12/14/2004 6:12pm, #1
Granted, Peedee is too busy working out to read this; but even if he did, it makes far too much sense, and accounts for the paradoxes he's unwilling to confront.
Everyone I know who read Gary Taubes’s article in the New York Times Magazine, “What if Fat Doesn’t Make You Fat,”1 had the same reaction. They splurged on high-fat, forbidden foods like bacon sandwiches and ice cream for a day or two before coming to their dietary senses. Then they went back to eating what they had always eaten, but with a small, significant difference: they now felt slightly more friendly, slightly more welcoming, towards those old bugaboos. People who had shied away from high-protein diets like the Atkins Diet (high-fat diets, really, since it’s impossible to consume a high-protein diet without becoming very ill) because of health considerations were encouraged by Taubes’s seemingly reasonable and exhaustive article to give them a try.
Health and medical organizations reacted quickly to Taubes’s piece, coming down fast and hard on the idea that carbs, not fats, are to blame for the epidemic of obesity today, but the public had already slurped up the information, like milkshake through a straw. People were primed— hungry, one might say—to make this shift. And those same health and medical organizations are partly to blame.
When the American Heart Association endorses Cocoa Puffs and Lucky Charms (breakfast cereals that have no saturated fat but are loaded with simple sugars, “empty calories” as they are often called), when the United States Department of Agriculture fails to distinguish between refined and unrefined carbohydrates and fails to encourage the consumption of such healthy fats as the oleic acid in olive oil and the omega-3 polyunsaturated fats in fatty fish and leafy greens in its Food Guide Pyramid, they prepare the ground for articles like Taubes’s. These endorsements and recommendations are hopelessly out of step with research showing that complex carbohydrates—whole-grain products in which the starch is still associated with natural fiber—are absorbed more slowly and cause a slower return of hunger after meals than the refined carbohydrates and simple sugars that make up a large portion of the American diet. They ignore studies indicating that one family of polyunsaturated fats protects against weight gain and heart disease, while the other may actually promote both of these conditions. And in the growing cracks and confusion between these new findings and the antiquated advice, Taubes’s article bloomed and the Atkins Diet thrives.
Somewhere in his lengthy piece, Taubes makes the distinction between saturated and unsaturated fats, but the take-home message of his piece (or should I say the take-out message, since most of the fat consumed in this country is in the form of fast food) is that fat is not as bad for you as the medical establishment has led you to believe, not even the saturated fats in dairy products and meat. Fat consumption in this country has decreased since the 1980s, says Taubes, as the ranks of the obese have swollen. (In truth, only the percentage of fat calories has decreased because total caloric intake has increased.2) Nor is fat consumption a reliable predictor of coronary heart disease (chd), since prospective studies have failed to make an association between fat intake and heart disease, and intervention trials using fat modification have yielded inconsistent results.
All I can say is that the Finns must be choking on their rye crisp and coughing up their woolen sleeves. In the late 1960s, Finland had the highest mortality rate from chd in the world(3)—well over 700 deaths per 100,000 people in 1971—and the highest intake of saturated fats, from a diet rich in full-fat dairy products, sausages, and canned meats. The Finns had other risk factors for chd: they consumed a lot of salt in their diet, smoked like chimneys, and ate very few fruits and vegetables—foods that are known to be protective against heart and many other diseases— but their story is illustrative nonetheless. Variables cannot be isolated in real-life populations, as they can be in experimental settings, and the story of what happened in Finland is one of the most successful, real-life dietary interventions of all time.
In the early 1970s, the Finnish government and Department of Health set out to lower the incidence of chd in their country by changing the dietary risk factors: encouraging Finns to switch from lard and butter to unsaturated vegetable oils and from full-fat to low-fat dairy products, as well as to lower their salt intake and increase their consumption of fruits and vegetables. And by 1997, the mortality rate from chd had been cut in half, still a high rate by some countries’ standards (in Greece, for example, it was 176 deaths per 100,000 in 1997), but an astonishing achievement in such a short period of time. So try telling the Finns that the link between saturated fats and heart disease is weak.
