How I Stopped Worrying and Learned to Love Saturated Fats.

AT BONNIE SLOTNICK'S, a wonderful Greenwich Village bookshop, I was hunting for clues to the traditional American diet as if they were pottery shards, when Bonnie showed me Twenty Lessons in Domestic Science, a slim book billed as a "condensed home study course." It sold for two dollars in 1916, but I was happy to pay fourteen dollars. Twenty Lessons presents the food groups, nutritional information, recipes, and "Hints for the Housewife." "Make a business of your kitchen," it says, "and run that business as carefully as does the merchant who sells you your food." Very sensible.

All-but-forgotten frugality is not what I find curious about old nutritional primers. They ill.u.s.trate just how dramatically the American diet has changed and how fast. In Lesson No. 1: The Composition of Food Materials, a government "Expert in Charge of Nutritional Investigations" at the U.S. Department of Agriculture provides nutritional information on meat, dairy, fish, grains, and other foods. It was the sketch of fats and oils that stood out; only five were mentioned: bacon, lard, beef suet, b.u.t.ter, and olive oil. In 1916, these were the fats we ate. Not anymore.

A child of my times, I once steered clear of saturated fats. Most people, and most doctors, would have regarded my diet and habits as stellar. In those days, I ate a lot of fish, vegetables, and olive oil; I was a runner and got plenty of sleep. But my digestion was poor, and I was often laid low by colds and the flu. Today my complaints are gone, I rarely get sick, and I feel great. The only change is eating saturated fats every day.

Perhaps you're like me a few years ago, and you've never heard a good word about "artery-clogging" saturated fats. Actually, they are vital to health. The most basic function of saturated fats is structural: they make up half of cell membranes. The site of all chemical activity in the body, the cell is a barrier to unwanted substances and a gateway to good ones, and the cell membrane is an extremely fine tool. A human hair is eighty thousand nanometers wide. (One million nanometers make a millimeter.) By comparison, the cell wall is tiny: only ten nanometers thick. It needs exactly the right degree of flexibility and permeability: neither too stiff nor too floppy, neither impenetrable nor too porous. Saturated fats provide stiffness, unsaturated fats flexibility.

Certain saturated fats (short- and medium-chain fatty acids) are easy to digest because they do not have to be emulsified first by bile acids, as long-chain polyunsaturated fats do. These saturated fats (in b.u.t.ter and coconut oil) are used directly for energy, rather than stored as fat. Saturated lauric acid in coconut oil actually increases metabolism.

Saturated fats are required for the absorption of calcium and other minerals. When the diet contains saturated fats, the body is better able to retain the vital long-chain polyunsaturated fats, such as the omega-3 fats in fish.4 Saturated fats also build immunity by fighting harmful microbes, viruses, and other pathogens, especially in the digestive tract. Saturated lauric acid destroys the HIV virus.

Maybe you aren't convinced. Saturated fats may fight infections, but what about heart disease? Here again, I found surprises. Saturated fats lower blood levels of lipoprotein (a) (Lp(a)), which leads to clotting and atherosclerosis. Even the fats around the heart muscle are saturated.5 They include stearic acid, found in beef and chocolate, and palmitic acid, in coconut oil, palm oil, and b.u.t.ter.6 What about the "fatty" plaques in arteries that can burst and cause heart attacks? Fat is only one part, often a small one, of such plaques.7. Moreover, only 26 percent of the fat in arterial plaques is saturated.8 The rest is unsaturated, of which more than half is polyunsaturated.

The cholesterol theory says that eating saturated fats raises blood cholesterol in unhealthy ways. The truth is more complicated. First, about half of blood cholesterol has nothing to do with diet. Second, when you eat too much saturated fat, the body converts it to monounsaturated fat, which lowers LDL and leaves HDL alone.9 Furthermore, certain saturated fats (palmitic and stearic acid) have a neutral or beneficial effect on cholesterol. Forgive me for mentioning stearic acid again; perhaps I've grown partial to it because I'm fond of chocolate, but it kept turning up in my reading. Stearic acid makes a curious case study in the history of fats.

