Real Food Part 10

The fiber, B vitamins, vitamin E, and antioxidants in whole wheat, brown rice, and other whole grains prevent obesity, diabetes, heart disease, and colon cancer. The government recommends three servings of whole grains daily, but the average American eats only one. The recent emphasis on the benefits of whole grains has led to an explosion of commercial whole grain breads, pasta, and baking mixes; quality is improving, too. For busy people and nonbakers, this is good news. The Oldways Preservation Trust, a food think tank, has devised the Whole Grains Stamp to alert buyers to foods containing whole grains.

Whole grain flour is nutritionally superior, but in certain baked goods, white flour gives a better texture. With pie crust, for example, you can just about get away with using one third whole wheat flour; add any more and the crust crumbles at the touch. You will have to make up your own mind about baked goods. For me, the occasional white flour crust (with lard and b.u.t.ter, of course) strikes an acceptable compromise between health and pleasure.

The complex carbohydrates in whole grains and legumes can be difficult to digest, causing bloating or cramps. Gluten intolerance, or celiac disease, is another problem common with wheat. All grains and legumes contain phytic acid, called an antinutrient because it reduces absorption of calcium, iron, magnesium, zinc, and other minerals. Other antinutrients in grains and beans, called protease inhibitors, interfere with protein digestion by blocking protease enzymes that break it down.

Yet these nutritional drawbacks have not stopped us from eating grains and beans. To aid digestion, reduce phytic acid, and increase nutrients, people all over the world sprout, soak, ferment, and cook corn, rice, wheat, and beans. All over the world, grains are a staple food for the poor. Dependence on grains would be catastrophic without these time-honored methods. In effect, foods are partially predigested by such kitchen tricks.

In the Americas, for example, conquistadores and colonists saw that the Aztecs soaked or ground corn with lime, but they didn't know why. Later, corn traveled to Europe without the tip about using lime, and people suffered for it. "Peasants who lived on corn throughout the winter came down with 'corn sickness,'" writes Betty Fussell in The Story of Corn. In 1771 an Italian named it pellagra (rough skin), but its cause remained mysterious. It was thought, perhaps, to be triggered by a kind of corn rot. Not until 1915, when the National Inst.i.tutes of Health appointed Dr. Joseph Goldberger to investigate an epidemic of pellagra in the American South, did anyone suspect that pellagra was diet-related. Today we know that treating corn with lime (or some other alkali) liberates its vitamin B3, and that pellagra is caused by lack of vitamin B3, which is vital for metabolism.

Ancient cooks knew all this. An early recipe for cereals was pounded gruel. The Greeks ate a fermented, slightly alcoholic barley porridge, while Native Americans made a corn mush. After rudimentary porridge, the next development in grain cookery was unleavened bread. In the Old Testament, Ezekiel commands, "Take wheat, barley, beans, lentils, millet, and spelt and put them in one vessel and make bread of them." This pa.s.sage also calls for sprouting the grains. Essene bread, a thin wafer of sprouted wheat flour, was probably the unleavened bread the Jews carried as they fled Egypt. Rich in vitamin C and protein, sprouts are remarkably nutritious, and many people who cannot digest wheat can eat sprouted grain breads, which are sold in whole foods shops.

Following traditional culinary and nutritional advice, I first soak the ground corn overnight with a pinch of baking soda when I'm making polenta, grits, or corn bread. According to Anson Mills, the miller of heritage varieties of American wheat, rice, and corn in Charleston, South Carolina, where I buy corn, lime also accentuates the floral flavors and aroma of grits. I soak rice for an hour and dried beans overnight, again with a pinch of soda. In effect, soaking is a mild form of fermentation.

THE OTHER WHOLE GRAINS.

As with apples, pork, and every other food, monoculture reigns in grains. Today the dominant crops are wheat, corn, and rice, but this is a historical blip. For millennia, people have eaten dozens of others.

* Amaranth. An Aztec staple, amaranth has no gluten.