The Finns do support the other half of Taubes’s argument, though: that fat doesn’t necessarily make you fat. Obesity was rarely a problem for the Finns even when fat constituted thirty-nine percent of their energy intake and saturated fats twenty-one percent, even in subsets of the population that derived almost half of their energy from fat. Lumberjacks in Finland lived in huts in the forest and worked with handsaws and in deep snows. Their job demanded an exceptionally high intake of calories and of fat, since fat is the most concentrated source of energy, supplying 9 calories/gram versus 4 for carbohydrates or protein. Studies have found that the typical lumberjack in the 1950s ate between 4500 and 5000 calories a day, much of that in the form of milk, butter, and pork.4 He was extremely lean and muscular despite this diet, but his risk of chd was extraordinarily high. In our weight-obsessed society, it’s easy to lose track of the fact that weight and health don’t always go hand in hand, but Finnish lumberjacks, felled in their forties and fifties from chd, never confounded the two.
“It’s very difficult to have a healthy diet with a high dairy-fat content,” concludes Leena Rasanen, a Finnish researcher at the University of Helsinki who is directing a long-term study on cardiovascular risk. “Physical activity can help to protect you against heart disease, but it’s not enough.”
The Finns are not the only population to provide the world with lessons about fat, lessons that we are sometimes slow to learn, lessons that we aren’t always taught for economic or political reasons and/or because the science is still unfolding.
The Japanese, for example, could teach us about the dangers of too lean a diet, but you won’t often hear this lesson openly discussed. Physicians seem to think that the American public can’t handle the idea that moderation is the key to fat intake (and everything else), so they prefer a consistent low-fat, low-cholesterol message to one that is closer to the truth. Until the 1960s, the Japanese had an extremely low fat intake, less than ten percent of total calories, and, not surprisingly, a very low rate of chd and cancers associated with fat consumption—cancers of the breast, prostate, and colon. However, they had a very high rate of stroke (still the leading cause of death among adults in Japan), and their rate of stomach cancer was so high that the incidence of all cancers in Japan was similar to that in the United States.5 This raised the question of whether a very low intake of fat and cholesterol over a lifetime also has adverse effects.
Japanese health is affected, of course, by a high salt intake (and, in positive ways, by a diet rich in vegetables, grains, and fresh fish). But consider this: as the Japanese have increased their consumption of fat and animal fat in the last forty years—a dietary change that has been paralleled by a rise in blood cholesterol—their rates of stroke and stomach cancer have fallen while their rates of heart disease and breast and colon cancer have risen. At this point in time, the Japanese have the lowest total from all these diseases combined—and the longest life expectancy of anywhere in the world. But whether they can hold on to that distinction depends in large part on the direction their diet takes. Will their consumption of meat and saturated fats continue to rise? Or will meat remain a small but healthful part of a diverse diet?
The Greeks seemed to be teaching us the difference between a diet rich in vegetable fats and one rich in animal fats, but, in fact, the lesson of Greece and other Mediterranean countries is more about the virtues of olive oil than vegetable fats in general. Populations in Greece consume some forty percent of their calories as fat, mostly olive oil, and they have a very low rate of virtually all cardiovascular diseases and all cancers, except liver cancer, which is largely viral in origin. The word “diet” comes from a Greek word meaning “way of living,” and the Greek diet—fresh foods prepared with olive oil—is truly that.
When the remarkable healthfulness of the Greek diet was first brought to the world’s attention by the influential Seven Countries Study in the 1960s, researchers leapt to the conclusion that any vegetable oil would confer the benefits of olive oil, and they began to recommend the widespread use of soybean, corn, and safflower oils—oils that were less expensive to produce than olive oil. It was a well-intentioned move, but these oils had never been part of any traditional diet. They were a new and untested food since their production required high-temperature extraction techniques that had only just become available.
And now a new generation of researchers suspects that many of these oils are as bad for your health as the saturated fats they were designed to replace (and not just because of the trans-fatty acids in hydrogenated vegetable oils, fats that everyone agrees are dangerous6). You’ve heard of the French paradox—the fact that the French consume more animal fat and cholesterol than Americans but have a lower rate of heart disease—but you probably have never heard of the Israeli paradox: the fact that Israelis consume fewer calories and much less animal fat than Americans but have a higher rate of obesity and very high rates of heart and circulatory diseases, as well as non-insulin-dependent diabetes.7 Researchers suggest that the explanation for this paradox is Israel’s high intake of omega-6, polyunsaturated fatty acids, one of two families of essential fatty acids and the predominant essential fat in soybean, safflower, and corn oils. I will come back to this paradox because of its immediate importance for American, as well as Israeli health. But first I want to introduce the second family of essential fatty acids—omega-3s—and the people who taught us about the health benefits of consuming a diet rich in these nutrients.
