Deadly Harvest: The Intimate Relationship Between Our Heath and Our Food (12 page)

Antinutrients

Antinutrients are undesirable substances in food that work against the good nutrients and often disrupt the inner workings of the body. They are usually secreted by plants to kill predators such as germs, fungi, and insects. In other words, antinutrients are often naturally occurring germicides, fungicides, and insecticides.

Grains are also linked to colon disorders, including irritable bowel, colitis, colon cancer, and celiac disease. Full-blown celiac disease has symptoms of diarrhea, depression, vitamin deficiency, mineral deficiency, epilepsy, stunted growth, and osteoporosis. These conditions had been observed for centuries. It is astounding to think that it was only in the 1960s that a substance in grains known as gluten was found to be the cause.

Gluten is more properly called “the gluten complex,” because it is not a single compound but a cocktail of many similar proteins. The human system is particularly irritated by the cocktail found in wheat, followed by rye, barley, and oats. However, in Asia, sensitivity to the gluten cocktail found in rice is also known. Indeed, all grains contain gluten in some form or another and all of them cause trouble in the human system.

VEGETABLES AND SALADS

“
Plant food” or vegetation has been the major component of the human food supply since our origins. Some creatures, like our cousin the gorilla, are designed to eat tough vegetation like twigs, bark, stringy leaves, and fibrous stalks. However, humans are not able to digest these plant parts. Moreover, our ancestors did not cook their plant food either, so they focused on the young and succulent plant parts. When we think of vegetables, we do not think of them as a botanist does, as distinct parts of a plant with different functions. However, each part has its own nutritional profile and a role to play in our diet. Even today, we eat from a wide variety of plant parts, sometimes raw in salads and sometimes cooked.

Above ground, the edible part can be the stem, bud, leafstalk, leaf, bean pod, or the immature flower. In addition, there are some fruits, such as the avocado and tomato, which are included in the vegetable category. Indeed, most people think of them and use them as vegetables, so they are surprised to hear that, botanically, avocado and tomato are fruits. A large percentage of our ancestors’ food supply came from vegetation that was levered out of the ground with a digging stick. Today, we still eat many foods that grow underground—roots, tubers, bulbs, and corms (solid bulbs).

Most of the vegetables we use today have been known since ancient times. Merchants, traders, and empire builders spread them around the Old World. The Romans in particular moved plants around their territories wherever they would flourish. Later, the Spanish, Portuguese, Dutch, and British spread vegetables that they found with the Inca, Aztec, and Maya, to the rest of the world. During all this time, gardeners were hybridizing and “improving” the species, so that it is often uncertain just what the original, wild species was like.

The U.S. Department of Agriculture (USDA) does not subdivide its Vegetable Group: they classify French fries and ketchup as vegetables just like lettuce and broccoli. As this example shows, it does indeed make a difference just what kind of vegetable we are eating—not all “vegetables” conform to the type of plant food to which we are naturally adapted. It is also true that our Pleistocene ancestors in East Africa would not be familiar with a single vegetable species in our present food supply. For reasons that will become clear later, we divide vegetables into two new groups, “starchy” vegetables and non-starchy vegetables.

Starchy Vegetables

Certain plants have evolved the ability to store food during times of plenty to see them through times of hardship. Some of them store the food in the form of starch. In most cases, the roots are pressed into service as storage organs. Examples are Old World vegetables such as beets from southern Europe, parsnips from temperate Europe, and carrots from Afghanistan. An aboveground example is the chestnut. This might come as a surprise, for the chestnut is usually lumped in with all the other tree-nuts. However tree-nuts typically are rich in oil (around 50%), rich in protein (up to 25%), and low in starch. The chestnut is very starchy and very low in protein and oils (both around 1.5%). Its nutrient profile is like other starchy vegetables and we therefore class it as such.