* Barley. Grown by the Egyptians, barley has a lot of fiber and needs long cooking. Pearled barley is slightly refined and cooks more quickly.

* Buckwheat. A cousin of rhubarb, not a grain, buckwheat contains the antioxidant rutin and is famous in American pancakes, j.a.panese soba noodles, and Russian kasha.

* Kamut. An ancient wheat with large, yellow, sweet grains. More protein and fats than durum wheat.

* Millet. A small, round grain with a delicate, nutty flavor, millet is a staple in India and delicious with b.u.t.ter.

* Oats. Buy whole rolled or steel-cut oats and soak overnight in water with a spoonful of yogurt or whey.

* Quinoa. Cultivated by the Incas, quinoa is a member of the beet family. Light and fluffy, it cooks quickly.

* Rice. One of the most easily digested grains, rice may be brown, red, or black.

* Rye. With more fiber than wheat, rye makes a dense bread and superior sourdough.

* Spelt. An ancient wheat, with more protein, it is often tolerated by people who can't eat wheat.

* Teff. A kind of millet with a very tiny, somewhat sweet grain, it is a staple in Eritrea and Ethiopia, where they make a spongy fermented pancake called injera.

* Wild rice. A swamp gra.s.s, not technically a rice, with a strong flavor and more fiber than rice.

The next development in grain cookery also used fermented grains, this time in the form of sourdough and yeast bread. The first leavened bread was invented by the Egyptians around 2300 BC. The early bakers let flour and water sit uncovered for several days, allowing it to bubble and expand from wild yeast spores in the air. Essentially, this is the same sourdough starter traditional bakers use today. Next, one adds flour and water to the starter, kneads the dough, and lets it rise with the action of the yeast. A good baker keeps a bit of starter for the next batch. Some starters have lasted for generations in the kitchen.

Natural, spontaneous leavening was the basic method of Western bread baking until the twentieth century, when commercial yeast was introduced. In 1961, bread suddenly became industrial with the invention of a technique by the Flour Milling and Baking Research a.s.sociation in Chorleywood, England. The "Chorleywood bread process," as it is known, uses chemical improvers and low protein wheat, even though high protein wheat makes superior bread. Fermentation is dispensed with altogether. Unfortunately, "it's the fermentation time that makes bread digestible," says John Lister, a traditional miller at s.h.i.+pton Mills, in the Cotswolds in England.3 Real bread also tastes better.

Perhaps you think soaking corn meal in soda, or finding a bakery that makes proper bread, is quaint, peculiar, or just too much trouble. I hope not. It's worth the effort, for health and flavor. But my commitment to old foodways, as historians like to call these culinary legacies, is nothing compared to advocates of the Stone Age diet, whose view of the ideal diet is far more radical. They believe that bread itself- not only industrial bread- is bad for you, and it's worth hearing what they have to say.

In 1985, Dr. Boyd Eaton wrote a seminal article in the New England Journal of Medicine called "Paleolithic Nutrition." Eaton noted that high blood pressure, diabetes, heart disease, and cancer were rare among modern carnivorous hunter-gatherers such as the !Kung in the Kalahari Desert, aborigines in Australia, and Ache in Paraguay. Loren Cordain, a professor at Colorado State University, was inspired by Eaton's work and decided that we should eat like Stone Age people. What does that mean?

In The Paleo Diet, Cordain calls for liberal amounts of green vegetables, fruit, fish, game, and pastured meat, poultry, and eggs. On that much, experts agree, but Cordain goes farther- right back to the Stone Age. His diet forbids all farmed foods, including grains, legumes, dairy, potatoes, and honey. Cordain is particularly critical of cereals, which he calls "nutritional lightweights" compared with meat, fish, and produce. Per calorie, meat and fish contain four times more vitamin B3 than whole grains. A one-thousand-calorie serving of vegetables contains more calcium, magnesium, pota.s.sium, and iron than a similar serving of whole grain cereal. The vegetables also have five times more vitamin B6, six times more B2, and nineteen times more folic acid than whole grains.