Early explorers were the first to notice that the Inuit—Eskimos, as they were called until the late twentieth century—rarely experience heart disease, despite the fact that their diet is heavy with fat. Researchers later verified that the Inuit have an extremely high intake of fat and of cholesterol, as high or higher than the typical American, and a very low rate of chd, a paradox that wasn’t resolved until the late 1970s when two Danish scientists led a twenty-team dogsled expedition to northern Greenland to solve the mystery.8
There, scientists Jorn Dyerberg and H.O. Bang analyzed the diets and the coronary mortality statistics of the two populations living in Greenland: the Inuits and the Danes. They found that the Danes, who had a high incidence of death from chd, ate a diet high in saturated fat and cholesterol from meat and dairy products, a diet similar to that eaten in their homeland and, of course, in nearby Finland. The Inuit, on the other hand, ate a lot of seal, whale, and fish, foods that are very low in saturated fats and very high in omega-3, polyunsaturated fats. These fats have since been found to have powerful anti-clotting and anti-inflammatory effects and to lower serum lipid levels; they’ve also been found to prevent potentially fatal rhythm disturbances in heart muscle. Studies in Japan, Holland, and the United States all indicate that deaths from coronary artery disease can be reduced by more than fifty percent by the consumption of just one to two fish meals a week.9
Therefore, one of the clearest lessons we have about fat comes from the Inuit people of the far north: that the omega-3 content of diet is a more important determinant of healthy hearts than either the animal fat or cholesterol content. Unfortunately, we’ve been slow to grasp this lesson: we still spend far too much time thinking about fat as a concentrated form of calories, and far too little time thinking about the critical role that fats play in nature—in plants and in animals. Many of us supplement our diets with fish oil or with a serving of fatty fish a week, but until we understand how omega-3s exert their potent, beneficial effects and where omega-3s actually come from, we’ll continue to be vulnerable to the kind of pendulum swings started by Taubes’s article.
Omega-3s don’t originate in fish, it may surprise some to learn. Fish, like other animals (including humans), can’t make either the omega-3 or the omega-6 fatty acids. They can make saturated fatty acids and monounsaturated fatty acids, and they can elongate omega-3s and omega-6s and introduce even more double bonds into their carbon chains. However, they can’t produce a fatty acid with a double bond near the omega (methyl) end of the chain, a feat that only plants can perform. Therefore, all the essential fatty acids originate in plants as either linoleic acid (la), an eighteen-carbon chain with two double bonds, one of which is in the omega-6 position, or linolenic acid (ala), an eighteen-carbon chain with three double bonds, one of which is in the omega-3 position. la is more abundant in the seeds of many grains and nuts, and in the oils from seeds and nuts. ala is more plentiful in the leaves of plants, where it plays a key role in photosynthesis.
Animals also earmark la and ala for special purposes. They prefer not to use these fats as a source of energy as they would ordinary saturated fats (the fats they can make themselves). Rather, they slowly and laboriously elongate them, adding even more double bonds and protecting those unstable double bonds with security forces of kamikaze-like antioxidants, compounds like vitamin E that will take the oxygen “hit” and leave the double bond unharmed. They then use these highly unsaturated molecules as the starting material for hormone-like substances that control important physiological processes in the body, including blood pressure and the inflammatory response. Or they incorporate them into the lipid-rich membranes of every cell and every cell organelle in the body, where they add a much-needed degree of fluidity.
Polyunsaturated fatty acids are much more flexible than saturated fatty acids, making 180-degree, hairpin bends at each of their double bonds.They don’t pack as tightly as saturated fats, which is why they are liquids rather than solids at room temperature, giving membranes a much greater degree of fluidity. This fluidity is important to every cell in the body, since it allows enzymes and receptors embedded in those membranes to be much more responsive, but it’s especially important to nerve cells, which form thousands of high-speed connections.
