human arm at about 1,800 calories; a leg at 7,150; the lungs, liver, and alimentary canal about 1,500 calories each; the bundle of brain, spinal cord, and nerve and trunk about 2,700 calories. The brave heart? A mere 122.
Of course, while law-abiding folks are unlikely to slice, dice, and serve other folks anytime soon, other species are doing in their fellows day after day. The list of cannibalistic creatures who eat their enemies, their lovers, or their offspring includes fish such as the tiger shark and walleye, cute and cuddly prairie dogs, hamsters, hedgehogs, some snakes, caterpillars, ladybugs, spiders, some toads and tadpoles, hermit crabs, ducklings, cats, dogs, and polar bears (the last three often kill and sometimes consume sickly newborns). Chickens also make the list — but their cannibal dish is eggs not chicks.
And by the way, cannibalism is a species-neutral term. The word for people eating people is anthropophagy from the Greek words anthropos meaning “human being” and phagein meaning “to eat.”
Chapter 2
Digestion: The 24/7 Food Factory
IN THIS CHAPTER
When you see (or smell) something appetizing, your digestive organs leap into action. Your mouth waters. Your stomach contracts. Intestinal glands begin to secrete the chemicals that turn food into the nutrients that build new tissues and provide the energy you need for work, pleasure, and everyday life. This chapter provides a basic primer on the digestive system from start to finish with a few stops along the way to explain how you metabolize everything from apples to zucchini.
Introducing the Digestive System
Your digestive system is a collection of organs specifically designed to turn complex substances (food) into basic components (nutrients). These organs form one long, exceedingly well-organized tube that starts at your mouth, continues down through your throat to your stomach, and then goes on to your small and large intestines to end at your anus.
In between, with the help of the liver, pancreas, and gallbladder, the usable (digestible) parts of everything that you eat are converted to simple compounds that your body can easily absorb to burn for energy or to build new tissue. The indigestible residue is bundled off and eliminated as waste.
Figure 2-1 shows the body parts and organs that comprise your digestive system.
© John Wiley & Sons, Inc.
FIGURE 2-1: Your digestive system in all its glory.
The digestive process run by these organs works in two simple ways, one mechanical and one chemical.
Mechanical digestion takes place in your mouth and your stomach. First, your teeth break food into small, easy-to-swallow pieces that slide quickly from your mouth down through your esophagus (throat) to your stomach. Here, a churning action called peristalsis continues to break food into smaller particles and then moves the particles along to your small intestine, where the churning and breaking continues.
Chemical digestion occurs at every point in the digestive tract where enzymes and other substances, such as hydrochloric acid (from stomach glands) and bile (from the liver), dissolve food, releasing the nutrients inside.
The rest of this chapter explains exactly what occurs and where along the digestive tract.
Digestion: One Step at a Time
Each organ in the digestive system plays a specific role in the digestive drama. But the first act occurs in three places rarely listed as part of