Ancel Keys, an early proponent of the cholesterol theory, made the Mediterranean diet, featuring fish, vegetables, olive oil, and REAL FATS 177 red wine, famous in the 1950s and '60s. Keys developed predictive equations on diet and cholesterol. Most of his calculations, which were influential, showed that saturated fat raised cholesterol more than polyunsaturated fat, as he expected. Keys also found that stearic acid did not raise cholesterol, a detail he ignored. Later, other research confirmed the neutral or positive effect of stearic acid on blood cholesterol, especially the ratio of HDL to LDL. The National Research Council's report Diet and Health and the surgeon general's Report on Nutrition and Health both noted that stearic acid did not raise cholesterol. In 2005, the journal Lipids wrote: "Stearic acid lowers LDL cholesterol."10 Once the facts were in on stearic acid, did the experts tell us that the saturated fat in beef and chocolate were good for the heart? No. According to the International Food Information Council, "In light of the findings about stearic acid, some researchers recommend no longer grouping it with other saturated fats."11 In other words, they proposed to redefine saturated fats rather than admit that some saturated fats don't raise cholesterol.

Diabetes is a risk factor for heart disease, and for some time, diabetics were prescribed a low-fat, high-carbohydrate diet of fruit, bread, pasta, and nonfat dairy foods. Now (sensibly) there is more emphasis on protein, but saturated fats are still taboo. The American Diabetes a.s.sociation says that monounsaturated fats are best, polyunsaturated oils second-best, and saturated fats to be avoided.

Dr. Diana Schwarzbein, whose specialty is endocrine and metabolic diseases, disagrees. She found that type 2 diabetics got worse on a low-fat, high-carbohydrate diet. Faithful to her dietary prescriptions, her patients gained weight, their cholesterol rose, and they required more insulin, not less. Frustrated, Schwarzbein decided to experiment. When she added a little fat and protein to the menu, results were excellent. Her patients lost weight and had more energy. Their blood sugar and cholesterol fell. To her surprise, the best results were in the patients who " cheated"- they ate saturated fats and cholesterol in "real mayonnaise, real cheese, real eggs, and steak every day," she writes. In The Schwarzbein Principle, she describes "The Myth of Saturated Fat": "Many studies . . . vilify saturated fats . . . My clinical experience with thousands of people has shown that eating saturated fats is not the culprit! On the contrary . . . patients who have increased consumption of saturated fats (as well as all other good fats) have improved their cholesterol profiles, decreased blood pressure, and lost body fat, thereby reducing their risk of heart disease."

My own (admittedly unscientific) experience has helped convince me that saturated fats don't cause unhealthy cholesterol. As I learned more, I conducted a tiny, unintentional experiment. Gradually, I ate more saturated fat in foods like cream, chocolate, and coconut, until I was eating them every day- as I still do. After eating this way for several years, my cholesterol, HDL, LDL, triglycerides, and other signs of cardiovascular health are off-the-charts healthy by the standards of the National Cholesterol Education Program. Indeed, the more saturated fat I eat, the better the numbers look. Yet, by the logic of the cholesterol theory, I'm doing some important things wrong, and some part of me expects the numbers to look worse. But they never do.

The story is- of course- not so simple. I also do other things the experts call heart-healthy: I exercise, I don't smoke, and I eat more than my share of fruit, vegetables, olive oil, fish, dark chocolate, walnuts, and wine. I don't eat trans fats or refined vegetable oils, and I steer clear of sugar and white flour.

Mine is a balanced diet, to be sure, and the reader (or cardiologist) who favors moderation in all things might consider moderation its chief virtue. Perhaps. But I routinely eat more saturated fat than experts advise. They would not recommend eating two eggs with b.u.t.ter for breakfast, coconut curry for lunch, and cream in my cocoa. The medical literature has a label for people like me: exceptions to the rule. If saturated fats raise cholesterol, and I eat saturated fats but my cholesterol is fine, I am a "nonresponder." Or it could be that the rule is flawed.

Advice on fats is evolving. In 2004, the American Journal of Clinical Nutrition published a striking article. The authors called our understanding of saturated fats in particular "fragmented and biased" because research on fats had been so limited. "The approach of many mainstream investigators . . . has been narrowly focused to produce and evaluate evidence in support of the hypothesis that dietary saturated fat elevates LDL," the authors wrote. "The evidence is not strong."12 They noted that saturated fats were "disappearing" from the food supply and asked, "Should the steps to decrease saturated fats to as low as agriculturally possible not wait until evidence clearly indicates which amounts and types of saturated fats are optimal?"13 Accustomed as we are to hyped headlines about miracle foods and superdrugs, this query about fats may seem innocent. Hardly. Go back and read that paragraph again. Given the conservative style of scientific literature and the heft of the conventional wisdom against saturated fats, for a prestigious journal to comment in this way is radical.