However, there are tricks to these essential fatty acids that scientists have only been discovering in the last twenty years. Omega-3s and omega-6s cannot be substituted for each other in cell membranes without a significant change in function, a phenomenon that has been examined mostly in the brain, where the proportion of omega-3 fatty acids is the highest.10 Premature infants who are given formula that contains long-chain omega-6 fatty acids, but not omega-3s (the conventional formula until the fda approved omega-3 supplementation last year), experience a significant decrease in visual acuity and a loss of some eight iq points. Even full-term infants are significantly better at solving problems if given formula supplemented with omega-3 fatty acids for even the first four months of life.11
I could go on at length citing experiments that show the importance of omega-3s to normal brain function; however, the most important point is that these fatty acids have only one more double bond than their omega-6 counterparts. And what a difference, scientists are learning, a single double bond makes. Animals consistently select for long-chain omega-3 molecules for their most dynamic membranes—those involved in neurotransmission and light reception—just as plants select for the parent omega-3 molecule (ala) for their most dynamic, photosynthetic membranes. This biological parallel gives me goose bumps: it is as if animals have appropriated the membranes that plants use to convert light into chemical energy (or carbohydrates), enriched them, as befitting mobile creatures that require greater speed and responsiveness, and created membranes that can convert light into electrical signals and electrical signals into motion.
The hormone-like substances that are made from these two families of fatty acids do not act in similar ways either. In effect, they act in opposite and opposing ways. Eicosanoids (a group of twenty-carbon molecules that includes prostaglandins, leukotrienes, and thromboxanes) of the omega-6 family raise blood pressure, and eicosanoids of the omega-3 family lower it. Omega-6s induce the inflammatory and immune response, and omega-3s quell it.12 All of these reactions are necessary tools in the human body’s survival kit, but because omega-3s and omega-6s compete for the same enzymes that add double bonds and for the same ones that lengthen their carbon chains, they must be present in the diet in a somewhat balanced way. Modern technology has made it economical to produce oil from grains, and these oils have become the food staples of an increasing number of contemporary populations (and their domesticated animals); however, in many diets the omega-6s in these oils may be crowding out the omega-3s.13
This brings me back to the Israeli paradox, and the effects of a diet too high in omega-6s. It also brings me back to Taubes’s article, since omega-6 is a fat that does appear to make one fat. Israelis, as I have said, consume much less total fat than the American public (32.7 percent versus 43.9 percent of total calories) and fewer calories (mean food intake is 2999 kcal in Israel and 3455 kcal in the United States) and less animal fat. The Israelis have one of the highest polyunsaturated to saturated fat ratios in the world: 1.6 versus 0.63 in the United States. They also consume more carbohydrates than Americans (53.3 percent versus 44 percent of total calories) and plenty of fruits and vegetables, so their diet closely resembles the American food pyramid. Yet Israelis are more obese than Americans and have similarly high rates of diabetes, cardiovascular disease, and the cancers generally accepted to be related to fat consumption and obesity.
One might wonder if the difference is caused by the stress of living with the Arab-Israeli conflict; however, Arabs living in the same districts with Israelis have significantly reduced incidences of all those conditions. Genetics and cultural factors may play significant roles in the Israeli paradox, first alluded to in an article published in 1976, but even more important, some researchers believe, are the excessive amounts of omega-6 fatty acids in the Israeli diet. The Israelis rely heavily on soybean, cottonseed, corn, sunflower, and safflower oils for cooking, and all of these oils have extremely high ratios of omega-6s to omega-3s, 60:1 in the case of corn oil, 77:1 in the case of safflower oil. By contrast, the Arabs in Israel use olive oil as a cooking oil. Olive oil is not high in omega-3s, but neither is it high in omega-6s, and it is loaded with antioxidants (vitamin E) that prevent the double bonds in polyunsaturates from being oxidized. It also contains a substance called squalene that has been found to lower ldl, the so-called “bad” cholesterol.
“Israeli Jews may be regarded as a population-based dietary experiment on the effect of a high omega-6 pufa diet, a diet that until recently was widely recommended,” write the authors of a 1996 paper on the Israeli paradox. They point out that many of the diseases that are so prevalent in Israel—cardiovascular disease, hypertension, non-insulin-dependent diabetes mellitus, and obesity—are all diseases associated with insulin resistance and grouped together as the insulin resistance syndrome, or Syndrome X. In his article in the New York Times, Taubes links Syndrome X with the consumption of carbohydrates, especially refined carbohydrates, but we should also be aware of this association between omega-6s and Syndrome X.