When I delved into Stone Age nutrition, I was surprised to learn that the rise of farming was not entirely good news for human health. Archaeologists agree that early farmers had diseases and conditions not seen in hunter-gatherers, including parasites, syphilis, leprosy, tuberculosis, anemia, bone infections, and rickets.

On the Neolithic diet, humans got shorter, a reliable sign of poor nutrition. Farming did cause a population boom- largely because grain is an inexpensive, easily stored source of calories- but general health declined.4 The proponents of Paleolithic diets have a point: the body does not require wheat, corn, chickpeas, or milk, which are relatively recent additions to the diet. All the essential nutrients are found in Stone Age foods. Given the emphasis on the nutritional value of whole grains today, it is perhaps surprising that you can get plenty of vitamins, minerals, and fiber without grains, but true. As for dairy, East Asian cultures thrive without it. Dr. Ben Balzer, an expert on Paleolithic nutrition, says that for the same calories, the typical hunter-gatherer diet has more vitamins, minerals, omega-3 fats, and antioxidants than the modern diet.

Americans do eat too many grains and refined grains. The main villain is corn, in three forms: corn-fed beef, corn oil, and corn syrup. On factory farms, cattle eat corn that is too rich in omega6 fats; then we eat the beef and milk lacking the omega-3 fats we need. Corn oil, the main source of excess omega-6 fats, is a major cause of obesity, diabetes, and heart disease. Corn also becomes high fructose corn syrup, the main caloric sweetener in junk food. Intake of high fructose corn syrup grew by more than 1,000 percent between 1970 and 1990, far exceeding changes in consumption of any other food. The rise of corn syrup mirrors the increase in obesity.5 Fructose also raises insulin, blood pressure, and triglycerides. If you take only one piece of advice from the Stone Age diet, stop eating all forms of industrial corn. It's far better to eat this delicious native vegetable in the traditional way: boiled with b.u.t.ter or in whole corn grits- ideally soaked first.

The Stone Age diet of whole foods has much to recommend it, but I'm not convinced it's necessary to give up all farmed foods. Our saliva and digestive tract contain enzymes such as amylase to digest starch. During the last Ice Age in North America, Siberia, and northern Europe, a wild wetland tuber called wapato was prolific, suggesting that ancient humans ate potatoes. What matters most is how we farm and how we prepare foods.6 I eat mostly Stone Age foods, but in my kitchen you'll also find traditional farmed foods, including sweet potatoes, raw milk cheese, lentils, whole grits, raw honey, and miso, a j.a.panese fermented soybean paste. I know we've been eating some of these foods for "only" two or four or ten or thirty thousand years- not three million- but that's long enough for me.

Traditional and Industrial Soy Are Different.

IN MY VEGAN AND low-fat days, I was sometimes wistful for chocolate pudding, peach milk shakes, and apple pie a la mode. To satisfy my hankering for dairy, I bought soy "milk" and "ice cream." Millions of people began to eat soy foods, too- perhaps for the same reason. In supermarkets today, the soy milk section is almost as big as the dairy department, and that's no accident. Once soy milk appeared in the chilled dairy case, next to the milk, sales took off. Not long ago, the soy beverage was an odd creature, a canned drink for people on funny diets. Now, dressed in gable-top milk cartons, soy beverages look much like another kind of milk.

Long popular with vegetarians as a meat subst.i.tute, soy foods went mainstream with the rise of the "heart-healthy" diet. The U.S. government says twenty-five grams of soy protein daily, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. Soy isoflavones are antioxidants, and its amino acids keep insulin in check. Soy may also prevent osteoporosis, hot flashes, prostate cancer, and some breast cancers.

These health benefits are impressive, and I began to wonder if the soy foods I was eating were traditional foods by my rough definition. Do they have a long history in the diet? Are they made pretty much the way they used to be? It turns out that some soy foods are traditional, others less so. This is what I learned about the remarkable soybean.