One year later, as if to answer the call for more research, along came a study of twenty-eight thousand middle-aged men and women in Malmo, Sweden.14 Researchers looked for links between fats and mortality from heart disease and from all causes. "No deteriorating effects of high saturated fat intake were observed for either s.e.x for any cause of death," they wrote. "Current dietary guidelines concerning fat intake are thus not supported by our observational results."

How much evidence do you need? That's up to you. But if you still fear that traditional saturated fats are trouble, my hunch is that in the next few years, more evidence in favor of b.u.t.ter will come your way.

Please b.u.t.ter Your Carrots.

IN FASHION TERMS, fats are like a string of pearls- they go with everything. The modern habit of eating chicken b.r.e.a.s.t.s and other lean cuts trimmed of all offending fat is new, an aberration in three million years of human history. Most people never ate protein without fat for the simple reason that in nature, protein and fat go together. In animals, fat and muscle are attached.

Eating the fat along with the protein is also frugal and efficient. Traditionally, hunters and farmers ate the whole animal, including the skin, extra fatty bits, bone marrow, brain, and rich organ meats. Contemporary human hunters, like carnivores, go for the organs and fatty parts first. Moreover, when times are good- that is, when there is plenty of food- hunters may even leave the muscle behind for scavengers. Vitamins and other nutrients in the fats and organs are simply more valuable than the lean protein.

Above all, eating protein with fat makes nutritional sense, because all food, and protein in particular, requires fat for proper digestion. As we saw earlier with "rabbit starvation," without fat in the diet, digestion fails and you starve, but not for lack of calories.

What is true of meat is true of all fat-and-protein pairs: they go together. Consider, for example, two near-perfect foods: eggs and milk. Both foods are a complete nutritional package, designed for a growing organism's exclusive nutrition, and must contain everything the body needs to a.s.similate the nutrients they contain. Thus the fats in the egg yolk aid digestion of the protein in the white, and lecithin in the yolk aids metabolism of its cholesterol. The b.u.t.terfat in milk facilitates protein digestion, and saturated fat in particular is required to absorb the calcium. Calcium, in turn, requires vitamins A and D to be properly a.s.similated, and they are found only in the b.u.t.terfat. Finally, vitamin A is required for production of bile salts that enable the body to digest protein. Without the b.u.t.terfat, then, you don't get the best of the protein, fat-soluble vitamins, or calcium from milk. That's why I don't eat, and cannot recommend, egg white omelets and skim milk. They are low-quality, incomplete foods.

FATS GO WITH EVERYTHING.

In each cla.s.sic pair, fats help the body a.s.similate, use, or convert essential nutrients.

Fat and Protein Roast chicken (with the skin) Eggs (with the yolks) Fat and Vitamins Vitamins A, D, E, and K are fat-soluble; eat them with fat Fat and Beta-Carotene.

b.u.t.tered carrots.

Collards with fatback.

Spinach salad with bacon.

Flank steak with arugula.

Beef with broccoli.

Saturated Fat and Omega-3 Fats.

Fish with b.u.t.ter or cream sauce.

Saturated Fat and Calcium.

Whole milk.

Yogurt, cheese, and sour cream made from whole milk.

Without fats, even vegetables are less nutritious. Brightly colored vegetables are rich in antioxidant carotenoids. They go better with b.u.t.ter. In 2004, Iowa State University researchers who compared people eating salads with traditional or fat-free dressings found those shunning fat failed to absorb lycopene and beta-carotene, powerful antioxidants that boost immunity and fight cancer and heart disease. "Fat is necessary for the carotenoids to reach the absorptive intestinal walls," said the lead researcher, Wendy White. Lycopene is found in tomatoes and beta-carotene in orange, yellow, and green vegetables.

For vegans, who must rely entirely on vegetables for vitamin A, dressing salad with a traditional fat is even more critical. Recall that true vitamin A is found only in animal foods ( especially b.u.t.ter, eggs, fish, and liver). The body can make its own vitamin A from the beta-carotene in carrots, but the conversion is costly (it requires fats and bile salts made from cholesterol) and uncertain. Babies, children, diabetics, and those with thyroid disorders make vitamin A with difficulty. Thus a person eating a strict vegan diet risks vitamin A deficiency. As Hindus and other traditional vegetarian groups know, b.u.t.ter and eggs are vital ingredients in vegetarian cooking.