Excessive omega-6 consumption is hypothesized to contribute to Syndrome X by increasing the secretion of insulin or by impairing insulin action, effects that are mediated via cell membranes through a reduction in the number and/or sensitivity of insulin receptors. It is hypothesized to contribute to coronary heart disease by reducing the levels of high-density lipoproteins (hdl); by producing eicosanoids that constrict the arteries, raise blood pressure, and cause platelets to clump or aggregate; and by interfering with the metabolism of omega-3s, fatty acids that have many of the opposite effects.
Israelis are not the only population experiencing the effects of a high omega-6 diet. There was a similar sharp increase in the prevalence of diabetes and heart disease in the upper socioeconomic classes in India after vegetable oils were substituted for the traditional cooking fat of ghee or clarified butter,14 and there is much concern among certain researchers that America may be going the same way as Israel, since omega-6 consumption in the United States is second only to Israel. In the past two decades, a growing body of research is linking a dietary excess of omega-6s (and/or deficiency of omega-3s) with most of our most common and intractable illnesses, not only heart disease and Syndrome X, but stroke, arthritis, allergies, many mental illnesses including depression and add, autoimmune disorders, and certain forms of cancer.15
Interestingly, the Finns have escaped any of the negative consequences of switching from saturated animal fats to unsaturated vegetable oils because the oil they switched to was rapeseed or canola oil,16 which has a more balanced ratio of omega-3s and omega-6s (as well as a high proportion of monounsaturated fats). The Finnish government had no idea that this was so when they promoted the use of rapeseed oil in order to reduce saturated fat intake; rape just happens to grow well in their northern latitudes. But rape, like other cold-adapted plants, has increased amounts of omega-3s in its leaves and seeds in order to germinate and photosynthesize at cold temperatures. So it is no accident that the Finns have had such success with rapeseed oil, and no accident that the Inuit were the first to teach us about the importance of omega-3s in the diet. The foods they eat—whales, seal, and fish—feed on other cold-adapted plants, the abundant algae and phytoplankton of the cold northern seas.
Some fats may make you fat, as the Israelis are finding out, and many fats—saturated, omega-6s, and trans-fats—are associated with heart problems and other diseases. But can fat actually help you to lose weight, as high-fat (low-carb) diets like the Atkins Diet claim? This is another aspect of Taubes’s article, which is, essentially, an apologia for the Atkins Diet and a throwback to the days when we knew very little about the differences between the different families of polyunsaturates.
Does the Atkins Diet work by magically suppressing hunger through the generation of ketone bodies and/or by eliminating the swings of blood sugar and insulin produced by carbohydrates in the diet? Or is it another low-calorie diet in disguise? By eliminating the option of eating (and overeating) bread, cakes, candies, French fries, ice cream, and a host of other high-carbohydrate foods, isn’t one likely to consume far fewer calories and, for that reason, to lose weight?
To put it another way, can you eat as much fat and protein as you like and still lose weight? Or do calories count in the Atkins Diet as in every other? I don’t have anything to add on the complex subjects of carbohydrate and fat metabolism and the insulin response produced by different foods (though critics of Taubes’s article have been quick to point out that insulin resistance in most people is the result of obesity, not its cause, and that some proteins produce an insulin response that is equal to some carbohydrates), but I do know of someone who can put to rest the debate over the way that the Atkins Diet works. He is Vilhjalmur Stefansson, the early twentieth-century Arctic explorer who spent much of his life promoting the health benefits of an all-meat diet, a man who was often described as “almost an Eskimo.”
When Stefansson first went to the Arctic in 1906, as a graduate student from Harvard, the accepted explanation for why the Eskimos (Inuits) were able to survive on the foods they ate was that they were fundamentally different from other people. It was thought that, over time, Eskimos had evolved special physiological mechanisms that reduced their need for carbohydrates and allowed them to live on a diet of mostly meat.