In China five thousand years ago, the soybean was grown to feed animals and build soil fertility, but not for human consumption. It turns out that we don't digest soybeans easily. In the Chou Dynasty (1134-246 BC), the Chinese learned to ferment soybeans to make them digestible to humans, and after this discovery, various fermented foods like j.a.panese miso sprang up. Bean curd was fermented, as in Chinese sufu, Indonesian tempeh, and j.a.panese tofuyo, or "spoiled milk."

Like all legumes, soybeans contain phytic acid, which, as we've seen, is called an antinutrient because it reduces absorption of calcium, iron, magnesium, zinc, and other minerals.7 Diets high in phytic acid stunt growth. Cooking reduces phytic acid somewhat, and both soy milk and tofu are cooked. But fermentation is better; fermented tofu contains more available iron.8 Soy also contains protease inhibitors, which interfere with protein digestion by blocking protease enzymes that break it down. Protease inhibitors are reduced by cooking or fermentation.9 At first the chemistry of soybeans seemed arcane to me, but the effects are important. After World War II, the United States sent soybeans to hungry people in j.a.pan, Korea, and Germany. When the Germans got headaches and stomach pain and lost weight, the Americans, guessing they were biologically different from Asians, stopped sending soy. Later, U.S. scientists discovered the necessity of fermenting soybeans- only to find that Asians knew the secret all along.

Many people think that soy provides complete protein, but that's not quite so. Soy does have all the essential amino acids, but only trace amounts of two: cysteine and methionine. The body cannot make methionine. It can make cysteine, but only from methionine. Only animal products contain high-quality protein, with the right amount and proportion of all the amino acids. Soy is also said to contain vitamin B12, but that's misleading. The compound in soy that resembles B12 cannot be used by the body. True vitamin B12 is found only in animal foods, with one partial exception. Some B12 is created during fermentation by microorganisms- which are, of course, tiny animals. Thus yeast and beer contain trace amounts of B12. Vitamin B12 is essential, but a small quant.i.ty is enough. Eating fermented soy sauce may be one reason Asians were able to survive protein-poor diets during famines.

In the United States, the soybean was little known until the 1920s, when the government paid farmers to grow it. Animals on factory farms eat a lot of soybean cakes, but as a raw commodity, soybeans don't fetch a very high price. With a bit of tinkering, however, the soybean can be made much more profitable. In a remarkably short time, the food industry transformed the soybean from animal fodder into thousands of convenience foods worth billions of dollars.

The modern soybean yields two products for human consumption: oil and protein. Rare a hundred years ago, soybean oil is now the most popular oil in the world. In culinary-historical terms, it's an overnight sensation. Annually, Americans consume eighteen billion pounds of soybean oil, some 75 percent of the oil they eat. Alas, most soybean oil is industrial. About 85 percent of the U.S. crop is genetically engineered, and most of it is treated with heavy doses of nitrogen fertilizer and pesticides. Soybean oil is pressed under great heat and pressure, and the pulp is treated with solvents like hexane to extract the last drops of oil. The oil may be washed in lye, deodorized, and bleached. It's no surprise that industrial soybean oil emerges oxidized and carcinogenic.10 Cold-pressed oil from organic soybeans is better; its polyunsaturated fats and vitamin E are undamaged. However, soybean oil is rich (53 percent) in the omega-6 fat linoleic acid (LA), and as we've seen, we already eat too much LA. That's why soybean oil is the only soy food that Barry Sears, author of The Soy Zone, does not recommend. The flavor is nothing special, either, and olive oil contains all the omega-6 fats you need.

Unusually for a bean, the soybean contains more protein (38 percent) than carbohydrate. When soybean oil is made, a great deal of protein remains. Ingeniously, soy producers have transformed this leftover into the key ingredient in imitation sausages, milk, and cheese. Called soy protein isolate, it's 90 percent protein. As usual, industrial production does it no favors. Vitamins and the amino acid lysine are lost, while aluminum residue remains. Soy protein isolate does not have the FDA status known as GRAS (Generally Recognized as Safe).