However, it is a tuber from the New World that has relegated all Old World starchy root vegetables to minor players—the potato. The Spanish conquistadors first brought it back to Europe from Incan Peru in the 16th century. A relative of the tomato plant, it was a small, wrinkled tuber, rather like a walnut. For a long time, Europeans did not know what to do with it; some farmers grew it to fatten their pigs. Then, in the 1800s, the British blockaded France during its war against Napoleon. With their regular foods in short supply, the French developed ways to incorporate potatoes into their daily diet.

Potatoes are not even edible in their raw state, as the human digestive system can only cope with them if they are cooked—they require processing. So, it is only in the last 200 years that the potato entered the diet. But its success was immediate, widespread, and rapid. It has relegated every other root vegetable to the sidelines. However, this has not been a beneficial development.

We all love the potato: it is the most commonly consumed vegetable, served up in dozens of tasty and imaginative ways. Unfortunately for us, its consumption is linked to readily observed conditions, such as obesity, diabetes, high cholesterol, heart disease, and cancers, because of abnormal surges in blood sugar. There are potential difficulties as well with some of the other “starchy” root vegetables, such as the aforementioned parsnip, beets, and carrots.

We think of the potato as a safe food to eat—even if it might be fattening—but very few people are aware that the potato is also mildly toxic. Potato consumption is directly linked to allergies, bowel disorders, confusion, and depression. Every year, dozens of people are hospitalized with potato poisoning, and many more cases go undiagnosed. These problems are directly linked to antinutrients in the potato that our bodies can’t cope with. We will deal with the science behind these startling assertions in Chapter 4.

Non-Starchy Vegetables

Not all underground vegetables are starchy. For example, turnip and radish, which both originated in Asia, are non-starchy, as are bulbs such as onion and garlic from Asia and the leek from the Middle East. Corms such as Chinese water chestnut are also non-starchy. Unlike the starchy roots, they mostly get their bulk from another compound called “inulin.” We will reveal the significance of this in Chapter 4 when we look at the science behind our food supply.

The vegetables from above ground cover a huge range of plant parts: stems, such as asparagus from the Mediterranean and kohlrabi from Europe; buds, such as Brussels sprouts from Belgium; leafstalks, such as celery from the Mediterranean and rhubarb from Asia; leaves, such as Europe’s cabbage, lettuce, and spinach; immature flowers, such as cauliflower from Europe, broccoli from Turkey, and artichoke from the western Mediterranean; immature fruits, such as eggplant from southern Asia and cucumber from northern India; mature “vegetable-fruits,” such as tomato from Peru, avocado from Central America, and bell pepper from the Andes; edible bean pods, such as runner beans from tropical America; and edible fungi (mushrooms) from just about everywhere. Of course, today, these plants are grown all over the world, wherever farmers can produce them economically.

The tomato is an unusual case. First known to the Incas, 500 years ago the Spanish conquistadors brought samples back to their homeland from Peru. The tomato comes from the same family as deadly nightshade, so for a long time, Europeans, warned off by the bright red color, thought the tomato was drop-dead poisonous. Finally, some brave souls tried it and survived the experience without any ill-effects. About 200 years ago, the tomato made it into the food supply. Like the potato, it has now eclipsed all other Old World vegetables and conquered cuisines around the world. It is not without its drawbacks: it does indeed contain low levels of plant poisons
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and some people react to them, with arthritic symptoms, for example.
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It is hard to believe, but true, that the tomato was unknown to Italian cuisine just 200 years ago. The chili pepper, which gives Asian cooking and curries their fiery properties, was unknown before the Spanish introduced it (from Mexico) to India and Malaya 400 years ago.

We have seen just how many new non-starchy vegetable foods have been introduced into the human diet all around the world relatively recently. Remarkably, with the exception of chili pepper, they are all beneficial entries to the diet—none of them seems to have a major adverse effect on human health. The chili pepper, however, irritates the lining of every part of the digestive tract: it causes the colon to become more porous, allowing germs, fungi, and food particles to enter the bloodstream. This can lead to a whole range of conditions from allergies to migraines to a depressed immune system.