But Stefansson, as fate would have it, was separated almost immediately from his expedition party and taken in for a year by a group of Eskimos living on Herschel Island. Thus he came to learn from personal experience that Westerners could survive in the Arctic just as well as Eskimos— if only they dressed as the Eskimos dressed and ate what the Eskimos ate. Stefansson arrived in the Arctic with a childhood aversion to fish (he was a farm boy from North Dakota, after all), but he soon became “as fond of raw fish as though I were a Japanese.” He came to enjoy fermented whale oil with his fish “as well as ever I liked mixed vinegar and olive oil with a salad.”17
Stefansson was the first Westerner to recognize that fresh meat has enough vitamin C in it to prevent scurvy, and his controversial ideas about what it takes to prevent this devastating disease, the undoing of many sea voyages as well as Arctic expeditions, have stood the test of time. He also understood the role of large amounts of fat in the Inuit diet and the part that fats play in preventing protein starvation, or “rabbit starvation,” a wasting, often fatal condition caused by a diet that is too high in protein. Protein, as physiologists now know, causes a rise in the body’s heat or metabolism
as it is broken down, and this rise can be as high as thirty percent, versus six percent for fat or carbohydrates. Which means that for every hundred calories of protein eaten, thirty more are needed just to compensate for that metabolic increase, a vicious dietary circle that Stefansson describes
in his Arctic Manual.
“If you are transferred suddenly from a diet normal in fat to one consisting wholly of rabbit, you eat bigger and bigger meals for the first few days until at the end of about a week you are eating in pounds three or four times as much as you were at the beginning of the week,” Stefansson wrote, and I include his full description here because it shows the kinds of absolute dietary constraints that humans live with—that we cannot survive on just any diet that we dream up.
By then you are showing both signs of starvation and protein poisoning. You eat numerous meals; you feel hungry at the end of each; you are in discomfort through distention of the stomach with much food and you begin to feel a vague restlessness. Diarrhea will start in from a week to 10 days and will not be relieved unless you secure fat. Death will result after several weeks.18
Fat and fresh meat are the keys to the Inuit diet, Stefansson correctly surmised. What has not fared so well is his notion that all-meat diets are the healthiest diets and should be widely adopted, a notion that survives today in the Atkins Diet.
Stefansson began to challenge conventional wisdom linking heart disease to a diet rich in meat. Like other Arctic explorers, he had observed that the Inuit seemed to be immune to heart and artery disease. When he returned to the United States at the end of his three expeditions, he even offered himself up as a guinea pig, proposing that he live for an entire year on nothing but meat.
Few physicians thought this regimen was even possible, but in the winter of 1928, Stefansson and Karsten Anderson, a member of his third expedition, began a highly publicized and carefully supervised experiment at New York’s Bellevue Hospital. They would eat according to their individual tastes, but only steaks, chops, brains fried with bacon, boiled short ribs, chicken, fish, and liver, and they would be monitored by a panel of physicians who would record their vital functions and cut each portion of their food in half so that the macronutrient content of their diet—the protein, fat, and carbohydrates—could be accurately determined.19
To the doctors’ astonishment, both Stefansson and Anderson finished the year in good health with none of the deficiencies or problems, including kidney problems, that the doctors anticipated (except for a theoretical deficiency in calcium, the only mineral necessary to human survival that is lacking in meat).20 This is significant in itself, a proviso to those who would argue that the Atkins Diet is irresponsibly and universally dangerous. But what’s really significant about this experiment comes from the detailed records that were kept.
These records show, first of all, that neither Stefansson nor Anderson lost very much weight on this regimen. Stefansson lost five and a half pounds and Anderson lost six pounds—the amount of weight that a nutritionist today would predict that an Atkins dieter would lose during the first week or so, due to an immediate depletion of that person’s glycogen reserves and their associated water. Neither wanted to lose weight, of course, but the important point is that there is nothing magical about a diet of fat and protein. By eating as much meat as they liked, Stefansson and Anderson maintained their body weight, which supports the idea that in order to lose significant amounts of weight on this diet, as on any diet, one must eat a little less than one likes.
