Mental biases; health by subtraction
People love to hear good news about their bad habits.
—John McDougall, M.D.
Vegetarians have the best diet [and] the lowest rates of coronary
heart disease of any group in the country. —William Castelli, M.D.
In the late 1800s, a young Scottish physician was experiencing difficulty in establishing his medical practice. With time on his hands, the young man turned his remarkable mind to the telling of mysteries and their solutions. In contrast to his struggling practice, his writing was an immediate and astounding success. The young doctor's name was Doyle, and his literary creation, Sherlock Holmes, would become synonymous with deductive genius for generations to come.
Though a fine storyteller with a flair for both humor and drama, perhaps Sir Arthur Conan Doyle's greatest talent was his penetrating vision into the nature of human problem-solving. In particular, Doyle had an uncanny sense for spotting problem-solving blind-spots, mental biases to which he made sure that the great Holmes was immune. Indeed, a crucial component of Holmes's timeless appeal is his ability to make sense out of what less gifted observers might view as insufficient or contradictory evidence.
Holmes's special talent is his ability to appreciate the importance of clues that others fail to notice, though their importance is obvious once seen from the proper perspective. Often this requires the great detective to look at the evidence from a viewpoint that is precisely opposite from the one that seems naturally right. One classic Holmes mystery, Silver Blaze, beautifully illustrates this point.
In the story, the victim, a resident of the estate, is found one morning on the grounds, having been felled by a blow to the head the previous evening. The evidence strongly suggests that the culprit is a stranger who had been observed on the estate's grounds earlier that same day. The police apprehend the suspect and are intending to charge him with the crime when Holmes intervenes, insisting to the police that they have made a mistake.
The case turns on an obscure but key point, when, after questioning witnesses, Holmes recognizes a critical fact that others had missed. The estate housed many people, horses, and an alert stable dog. The great Holmes explains to his astounded listeners that the key to the case is the "curious incident of the dog in the night-time." Before he can continue, a listener objects, insisting that "the dog did nothing in the night-time."
"That was the curious incident," replies Holmes.
Holmes explains that the absence of the dog's barking suggested to him that the culprit was known to the manor's hound and could therefore not have been the stranger. This indicated a need to re-examine the evidence from a fresh perspective. Holmes solves the mystery because of his brilliant awareness that the absence of something can be more important than its presence.
This truth is often difficult to grasp. The difficulty is the result of a natural human problem-solving blind spot, an innate limitation of our psychology. It is precisely this type of human limitation that Arthur Doyle was so adept at noticing. And it is this type of limitation that results in the majority of our society remaining blind to the key facts regarding their health, though the facts are crystal clear once seen from the proper perspective.
Millions of people in our country are suffering and dying from a handful of devastating conditions, including heart attack, stroke, congestive heart failure, diabetes, and cancer. These conditions account for three-fourths of our nation's premature deaths and the majority of our collective chronic disability.1 Yet the culprits in these tragedies have been hard for most people to accurately identify. The evidence, for many, appears to be contradictory and confusing. Like a Sherlock Holmes mystery, people are puzzled about the causes of their health problems, as well as what to do about them. They look to experts in books, television, the Internet, and to their doctor. More than 10 million people search the Internet each week seeking health-related information, making health information-seeking one of our population's primary intellectual pursuits. This is appropriate, as our health problems are of epidemic proportions.
Unfortunately, most of the "expert" information dispensed is erroneous and misleading. For example, people are often told that the real culprits causing their health problems are their genes. This suggests that any solution to their problems will require medical intervention because their body simply doesn't work properly. If they have high cholesterol, they are told to ingest cholesterol-lowering drugs. If they have high blood pressure, they are encouraged to ingest medications that will lower it. And if they have type 2 diabetes (about 95 percent of all diabetes cases), they are told that their health requires that they utilize medication.
In the alternative health arena, the "expert" suggestions are somewhat different. Herbal remedies, concentrated foodstuffs in the form of pills, vitamin supplements, and other treatments are the standard fare. Similar to conventional thought, such alternative approaches seem to confirm the same unspoken conclusion: The body of a person with a health problem cannot be expected to achieve and sustain a healthy state without adding something. Either by virtue of genetic flaw or because of dietary deficiency, the notion once again is that something is missing. The response to "take something for it" makes intuitive sense to most people, often encouraging them to continue down a path of self-destruction. Meanwhile, the real culprits are ignored and continue to do their damage unchecked.