Last but not least, the chemistry of fats can explain the long tradition of serving fish with b.u.t.ter and cream. Saturated fats are required to a.s.similate omega-3 fats, and they make omega-3 fats go farther in the body. That's the solid nutritional logic behind the delicious combinations of lobster with melted b.u.t.ter and Dover sole with b.u.t.ter sauce.

Make Mine Extra-Virgin.

IN 1971, AN ITALIAN INTERNIST in her seventies named Mary Catalano was the only doctor in Buffalo who would deliver babies at home. At my mother's final prenatal checkup, Dr. Catalano, who specialized in heart disease, had an unusual question: was there olive oil at the house? The answer was yes. So, right after I was born, the doctor gently wiped my skin with olive oil. Now I wish we could ask her why. Olive oil is often used in homemade cosmetics, but I like to think of my rubdown as part of some long-lost midwifery tradition. Why not credit Dr. Catalano with my love of olive oil?

The queen of vegetable oils, olive oil is the most famous fat in the world, with a long, glorious history in cuisine and special status in many cultures. Olive oil is one of the first foods Italian babies eat, and one of the last foods offered to the dying. The evergreen olive tree grows all over the world, from Tunisia to California to Australia, and can still bear fruit at the grand age of one thousand years. Olive oil is a staple food in Greece, Italy, Portugal, and Spain, where most of the world's olive oil is produced. Its flavor is complex and varied- sometimes gra.s.sy and peppery, sometimes b.u.t.tery and smooth.

Olive oil is also very good for you. It is rich in vitamin E and other powerful antioxidants called polyphenols; both nutrients prevent heart disease and cancer. By preventing oxidation, they also keep the oil itself fresh. Olive oil inhibits platelet stickiness, lowers blood pressure, and reduces inflammation. Olive oil has a good reputation with cardiologists because it is 70 percent monounsaturated oleic acid, which lowers LDL.

Olive oil is about 14 percent saturated palmitic acid (also found in palm oil, b.u.t.ter, and beef), which has a neutral or beneficial effect on cholesterol.15 Palmitic acid lowers LDL.16 Olive oil also contains about 10 percent LA, the essential omega-6 fat. But you probably don't need more LA; the industrial diet contains too much LA from vegetable oils. If you eat corn, safflower, or soybean oil, replace them with olive oil, which contains plenty of LA.

OLEIC ACID IN OLIVE OIL AND ANIMAL FATS.

Healthy, delicious, and versatile in the kitchen, olive oil has never fallen out of culinary favor. It is often used cold in vinaigrettes, pesto, and other raw sauces, which protects its delicate vitamins and antioxidants, but it is also suitable for cooking at moderate temperatures because it's about 85 percent monounsaturated and saturated. Many "heart-healthy" recipes call for polyunsaturated vegetable oils such as corn or grapeseed oil for sauteeing, but olive oil is a better choice. According to Lancet Oncology, "The high content of the monounsaturated fat, oleic acid, is important because it is far less susceptible to oxidation than the polyunsaturated fat, linoleic acid, which predominates in sunflower oil" and other vegetable oils from grains and seeds.17 A blend of b.u.t.ter and olive oil is even more heat stable because of the b.u.t.ter's saturated fats.

Unlike other vegetable oils, olive oil requires little processing- and for nutrition and flavor, the less the better.18 Olive oil comes in three grades: plain, virgin, and extra-virgin. Virgin and extra-virgin oils are made in the traditional way with minimal damage to the fruit, which are simply crushed between stones without heat or chemicals. Though labor-intensive, handpicking and cold-pressing preserve delicate vitamin E and antioxidant polyphenols. According to the definition of the International Olive Oil Council, extra-virgin oil comes from the first pressing of the fruit, has no defects in taste or smell, and has acidity of 1 percent or less. Many producers have even higher standards for acidity. When olives are handpicked and cold-pressed the same day, for example, acidity is lower. The best olive oil is unfiltered to retain all its nutrients and flavor (it will be cloudy) and bottled in dark gla.s.s to shield it from oxidizing light.