The second salient point to be garnered from the records of this experiment concerns the composition of the diet selected by Stefansson and Anderson. The Atkins Diet is usually described as a low-carb diet or a high-protein diet, but it is first and foremost a high-fat diet, as these records show. Both men consumed about 2600 calories a day, and both took a whopping three quarters of those calories from fat. The remaining quarter of their intake was from protein, with carbohydrate, in the form of glycogen in the meat, ranging from 20 to 50 calories per day. This ratio of fat they kept to naturally, they said, since a higher proportion of fat produced nausea and a higher proportion of protein, the beginning symptoms of rabbit starvation, “a feeling,” as Stefansson put it, “of general baffling discomfort.”21
Three quarters of their calories from fat: here is a figure that makes it obvious why this diet is both healthy—and possible—in the Arctic but not in other parts of the world. Northern sea mammals and fish require thick layers of blubber to insulate them from the cold of the Arctic waters and, because those animals feed on cold-adapted plankton and algae, those thick layers of blubber are rich in omega-3 fatty acids. In more temperate parts of the world, animals, especially wild animals, are not nearly so fat—and their fats are more saturated.
In most parts of the world, humans cannot rely on fats to meet their energy needs. They must use a combination of carbohydrates and fats. In most parts of the world, this is the healthiest diet: the one that spares proteins for the jobs that proteins do best, the one that best fuels all the organs of the body, including the brain—which prefers glucose (over ketones) as its energy source. Grain products may have been absent from the human diet until the invention of agriculture ten thousand years ago, as Taubes points out, but before humans ate grains, they ate carbohydrates and sugars in the form of tubers, roots, shoots, nuts, fruits, berries, leafy and starchy vegetables, and that most concentrated form of sugar—honey. It’s understandable that Stefansson failed to appreciate the role that carbohydrates play in most human diets and the special role that fats play in the Inuit diet—he lived before scientists understood the many differences in fats. However, people today have no such excuse.
Fats are a lot more interesting than Stefansson knew and a lot more complicated than Taubes has led us to believe. A decade ago, we thought that polyunsaturates were the key to health. Today, we are beginning to learn the difference between a diet that is rich in the fats of leaves and one that is rich in the fats of seeds and nuts, the difference of a single double bond. Does this mean that eating has become hopelessly complex? Or that we need to move to the Arctic to live longer, healthier lives? Nonsense, say the Greeks, who hold the secret to well-being in temperate parts of the world, a secret that includes (surprise, surprise) not only olive oil, but exercise, moderate amounts of meat, and plenty of fruit, fish, unrefined grains, and leafy green vegetables. If this sounds familiar, it is. It is the advice of many nutritionists and the voice of common sense. That voice is often drowned out by the latest scientific study, by wishful thinking, and by grocery store products that scream out their health benefits. But perhaps these stories from around the world will help keep it fresh in your mind as you ask yourself that all-important question: “What’s for dinner?”
1. Gary Taubes, “What if Fat Doesn’t Make You Fat?” New York Times Magazine, 7 July 2002.
2. National Health and Nutrition Examination Survey. Phase i, ii, and iii.
3. P. Pietinen, M. Lahti-Koski, E. Vartiainen, and P. Puska, “Nutrition and cardiovascular disease in Finland since the early 1970s: A success story,” The Journal of Nutrition, Health and Aging 5, no. 3 (2001): 150–154.
4. M.J. Karvonen, Maija Pekkarinen, and P. Metsala, “Diet and serum cholesterol of lumberjacks,” British Journal of Nutrition 15 (1961): 157–164.
5. Walter C. Willett, “Diet and Health: What should we eat?” Science 264
6. The agreement on trans-fatty acids is so widespread that even McDonald’s is changing its cooking oil to cut the trans-fatty acids in its food by half (New York Times, 4 September 2002).
7. Daniel Yam, Abraham Eliraz, and Elliot M. Berry, “Diet and Disease—The Israeli Paradox: Possible dangers of a high omega-6 polyunsaturated fatty acid diet,” Israel Journal of Medical Science 32, no. 11 (1996): 1134–1143.
8. J. Dyerberg, H.O. Bang, E. Stofferson, S. Moncada, and J.R. Vane, “Eicosapentaenoic acid and the prevention of thrombosis and atherosclerosis,” The Lancet 2 (1978): 117–119.
9. William E. Connor, “n-3 fatty acids from fish and fish oil: panacea or nostrum?” American Journal of Clinical Nutrition 74 (2001): 415–416.