The Real Culprits The real culprits in most modern-day health problems are excesses, not deficiencies. It is the subtraction of these excesses that will solve most of the problems, not the addition of medications or supplements. Not surprisingly, the subtraction of excess is nearly always more effective at restoring health than is the addition of anything, be it dietary supplements or medications.
In atherosclerosis, for example, excess cholesterol, fat, and protein (mostly in the form of animal products) result in deposits of fatty substances within the cardiovascular system. These deposits clog up the system and contribute to heart attack, stroke, and congestive heart failure. The risk of such vascular diseases is associated with cholesterol levels, which are heavily influenced by our dietary cholesterol intake. Cholesterol is found in all foods of animal origin, including meat, fish, fowl, eggs, and dairy products. Plant-based foods contain zero cholesterol.
The dangers of a high-fat, high-animal product diet with respect to cardiovascular disease has been made apparent by epidemiological studies such as the Framingham Heart Study, directed for more than twenty years by William Castelli, M.D. Castelli and his colleagues have documented the critical importance of dietary choices in disease prevention. While more than one in four men in the study who consumed a conventional diet succumbed to a heart attack, those who consumed a plant-based diet were extremely well protected. This is not surprising, as vegan-vegetarians (those who eat no animal foods) have cholesterol levels that are 35 percent lower than nonvegetarians.2 Dr. Castelli has reported that in 35 years of the Framingham Study, no subject with a cholesterol level under 150 ever suffered a heart attack.3 Controlling dietary excesses is clearly the key to preventing cardiovascular disease.
Research has shown that the subtraction of these dietary excesses is the most effective way to manage the problem. In the Lifestyle Heart Trial, Dr. Dean Ornish and his colleagues conclusively demonstrated that by dramatically reducing the amount of animal product in the diet, and by reducing fat intake from about 40 percent to about 10 percent of calories consumed, the body will soon begin to reverse the atherosclerosis. No medication or nutritional supplement additive has shown even remotely equivalent success.4
Not Elementary Sherlock Holmes was fond of explaining to his sidekick, Dr. Watson, that the connections he made were "elementary." Of course, nothing could have been further from the truth. Although obvious once viewed from the proper perspective, the solution to a Sherlock Holmes mystery is an exciting moment for the reader, as Holmes brilliantly maneuvers those present into seeing the facts in an accurate new light. This solution usually begins with a startling conceptual leap.
Grasping that the major key to health is mostly about subtraction and not addition is a major conceptual leap. Although seemingly simple, this connection is perhaps the most difficult principle in modern health science to understand. Once seen from the proper perspective, it is simple. But achieving this understanding can be a challenging task.
After many years of experience with patient education, we have come to believe that there is a mechanism that is responsible for this misunderstanding.
DEAN'S DISCOVERY
In the 1970s, animal studies suggested that a deadly disease, atherosclerosis, could be reversed with dietary intervention. Specifically, a low-fat, vegetarian diet was found to successfully reverse heart disease in several omnivorous species. A young physician, Dr. Dean Ornish, decided to test whether the same results could be obtainable in human subjects. In the 1980s, he and his team set forth to investigate this possibility.
The results of his landmark study, published in the prestigious journal Lancet, astonished a medical profession unfamiliar with the potential of honest-to-goodness health-promoting behavior changes. While the average patient consuming the recommended American Heart Association diet (30 percent calories from fat, including "lean" animal portions) increased his or her arterial blockages by 28 percent, the average patient in Dr. Ornish's study (consuming a near-vegetarian diet of about 10 percent fat) decreased his or her arterial blockages by 8 percent. Invasive drugs and surgical techniques, in the vast majority of cases, were found to be unnecessary.
There must be a powerful reason that humans continue to believe that adding vitamin pills, medication, wine, and aspirin is useful for the pursuit of cardiovascular health. There must be a powerful reason that such errant solutions seem more plausible than the truth—the fact that what we need to do is to subtract meat, fish, fowl, eggs, dairy products, alcohol, and tobacco from our diet. And although the human pleasure-seeking drive might motivate patient resistance to the truth, we don't think that this is the core of the problem. And although massive misinformation campaigns by
THE MCDOUGALL WAY
For three decades, Dr. John McDougall has sought to educate his colleagues and the public about the health-promoting benefits of subtracting dietary excesses. As a young physician in Hawaii in the 1970s, Dr. McDougall made the observation that while his younger patients experienced a great deal of illness, his older patients were comparatively healthy. Working with the native Hawaiian population as a rural doctor, he became aware of significant dietary differences between the older and younger generations. Specifically, younger generations were enamored with modern American high-fat, high-sugar, processed fare.