With the invention of soy protein isolate, the market for soy foods exploded, and now it's the base for chips, pasta, meatless sausage, and dairylike foods. The challenge is making these imitation foods taste like the real thing. As fans of the tofu stir-fry know, the naturally bland soybean is a good platform for other flavors. It can also be "beany" or bitter. Texture is another problem: soy "cheese" is distinctly rubbery. Aware of all this, industry scientists are hard at work on soybean hybrids and processing methods to improve soy texture and flavor. Meanwhile, industrial soy foods need a boost in the flavor department. Typical ingredients in soy "ice cream" are sugar, corn oil, soy protein isolate, food starch, and flavoring. Fake cheese often contains hydrogenated oils, and MSG is common in savory foods like hot dogs.

Because flavor is not its strong suit, much of the soybean's appeal rests on health claims. Evidence for some benefits of soy seems strong. Soy isoflavones reduce LDL. As part of a diet low in refined carbohydrates, lean soy protein regulates blood sugar and insulin. That's the message of The Soy Zone, by Sears, who devised a soy diet (with, I noted, added fish oil and vitamin B12) for his vegetarian daughter.

Asians have lower rates of osteoporosis than Americans, and some studies show higher bone density with soy-rich diets. Is soy responsible? It's not clear. Phytic acid in unfermented soy reduces calcium absorption.11 In Asia and elsewhere, traditional diets also include calcium-rich bone broth and ample vitamin D, which is vital for calcium absorption. In fact, milk is far superior to soy as a source of calcium. One cup of soy drink has 10 milligrams of calcium, while milk has 300 milligrams, and more of the calcium in milk is absorbed.

Because soy is rich in isoflavones (plant estrogens), it's a natural remedy for symptoms of menopause. But the research is mixed.12 Several recent studies have found that soy isoflavones were no better than a placebo in treating hot flashes. Moreover, large doses are not without risk; eating 60 grams of soy protein daily for only one month disrupts menstrual cycles.13 On soy and breast cancer, the data are voluminous, the claims competing, and the results unclear.14 Some researchers believe soy prevents breast and prostate cancer, while others suggest it causes both. Genistein, the main soy isoflavone, can encourage cancer in breast cells, but genistein supplements are not necessarily equivalent to the genistein in whole soy foods.15 In 2001, researchers who reviewed studies on soy and breast cancer said, "The honest response to each of these diametrically opposed claims is that no convincing data exist to support either claim."16 It may be that the estrogens in soy are bad for estrogen-dependent breast cancer, but not other types of breast cancer.

Given the uncertainty, most experts recommend soy foods rather than isoflavone pills.17 Foods may be superior because pills don't contain all the biological compounds originally in soy, but no one knows. The breast cancer specialist Dr. Susan Love, who believes soy can be beneficial, says that "soy food and soy supplements are not the same. Soy as food is probably safe for women with breast cancer, but the final answers aren't in yet."18 Soy should be viewed as part of a diverse diet, not as a nutritional silver bullet. The island of Okinawa, about four hundred miles off j.a.pan, makes a fascinating case study for diet and disease. More Okinawans reach the age of one hundred than any other population in the world. Islanders have less heart disease, stroke, and cancer than mainland j.a.panese. Fans of soy note that Okinawans eat more soy protein than any other group: one hundred grams daily, versus forty grams on mainland j.a.pan, and a mere four grams in the United States.

If food does account for the Okinawans' extraordinary health (which seems likely), I'm inclined to credit the entire diet- including raw fish, antioxidant tea, and traditional soy foods. Islanders also eat fewer calories, twice as much fish, and twice as many vegetables as mainland j.a.panese. An American wis.h.i.+ng for the longevity of an Okinawan would need to do more than sprinkle one hundred grams of soy protein on his cereal. It's always better to eat real foods than pop pills. Soy protein reduces cholesterol, for example, but isoflavone supplements don't. An Okinawan proverb sums it up nicely: "One who eats whole food will be strong and healthy."19 In traditional Asian cuisine, soy is part of a diverse diet. Tofu is typically eaten with an animal protein such as fish broth, which provides complete protein and reduces the effects of phytic acid.20 Many foods, such as natto, miso, and often tofu, are fermented. There is a bewildering variety of traditional tofu recipes. Indonesian tempeh, a chewy soy cake made with rice or millet, is quite unlike silky j.a.panese tofu, for example. In China, various pungent fermented tofus, pickled and aged in rice wine, chillies, and spices, are used in specific dishes, such as steamed pork and congee (a rice gruel).