10. Norman Salem, Jr., Burton Litman, Hee-Yong Kim, and Klaus Gawrisch, “Mechanisms of action of docosahexaenoic acid in the nervous system,” Lipids 36, no.9 (2001): 945–959; D.C. Mitchell, K. Gawrisch, B.J. Litman, and N. Salem, Jr., “Why is docosahexaenoic acid essential for nervous system function?” Biochemical Society Transactions 26 (1998): 365–370.
11. P. Willatts, J.S. Forsyth, M.K. DiModugno, S. Varma, and M. Colvin, “Effect of long-chain polyunsaturated fatty acids in infant formula on problem solving at 10 months of age,” The Lancet 352 (1998): 688–691; William E. Connor, “Importance of n-3 fatty acids in health and disease,” American Journal of Clinical Nutrition 71, Supplement (2000): 171s–175s.
12. Artemis P. Simopoulos, m.d., and Jo Robinson, The Omega Plan (New York: HarperCollins, 1998).
13. Researchers don’t know at this point if there’s an optimal ratio of omega-6s to omega-3s in the diet (or whether what is important is just that both be present in healthy amounts), but the World Health Organization has recommended a ratio of 5–10:1 and Japan has recently changed its recommendations from 4:1 to 2:1. Meanwhile, the u.s. does not even distinguish between omega-6s and omega-3s in its dietary recommendations, an omission, some say, that has to do with the power of the edible oils industry.
14. Yam et al, “Diet and Disease—The Israeli Paradox,” 1139.
15. Connor, “Importance of n-3 fatty acids in health and diseases,” 171s.
16. Personal communication with Leena Rasanen.
17. Vilhjalmur Stefansson, “Adventures in Diet,” Harper’s Magazine, November 1935, 671; Stefansson, My Life with the Eskimo (New York: Collier, 1913).
18. Vilhjalmur Stefansson, Arctic Manual (New York, 1944).
19. Clarence W. Lieb, m.d. “The effects on human beings of a twelve months exclusive meat diet,” Journal of the American Medical Association, 6 July 1929, 20–22.
20. Calcium is present in bones, of course, and the Inuit chew on bones as a regular part of their diet. But bones were not a part of Stefansson and Anderson’s experimental regimen.
21. Stefansson, “Adventures in Diet,” Harper’s Magazine, December 1935.
12/14/2004 6:28pm, #2
I think it must be mandatory for people that aren't in great shape to try and find obscure reasons to drink milk and eat doritos and then wonder why others are in better shape than they are."All warfare is based on deception." -Sun Tzu, ca. 400BC
Reverse punch Kiaii!!!
12/14/2004 6:33pm, #3
You're holding out on me. You actually read that...on the internet!
12/14/2004 6:34pm, #4
Seriously though...tell me more about Arnold's valve surgery.
12/14/2004 8:05pm, #5Originally Posted by PeedeeShaolin
Since everyone said that...
12/14/2004 9:07pm, #6
Was this a school essay or something?
12/15/2004 2:17am, #7
Can someone summarise it for me please?
Something about a lineage war or something...
12/15/2004 2:31am, #8
It's basically a detailed investigation into whether fats are good or bad for you, as with the other macronutrients.
The answer: Some are, some aren't. When Japanese people don't get enough fat, they die from stroke, but not cancer. When they get MORE fat from western-style diets, they have lower stroke fatalities, but higher cancer ones.
Finnish people stopped dying from coronary heart disease so frequently by government initiatives to switch from animal-based to veggie-based oils.
Oils and foods with extremely high Omega-6 to Omega-3 ratios are bad for you.
ANd so on.
12/15/2004 4:16am, #9
Fat doesn't make you fat. Carbs don't make you fat. Protein doesn't make you fat. Calories make you fat, short and simple. When weight gain is concerned, anything else is just meaningless chatter. Granted, different nutrients can contribute to health a lot more than others (for example, studies show that saturated fat intake, not cholesterol intake is the single largest factor determining one's blood cholesterol level).
And if you can't tell, no I didn't read more than the first paragraph of the article. Tl;drClick To Get My Free Training Newsletter... Do It NOW!
"You all just got fucking owned.";
"TaeBo_Master and GajusCaesar just scored 10,000,000 points on all you pawns."
- The Wastrel
12/15/2004 10:21pm, #10
I didn't even read it at all. :)