Most commercial olive oil is the lowest grade- plain. It is usually labeled olive oil, or sometimes, confusingly, pure or 100 percent pure olive oil. For this grade, the olives are picked by machine, which tends to bruise them. Bruised olives ferment and oxidize, which raises acidity and produces inferior oil.19 The olives are pressed repeatedly with heat and subjected to chemical extraction, which diminishes nutrients and flavor. The base of plain olive oil is "lampante oil," so-called because it was once burned in lamps. Almost inedible in its crude state, it is either rancid or too acidic and must be refined to make it fit to eat. Treatments include acid washing, degumming, bleaching, and deodorization to remove foul odors.20 The refined lampante oil is blended with virgin oil to make plain olive oil palatable.

The more olive oil is refined, the less vitamin E and antioxidants it has, and you can measure the difference: extra-virgin oil has significantly more polyphenols than lesser grades.21 More polyphenols means better flavor and more health benefits. "High consumption of extra virgin olive oils, which are particularly rich in these phenolic antioxidants . . . should afford considerable protection against cancer (colon, breast, skin), coronary heart disease, and ageing by inhibiting oxidative stress," say antioxidant experts.22, Women who eat olive oil (and fruits and vegetables) significantly reduce the risk of breast cancer, while eating margarine increases it.23 How, exactly, does olive oil fight heart disease and cancer? Oxidized LDL is a cause of heart disease. Polyphenols inhibit oxidation of LDL, and the more the better.24 Polyphenols may also stimulate antioxidant enzymes and increase HDL. Another antioxidant in extra-virgin oil, squalene, fights skin cancer. Still other antioxidants called lignans inhibit cell growth in cancers of the skin, breast, colon, and lung.

To reap all the flavor and health benefits of olive oil, buy the best oil you can afford, ideally extra-virgin, cold-pressed, and organic. I use extra-virgin oil, even for cooking. When you heat extra-virgin oil, antioxidants counter the damage to the delicate vitamin E and unsaturated fats. If that's too expensive, use virgin oil for frying and extra-virgin for cold dressings. Beware of "light" olive oil. It's a marketing gimmick to make you think it has fewer calories. Refined to remove color and scent, it lacks the flavor and antioxidants of extra-virgin oil. Store olive oil away from heat and light.

Most olive oils, including better-quality brands, are blends of different crops, to ensure consistent flavor and quality, not unlike wine blended from different grape harvests. The very best olive oils, again like wines, are estate bottled, which typically means the olives from one harvest were pressed and bottled where they were grown. Fancy estate oils are often seasonal and usually quite delicious. But for me, at least, they're a rare treat. I use a lot of olive oil, so I watch my budget.

My Opinion of the Minor Vegetable Oils.

WHAT OIL is BEST FOR SAUTEING? When I talk with people about fats, this is one of the most common questions they ask me. The short answer: not polyunsaturated vegetable oils such as corn, safflower, sunflower, and soybean oil. Those fats are too delicate. When heated, they oxidize and become rancid and carcinogenic. The best cooking fats are mostly saturated, such as b.u.t.ter, beef, and coconut oil. Second best are the mostly monounsaturated fats, such as lard, macadamia nut oil, and olive oil.

These answers, unfortunately, don't satisfy most people. They might regard olive oil as too expensive for everyday cooking. Often they're looking for a "neutral" flavor. The bland taste of lard makes it a great platform for flavors sweet and savory- one reason it's perfect for pie crust. However, it seems that many people are not ready to start frying chicken in lard, even though good cooks all over the world do just that. Olive oil, b.u.t.ter, and coconut oil do have p.r.o.nounced flavors. I love the scent, flavor, and feel of coconut oil, but usually I save it for certain dishes like Sri Lankan fish curry. Coconut oil does not flatter asparagus or new potatoes.

The goal of a "neutral" flavor is tricky anyway- perhaps even futile. Fats, more than any other food, are aromatic. They not only have flavor but also carry flavors on the palate. Having tasted many fats, I've concluded there is no such thing as a flavorless fat. b.u.t.ter tastes like cream, olive oil like olives, corn oil like corn. That's why many oils (including avocado, olive, corn, and coconut) are refined, bleached, or deodorized- to strip them of scent and flavor. The result is a bland fat, to be sure, but with unhappy results, in every case, for the nutrients in the natural version.