Dr. McDougall began an exhaustive review of the scientific evidence linking dietary patterns to disease. The results left him convinced that excesses of fat and protein, particularly of animal origin, together with excesses of refined carbohydrates and recreational drugs, were at the root of emerging health crises. After observing his patients recover their health when converted to healthful living, McDougall then sought to demonstrate the importance of these practices to his colleagues.
McDougall and his associates have shown that in just 12 days the average patient in his program reduced their serum cholesterol by 28 mg/dl. For patients with high cholesterol levels (>300 mg/dl) the reduction was a spectacular 62 mg/dl!
Most cardiologists are fond of telling their patients with high cholesterol levels that they shall "need to take medication for the rest of your life." The superb work of Drs. McDougall and Ornish conclusively contradicts this notion. Quite to the contrary, the most potent solution is not to add medication, but rather to subtract the cause.5
commercial interests lead the unwary down a false trail, our experience suggests that a more fundamental factor is at the root of this misunderstanding.
We suspect that the human brain is biased against accepting that dietary excesses are the root of most health problems, and thus the difficulty grasping this truth despite the scientific evidence. Conversely, the idea that some sort of deficiency is responsible continues to be popular. This is probably because such a concept has intuitive appeal.
Sir Arthur Conan Doyle unwittingly anticipated one of the most important discoveries of modern psychology. As he suspected, human brains are not impartial judges of the facts. Brains come into being with hard-wired biases, that is, tendencies to see some connections much more readily than others. The brains of humans (and other animals) are much more likely to see connections that they expect to see, and the connections that they expect to see are often those that were important to notice throughout the natural history of the species.6
In the ancient world, people never faced problems resulting from dietary excesses. This is because the natural landscape is not replete with excessive animal proteins and fats in the form of things like cheese, ice cream, and butter. The natural world contains no processed oils, refined sugar and flours, or excessive sodium. And since dietary excesses were not a factor in our evolutionary history, we are not well equipped to discern that health problems might be the result of these excesses.
Dietary deficiencies, on the other hand, were often a serious problem for our ancestors. Getting enough to eat has always been one of the major problems of human life. People who walk the earth today are all descendants of those who faced the problem of getting enough, as opposed to worrying about getting too much. As such, the neurological circuits that make up the human mind are naturally concerned with deficiency. This bias makes it difficult for us to grasp that dietary excesses are at the root of our modern health problems.* (See endnote, p. 212.)
Pecking the Right Key Neurological biases are now being discovered throughout the animal kingdom, but until the concept of biased brains was itself recognized, many important facts were ignored. For example, psychologists such as B.F. Skinner, who were attempting to understand the laws of learning, performed a great many experiments with pigeons. In attempting to teach pigeons new behavior, these psychologists would light a key which would result in a food reward when pecked. This method was used for decades without question. Then one day a psychologist wondered if the pigeon could be trained equally effectively by having a continuously lighted key go dark in order to signal the pigeons to peck. He decided to put this question to the test.
To the surprise of animal psychologists, his results showed that pigeons cannot be trained to seek a reward by pecking a key that has suddenly gone from light to dark! While in principle such an event is precisely as informative as having a darkened key suddenly becoming lighted, it is a connection that a pigeon cannot make. And while we might think that the pigeon is just "stupid," such a judgment would miss the key point, which is that similarly, people will not normally grasp the importance of a dog not barking in the night.
The Case of the Missing Zero While the study of animal mental biases can be fascinating, the vital question is whether these ideas can teach us anything useful about ourselves. Is it true that the human mind is also born with biases? Over the last two decades, research has shown that the answer to this question is a resounding yes. Professors Daniel Kahneman and the late Amos Tversky jointly won the American Psychological Association's highest honor in 1982 for their investigations into these phenomena. Their many demonstrations of our natural limitations have become classics in modern psychological science.