FRUIT GROUP

Imagine that you are one of our ancient ancestors rummaging for food on the African savanna 60,000 years ago. You see a familiar ripe fruit and pounce on it—you know it is going to taste good! Fruit and humans have evolved together over eons to help each other. The fruit wants its seeds dispersed, while humans want nutritional gratification. The fruit immediately rewards you with its gratifying, jazzy, sweetish taste, which is known as the “sugar reward.” Moreover, since fruit was a rare commodity on the African savanna, our brains are programmed to continue eating that sweetish thing until the supply runs out.

Our early ancestors of the African savannas would not recognize the fruits available in our modern supermarkets. First, our fruit selections are vastly different: apples, cherries, and plums originated in the Middle East, pears in Europe, grapes in the Caucasus, strawberries in America, oranges in China, and bananas in Malaya. Second, gardeners, through selective planting techniques, have heavily modified these different species from their original state since the farming revolution. One has to admire the persistence and foresight of those early New Stone Age farmers. They took the sour-sweet, woody crab apple of the region and patiently bred it over many generations so that it became a tasty apple. They did the same with many other fruits that are familiar to us today, such as the plum, pear, and cherry. However, in the last century, the process has accelerated: agro-industrialists have selectively bred modern fruits to have an attractive appearance, long shelf life, few seeds, less fiber and a powerfully sweet taste.

Ancient farmers developed most of these fruits in temperate regions. More recently, with the immense growth in global shipping during the age of European exploration, many tropical fruits became popular. The most common is the banana, originally from the jungles of Malaya, along with the pineapple from the Caribbean, the mango from India, and the papaya from Central America. The watermelon is from tropical Africa and it is just about the only plant food that our Pleistocene ancestors would have recognized. The one we eat today is a sweet-tasting descendant of the bitter-juiced tsama melon, still used by the San as a water source. Just in the 1970s, enterprising New Zealanders provided the most recent addition to mass-market fruits, the kiwi fruit. They bred it from the Chinese gooseberry, whose origins lie in subtropical parts of China.

So, today’s common fruits are, in many respects, not like the fruits in our Savanna Model. There are potential snags related to the massive increase in sweetness from various kinds of natural sugars, some of which are relatively harmless and others may pose problems. Fruits rich in the wrong sugars can aggravate pre-existing ailments such as diabetes, allergies, high cholesterol, and cancers. There is a massive rise in indigestion in the U.S. and one major reason is eating fruits at the wrong point in a meal: our bodies were not built to handle the mixing up of unfamiliar foods. Different fruits have different proportions of each kind of sugar. Later in the book, we will discuss what fruits to choose and how much and when to eat them.

PROTEIN-RICH FOODS OF ANIMAL ORIGIN

At the U.S. Department of Agriculture (USDA),
meat
is the term applied to the flesh of domesticated mammals, such as cattle, pig, and sheep. More conventionally, this is known as “red meat,” which is the designation used here. Similarly, “game” refers to the flesh of any wild land animal, such as wild boar or pheasant. “White meat” refers to flesh taken from domesticated birds, such as chickens, and “seafood” refers to fish and shellfish. We will look at both wild and domesticated sources of animal products. The USDA does not include certain classes of animal foods that were common in our ancestors’ diet—the “exotic” categories of reptiles, worms, insects, and gastropods (snails and slugs). This is fair enough as these foods are not commonly eaten in developed countries, although there are many societies around the world that still make use of them.

Red Meat and Game Mammals

We saw with the San how mammals such as springhare (a kind of rodent), porcupine, and warthog were part of our ancestral diet. Less commonly, there would be big game such as antelope and, occasionally, giraffe and even leopard. We now look in detail at sources of meat in our food supply, starting first with farmed meat and then wild meat.