It may be best to forget the quest for a "neutral" flavor. Fats are a.s.sertive; for that reason they lend character to whole cuisines. Middle Eastern dishes call for frying many foods in lamb fat. Most Americans would call that a very strong flavor; lamb colors all the dishes, in the same way olive oil leaves its mark on the cuisine of Greece, where even desserts are made with the herbaceous oil. We may regard olive oil as somehow more neutral tasting than lamb fat, so redolent of lanolin, but that's merely a matter of taste and familiarity.

My advice is to treat fats as you would any other ingredient: choose the feel and the flavor to match the dish. As I've mentioned, I mostly use b.u.t.ter and olive oil, or a combination, for sauteing and roasting. For certain dishes, like roasted red peppers, I use only olive oil, and I simply don't worry about the few polyunsaturated fats it contains. But it is true that heating any unsaturated oil is less than ideal. Sometimes I blanch or steam vegetables and add the olive oil after cooking, which has the added virtue of showcasing the flavor of relatively expensive extra-virgin oil.

Even after I confess to heating olive oil and reveal my ( unoriginal) olive oil-and-b.u.t.ter blend secret, people still want to know about neutral vegetable oils for sauteing, frying, and dressing salads. There are many culinary vegetable and nut oils, from Brazil nut to grapeseed to pecan; you will have to find your favorites. (See the accompanying sidebar for a few vegetable oils I might use- or wouldn't disapprove of, anyway- other than olive and coconut oil.) A FEW OTHER VEGETABLE OILS.

Acceptable for Cooking * Macadamia nut oil is about 85 percent monounsaturated, which makes it suitable for cooking, though I prefer it cold. b.u.t.tery and nutty, it has a lovely flavor, but it's not cheap.

* Peanut oil is 46 percent monounsaturated oleic acid, 31 percent polyunsaturated LA, and about 17 percent saturated. Because it's about 60 percent monounsaturated and saturated, it's fine for cooking, if the flavor suits you. Don't buy hydrogenated oil.

* Sesame oil is 43 percent polyunsaturated LA, 41 percent monounsaturated, and 15 percent saturated. It's suitable for cooking, but the flavor is hardly neutral, especially toasted oil. Its unique antioxidants, including sesamin, are not destroyed by heat like most antioxidants; they protect the polyunsaturated fats. In Chinese cooking, sesame oil is typically used cold in salads or added after cooking.

Best Used Cold.

* Flaxseed oil comes from linseed. Ground flaxseed has been a traditional food and medicine in the Mediterranean region and Africa for thousands of years. It's the best plant source of omega-3 ALA (60 percent), which the body uses to make DHA and EPA. Flaxseed oil has a distinctive herbaceous, woody flavor. A blend of flaxseed and olive oil in vinaigrette is a good way to slip omega-3 fats to vegetarians and people who don't eat enough fish. ALA is very sensitive to light and heat. Keep flaxseed oil in the fridge.

* Grapeseed oil is about 70 percent polyunsaturated LA and rich in heat-sensitive vitamin E, which makes it a poor frying fat. I don't use it, mostly because it's so rich in omega-6 fats, but people like it for its neutral flavor.

* Walnut oil is about 54 percent polyunsaturated LA. It also contains about 12 percent omega-3 ALA. Highly unsaturated, walnut oil should be cold-pressed, kept cold, and used cold. It has a p.r.o.nounced, tannic flavor I happen to love, and I use it often in salad dressing, sometimes with roasted walnuts.

What about the common vegetable oils grown in the American heartland, including corn, safflower, sunflower, and soybean oil? I don't use, or recommend, any of the modern vegetable oils. They're rich in polyunsaturated omega-6 LA (too delicate for heat), and most Americans eat far too many omega-6 fats already. They also lower HDL. Fran McCullough has a sensible take on high-oleic acid sunflower oil in Good Fat: "If you desperately need a flavorless oil that's not light [refined] olive oil, this is your best candidate, as long as it's expeller-pressed (cold-pressed, without high heat), not hydrogenated, and stored carefully. Still, this is a fragile oil with no particular health benefits beyond its high-oleic additive.25 Other vegetable oils mentioned here- sesame, peanut, and grapeseed- are also fairly rich in omega-6 LA. That's one reason I seldom use them, but I also prefer other oils. If you don't eat corn, safflower, sunflower, or soybean oil, a little sesame or peanut oil, if that's what you prefer for a broccoli stir-fry, won't do any harm.

Coconut Oil Is Good for You.