The most famous fermented soy food is soy sauce. Traditionally, whole soybeans are slowly fermented to break down the protein and develop a distinctive briny flavor. Industrial soy sauce is made with defatted soy protein, wheat, sugar, preservatives, and coloring. Using defatted soybeans speeds fermentation because complex oils need not be broken down into fatty acids, but soy sauce made from defatted soy lacks the flavor, aroma, and health benefits of the real thing.

Edamame, an ancient j.a.panese delicacy of fresh, young, whole soybeans, is not a fermented soy food. The beans are merely boiled. Perhaps young beans are easier to digest than mature, dried beans and thus don't require fermentation; I don't know. Bright green edamame tastes a bit like a sweet young lima bean and is delicious with salt.

TRADITIONAL SOY FOODS.

Many soy foods are common in more than one Asian country. For example, fermented bean sauce is originally Chinese, but it turns up in Vietnamese and Thai dishes. You will find the following foods in whole food shops, good grocers, and Asian markets.

* Amazake. Sweet, cultured rice "pudding" (j.a.panese).

* Bean sauce. Salty, fermented soybean sauce, often spicy.

* Miso. Salty, fermented paste of cooked soybeans, aged for a year or more (j.a.panese).

* Natto. Salty topping of fermented, cooked whole soybeans (j.a.panese).

* Soy milk. Soybeans are soaked, ground, simmered, and pressed.

* Soy sauce. Salty, aged, fermented condiment, best made with whole soybeans.

* Sufu. Fermented tofu condiment regarded as medicinal (Chinese).

* Tahuri. Fermented tofu (Filipino).

* Tamari. Liquid left after miso is made, used like soy sauce; contains no wheat (j.a.panese).

* Tempeh. Fermented tofu cake often containing rice or millet (Indonesia).

* Tofu. The traditional soybean curd; may be firm or soft, grainy or silky; often fermented.

* Tofuyo. Fermented tofu said to be good for the stomach (j.a.panese).

HEALTH BENEFITS OF FERMENTED SOY.

* More digestible.

* Less phytic acid (thus more minerals).

* Fewer protease inhibitors (thus more available protein).

* True vitamin B12.

* More isoflavones21.

How much soy is beneficial? No one knows- or, rather, the experts don't agree. They can't even settle on how much soy was traditionally eaten in Asia or is eaten today. Proponents say daily consumption in Asia ranges from 40 to 100 grams of soy protein, but skeptics counter that j.a.panese and Chinese eat only 10 grams. Even allowing for differences in actual consumption within and between Asian countries, this wide range is probably due to selective reporting from the pro- or antisoy camps or both.

Fermentation is another factor. Critics argue that most soy in traditional diets was fermented, and for centuries it probably was, but unfermented soy is more common now. If fermented soy is better, any health benefits Asians enjoy may disappear as they begin to eat more industrial soy. Unfortunately, the following figures for actual, recommended, and maximum safe consumption don't distinguish between traditional and industrial soy. The best I can say for these wildly different numbers is this: they present an accurate- if frustrating- picture of the conflicting views about soy.

HOW MUCH SOY PROTEIN PER DAY? HARD TO SAY.

Grams Per Day Estimate of the typical American diet 4 Estimate (by soy critic) of j.a.panese and Chinese diets 10 HOW MUCH SOY PROTEIN IS IN A SERVING?.

The following foods have about 30 grams of protein and just under 30 milligrams of isoflavones.

8 oz extra-firm tofu 12 oz firm tofu.

16 oz soft tofu.