IN THE NINETEENTH CENTURY, coconut oil was common in baked goods, from cookies to crackers. A saturated fat like coconut oil is ideal for baking because it's stable when heated, remains solid at room temperature (which makes things flaky), and has a long shelf life. Cookie companies and home bakers alike used it. An 1896 ad for "pure and wholesome cocoanut b.u.t.ter" recommended it in place of lard and b.u.t.ter and boasted endors.e.m.e.nts from chefs and doctors.

By the middle of the twentieth century, coconut had all but disappeared from the American diet. What happened? It was a commercial battle over what fat would be used in baked goods, and the compet.i.tors were domestic vegetable oils and imported tropical oils, including palm and coconut oil. As the two industries fought for market share, nutrition experts threw the knockout punch: the idea that saturated fats cause heart disease. Coconut oil imports never recovered.

Today, most commercial baked goods are made with another solid and shelf-stable fat: hydrogenated vegetable oil. That turned out badly; now we know that trans fats cause heart disease. Meanwhile, coconut oil turns out to be innocent of the cholesterol charges, with other virtues in the bargain.

The coconut palm tree grows in the tropics and subtropics, including Asia, India, Africa, and Latin America, where the milk, flesh, and oil of the coconut fruit are used in a variety of dishes, from drinks to soups and sauces. Coconut flesh contains fiber, fat, vitamins B, C, and E, and calcium, magnesium, iron, zinc, and pota.s.sium. Coconut oil is a folk remedy in many cultures, from the Philippines to Sri Lanka. Polynesians, who eat coconut and coconut oil every day, call it the "Tree of Life."

Like all saturated fats, coconut oil is solid at room temperature; it turns soft at about seventy-six degrees Fahrenheit. The oil is rich (64 percent) in medium-chain saturated fatty acids, which have unusual properties. The main fat (49 percent) is lauric acid, an antimicrobial, antifungal, and antiviral fatty acid all but unique to coconut oil and breast milk. Lauric acid kills fat-coated viruses, including HIV, measles, herpes, influenza, leukemia, hepat.i.tis C, Epstein-Barr, and bacteria, such as Listeria, Helicobacter pylori, and strep.26 Monolaurin, an agent the body makes from lauric acid, fights the herpes and cytomegalovirus viruses.27 The medium-chain fats in coconut oil don't need to be emulsified by bile acids before they are digested, as long-chain polyunsaturated fats do. Thus the body burns coconut oil more quickly than long-chain polyunsaturated fats like soybean oil, which it tends to store for later. For this reason, lauric acid is easy to digest, and for decades doctors have fed coconut oil to patients unable to digest polyunsaturated fats.28 Medium-chain fats can also aid weight loss. Ultimately, of course, the most important thing is how much energy you consume and spend, but metabolism is more subtle than that. For example, lean protein has a higher "thermic effect" than fat or carbohydrate; that means it gives metabolism a boost. Lauric acid has a similar effect. A large number of studies in both animals and people show that coconut oil, when compared with polyunsaturated fats, enhances weight loss.29 What about heart disease? In the 1960s, Dr. Ian Prior, director of epidemiology at Wellington Hospital in New Zealand, studied all twenty-five hundred people on the South Pacific islands Pukapuka and Tokelau. Coconut was the bulk of the diet, appearing at every meal as a drink, vegetable, dessert, or cooking oil. They ate pork, poultry, seafood, and produce, too, but the striking thing about their diet is the large amount of fat and saturated fat. On Tokelau, 57 percent of calories came from fat, about half of it saturated. On Pukapuka, they ate sixty-three grams of saturated fat daily and seven grams of unsaturated fat. Yet all the islanders were lean and healthy, with no signs of unhealthy cholesterol, atherosclerosis, or heart disease.

Then, by chance, nature presented an experiment. When crop failure forced Tokelau islanders to move to New Zealand, they ate less coconut oil, less fat, half as much saturated fat, and more polyunsaturated oils than at home. Good for the heart, right? But in 1981, Prior found his subjects living in New Zealand in worse health: the immigrants had higher cholesterol, higher LDL, and lower HDL.30 "The more an Islander takes on the ways of the West, the more p.r.o.ne he is to succ.u.mb to our degenerative diseases," Prior said.

In the last thirty years, a number of studies have cleared coconut oil of any role in heart disease, and recent research confirms those findings.31 In 2002, researchers fed people seventy to eighty grams of medium-chain fats or vegetable oils daily and found no differences in total cholesterol, VLDL, LDL, or HDL, or triglycerides.32 Other researchers who fed medium-chain fats to rats stated bluntly, "The lipid [fats] theory of arteriosclerosis is rejected." They noted that Sri Lanka, where coconut oil is the main fat, had low mortality from heart disease.33 Coconut oil even improves the all-important ratio of HDL and LDL.34 A study of Malaysians who ate palm, coconut, or corn oil for five weeks found that coconut oil increased HDL, improving the ratio.35 In the same study, saturated palmitic acid (found in another tropical fat, palm oil) lowered total cholesterol and LDL.

How, then, did coconut oil get a bad reputation? Partly because we misunderstood cholesterol. We used to think that any fat that raised total cholesterol, as coconut oil can, was unhealthy, but now we know that total cholesterol is a poor predictor of heart disease and that raising HDL is good. Moreover, hydrogenated coconut oil was used in some studies. In 1996, the lipids expert Mary Enig explained that hydrogenation raises cholesterol: "Problems for coconut oil started four decades ago when researchers fed animals hydrogenated coconut oil purposefully altered to make it devoid of essential fatty acids. Animals fed hydrogenated coconut oil (as the only fat) became essential fatty acid-deficient; their cholesterol levels increased. Diets that cause an essential fatty acid deficiency always produce an increase in cholesterol."36 In 2001, researchers reported that partially hydrogenated soybean oil was worse than coconut oil. "Epidemiological and experimental studies suggest that trans fatty acids increase risk more than do saturates because [trans fats] lower HDL," they wrote. "Solid fats rich in lauric acids, such as tropical fats, appear to be preferable to trans fats in food manufacturing, where hard fats are indispensable."37 Big food companies may not be rushing to put coconut oil back in crackers, but you can put fresh coconut, dried flakes, and coconut milk, cream, and oil in cookies, soups and curries. Many people take a spoonful of coconut oil daily to aid weight loss and boost immunity.

Coconut oil comes in three unofficial grades. The best is unrefined or virgin oil, made by shredding and cold-pressing coconut flesh while it is moist, a process called wet milling. The meat, milk, and oil are fermented for at least twenty-four hours while the water and oil separate. Finally, the oil is gently heated to remove moisture and filtered. Virgin oil has the lovely flavor and scent of coconut.

The second-best coconut oil is expeller-pressed and gently deodorized to remove scent and flavor; it's a good choice if you eat coconut oil for health but don't care for the flavor. Industrial coconut oil is made by extracting oil from copra, or dry coconut meat. To make it edible, the oil is refined, bleached, and deodorized, which destroys vitamins, scent, and flavor.

I buy virgin coconut oil and cream, along with wonderful soap and moisturizer, from a cooperative of small growers in the Philippines called Tropical Traditions. You can also find good brands of virgin coconut oil in whole foods shops, good groceries, and Asian shops. Virgin coconut oil isn't cheap, but I don't use it every day, a little goes a long way, and it keeps for two years without refrigeration. Canned coconut milk is less expensive. I like to have a couple of cans in the cupboard for making a simple, creamy soup made of equal parts chicken stock and coconut milk, with sauteed ginger and cayenne. Everyone loves it.

7.

Industrial Fats.

How the Margarine Makers Outfoxed the Dairy Farmers.

THE ADVICE TO REPLACE b.u.t.tER with margarine containing trans fats const.i.tuted a radical dietary experiment. Trans fats are created when oil is hydrogenated. That's when unsaturated oil is blasted with hydrogen atoms, a form of artificial saturation that makes the liquid oil solid, like natural saturated fats. But the similarity between trans fats and traditional saturated fats ends there. Trans fats are new and dangerous. Traditional diets contain healthy saturated fats from both plants (like coconut) and animals (b.u.t.ter), but until the twentieth century, no one ate trans fats, and now we know they cause heart disease.1 Hydrogenated vegetable oils are widely used in cakes, cookies, donuts, chips, and crackers, for the same reason food companies once used coconut oil: they're solid, heat-stable, and don't spoil easily. Though it's possible to hydrogenate any fat that is not fully saturated (such as lard, which is about 60 percent unsaturated), most hydrogenated oils are made from polyunsaturated vegetable oils such as canola, corn, and soybean. In a moment we'll come back to trans fats, but first, let's look at margarine, the mother of hydrogenated oils.