4 oz soy "cheese"

24 oz soy "milk"

32 oz soy "yogurt".

30 g soy protein powder.

Upper limits for safe consumption are important, because it is possible to eat too much soy. Excess genistein is toxic to the thyroid, which regulates appet.i.te, metabolism, mood, and libido. In 1999, as the FDA was considering the claim that soy can prevent heart disease, two FDA specialists told the agency their concerns about hypothyroidism. They wrote, "There is abundant evidence that some of the isoflavones found in soy . . . demonstrate toxicity in estrogen-sensitive tissues and in the thyroid. Our conclusions are that no dose is without risk."22 j.a.panese researchers found that 30 grams of roasted, pickled soybeans daily suppressed thyroid function in healthy people.23 They called the dose "excessive." Yet proponents recommend 40 to 50 grams of soy protein daily.

One group is particularly vulnerable to soy: babies. Many studies confirm that soy causes hypothyroidism and goiter in babies. Soy formula may stunt growth and disrupt hormones, s.e.xual development, and immunity. The dose of isoflavones in soy-based formula is huge: one thousand times greater than in breast milk.24 New Zealand, Canada, Ireland, Switzerland, and Britain advise caution in feeding soy to babies. One of the FDA soy experts cited above called soy formula "a large, uncontrolled, and basically unmonitored human infant experiment."25 Soy is a complex food, and there are no easy answers. I certainly would not feed soy to babies or children, and would advise caution for adolescents, whose s.e.xual development is incomplete. Vegetarians might consider what kind of soy foods they eat and how much, and women with breast cancer should consult a specialist familiar with the latest research. For me, industrial soy "milk" and other imitation foods flunk the real food test. This unique vegetable is more digestible, nutritious, and tasty when prepared in the traditional way. If you appreciate soy, do as Asian cultures have for two thousand years: eat traditional soy foods.

I Explain the Difference Between Good Salt and Bad.

FOR THOUSANDS OF YEARS, salt has been central to human life. Greek slave traders traded salt for slaves, giving us the expression "not worth his salt," and Roman legionnaires were paid in salt; salarium is the Latin root of salary. In Sanskrit, lavanya, suggesting grace, beauty, and charm, comes from lavana for salt. Many wars have been fought over salt supplies, and many political battles over salt taxes. Like fish, salt was prized by landlocked people, who burned salty marsh gra.s.s and added the ash to food.

We seek salt for good reasons. Salt stimulates the gastric juices, and it's necessary to emulsify, or digest, fats. Hydrochloric acid in the stomach (for digesting meat) is made with salt. Unrefined salt contains the electrolytes sodium, pota.s.sium, and chloride, which are essential for every cell function, including blood pressure, nerve signals, and muscle action. Chronic salt deprivation causes weight loss, inertia, nausea, and muscle cramps. In the kitchen, meanwhile, salt is indispensable. It enhances flavor, even making sweet things sweeter. Salt is a preservative, aids fermentation, and improves the texture of bread and cured meat.

Today, however, salt has a bad reputation. The psychology professor Paul Rozin has found that many Americans regard salt (and fat) as a toxin and believe even a trace amount is unhealthy. "This belief establishes a goal that is both extremely unhealthy, and unattainable," he says. Early studies did correlate salt intake and high blood pressure, but more recent research has been kinder to salt. In 1983, studies in the United States and j.a.pan found that dietary salt didn't affect blood pressure in most people significantly.26 In the 1990s, several U.S. and British studies concluded that salt itself is not the cause of poor health.27 In 2006, data from the prestigious NHANES II study showed that death from heart disease and from all causes rose with lower sodium consumption28 "Evidence linking sodium intake to mortality outcomes is scant and inconsistent," said the researchers. Yet doctors still routinely prescribe low-sodium diets for patients with hypertension and heart disease. According to Dr. Kilmer McCully, only a few people- about 20 percent- are "salt-sensitive." For most of us dietary sodium doesn't seem to affect blood pressure or heart disease risk. Meanwhile, many other factors raise blood pressure: too little pota.s.sium, stress, smoking, being overweight, and lack of exercise.

Three million years ago, Stone Age humans got all the salt they needed from eating meat and blood, fish, and sea vegetables; perhaps they occasionally dipped foods into seawater for salt. Later- probably around the time they began to eat more grain and other starches- humans became salt farmers, mining ancient seabeds for salt from the earth or gathering it from seawater. Archaeological evidence suggests that about four thousand years ago, humans produced salt in central China. Consumption of unrefined salt predates industrial diseases.

My friend Daniel Gevaert, who worked on our farm as a teenager many summers ago, taught me to appreciate real salt. Back home in France, he became an organic farmer, manufactured fermented soy foods, and bought a sea salt factory. Factory is not quite the right word, in that nothing much industrial happens there. From June to September, Atlantic sea salt is harvested manually with clay pans and allowed to dry naturally in the wind and sun. The factory is a simple shed, empty but for a chute. The salt dries gently as it flows along the chute, through screens that sort it into fine or coa.r.s.e grains. The salt is never washed, heated, or refined in any way, and nothing is added.

A few years ago, Daniel and his wife, Valerie, sold Danival, the company they founded, to a large French concern. That made me a little sad, but it will be several years before I finish the salt from my last visit to the factory near Bordeaux. Daniel's salt is a soft gray and slightly moist. It is rich in minerals and trace elements, with an exquisite briny flavor. (Danival and other unrefined sea salts are sold in the United States under the brand Celtic.) Typical commercial salt, by contrast, is an industrial leftover. First the chemical industry removes the valuable trace elements and heats it to twelve hundred degrees Fahrenheit. We get what's left: 100 percent sodium chloride, plus industrial additives, including aluminum, anticaking agents to keep the salt pouring smoothly, and dextrose, which stains it purple. Salt is then bleached. Consuming pure sodium chloride strains the body, upsetting fluid balance and dehydrating cells.

Unrefined sea salt is 82 to 84 percent sodium chloride, and the rest is other good stuff: calcium, magnesium (about 14 percent), and more than eighty trace elements including iodine, pota.s.sium, and selenium. These nutrients have vital functions, among them maintaining a healthy fluid balance and replenis.h.i.+ng electrolytes lost in sweat. We need trace elements in tiny amounts, but a deficiency is serious. The landlocked American Midwest, for example, was known as the "goiter belt" for lack of iodine-rich seafoods. Today commercial salt contains added iodine to prevent thyroid disease, but the body absorbs natural iodine in unrefined salt more easily.

How much salt do you need? That depends on many things, including your size and genes and how much you sweat. As with fat (and carbohydrates and the rest), I don't count sodium milligrams, and I have no idea how much pota.s.sium a head of lettuce contains, but I know that eating a lot of fruits and vegetables is a good thing. I also know when I've eaten too much salt, just as sure as I know when I've put too much olive oil on the salad. The main clue? I'm thirsty.

The body needs a balance of the two main electrolytes, sodium and pota.s.sium. Whole foods contain little sodium and plenty of pota.s.sium, but the typical industrial diet is the opposite: it contains too much sodium and too little pota.s.sium. Do avoid sodium-rich industrial foods, including prepared meals, savory snacks, bouillon cubes, and commercial chicken stock. According to the National Academy of Sciences, processed food- not the salt cellar- accounts for 80 percent of the salt in the typical diet. When I do buy canned goods such as tomatoes and chickpeas, I look for unsalted versions, or I rinse the beans and add real salt to taste during cooking.

If you avoid industrial foods, exercise, eat fresh fruits and vegetables daily, and drink plenty of water, there is no need to fear traditional salt. In the kitchen and at the table, I'm liberal with unrefined salt. But remember: if you want the benefits of all the vital trace elements of the sea, the label should say unrefined. Salt sold simply as "sea salt" is refined in some way, no matter how charming and rustic the packaging. And yes, unrefined sea salt is more expensive than the rest. It's worth more.