But it is not just psychological science that gives us evidence of our natural limitations. Throughout human history there are many examples where human intuition has shown its limits. It was very difficult, for example, for people to grasp the concept that the earth is round and that it moves around the sun, despite adequate evidence. Similarly, it was exceedingly difficult for people to grasp the concept of the number zero, a problem that limited early mathematics.
Today, these concepts are obvious. The number "307" means "3 × 100, plus 0 × 10, plus 7 × 1." But for ancient peoples, such an accounting was not possible. The Babylonians, despite their many mathematical feats, did not grasp the significance of the number zero for centuries, until about 350 B.C. Throughout history, computations and records were exceedingly poor until these concepts were firmly understood. It was not until 1200 A.D. that the Hindus began using zero in their computations after eons of making countless unnecessary errors. The notion that "nothing" needs to be denoted as "something" (zero) was lost to the vast majority of the world's intellectual elite until quite recently.7 Yet the counting of "something" comes as naturally as "one, two, three" and goes back as far as we have records with numbers.
One can imagine the consternation of early mathematicians and accountants struggling to understand why their numbers often didn't add up. But if we slightly alter our perspective and use our imagination, we can also see why this was so difficult. Starting without the proper framework, it isn't at all obvious that the earth is a sphere and that it moves around the sun. And it is not at all clear that the absence of a number is as important as its presence. Though obvious to us, these concepts are not elementary challenges for the natural human mind.
We now know that people have many biases, or problem-solving blind spots. But although people appear to have a natural bias against the concept of dietary excess, once seen from the proper perspective, the problem becomes obvious. Once we grasp what the scientific evidence is telling us—no matter how counterintuitive the findings appear—we can see the evidence everywhere. Wherever we look, people are struggling with obesity, the ultimate evidence of dietary excess. Once we observe what people in our society actually eat, the connection between dietary excess and health compromise is clear.
If we then follow the evidence and the logic, we can assume that the solution is to subtract foods of excess from our daily fare. And, as we subtract meat, fish, fowl, eggs, dairy products, oil, salt, sugar, and refined carbohydrates from our diet, what remains are foods that promote health. Fresh fruits and vegetables, tubers, whole grains, legumes, and nuts and seeds fill the void after the subtraction has taken place. In response, the previously overburdened body begins to regain its health.
Dr. Doyle Would Approve If most health problems are caused by dietary excesses (and they are), then it makes sense that the subtraction of such excesses is likely to be an effective treatment strategy. Landmark investigations by Drs. Dean Ornish, John McDougall, Caldwell Esselstyn, Jr., and others have confirmed that this is true.
The results achieved by our patients through dietary modification are often spectacular by conventional standards. The power of the body's ability to recover its health is remarkable. And, although most modern "experts" of both conventional and alternative persuasions resist these facts, we are confident that the evidence will eventually make the truth obvious. We are also confident that at least one nineteenth-century Scottish physician would have had no trouble grasping this counterintuitive principle of health. In fact, he probably would have begun his explanation with his favorite prelude. After all, once seen from the proper perspective, the importance of eliminating dietary excesses is "Elementary, my dear Watson…"
DR. CALDWELL ESSELSTYN, JR.
Most physicians reassure their patients that "everything in moderation" is acceptable. Not so, says Caldwell Esselstyn, Jr., M.D., a nationally acclaimed surgeon at the Cleveland Clinic in Ohio. As the former president of the American Association of Endocrine Surgeons, Dr. Esselstyn is well aware of the current state of conventional medical thought and advice. "Oil, dairy, and meat are atherosclerotic linchpins," says Dr. Esselstyn. "We must eliminate the lethal phrase, 'this little bit won't hurt.'"
His own research paralleling that of Dr. Dean Ornish, Esselstyn has documented the most successful cardiovascular reversal program on record. In his study, patients who complied with the program and who had collectively experienced 48 cardiac events prior to the program experienced zero cardiac events during the subsequent twelve-year program.8 His success lies in his relentless, but caring, insistence on a health-promoting, plant-based diet. One woman, after her second heart attack, was told by her cardiologist to go home and prepare to die. Fortunately, she was introduced to Dr. Esselstyn and was persuaded to become a research subject in his program. Her outcome thus far is somewhat better than would have been expected from standard medical care. At her fifteen-year checkup, she was still going strong.
Throughout our history, dietary deficiencies were common, while dietary excesses were rare. It is no surprise, then, that our psychology is designed to be concerned about deficiencies, and not excesses. This natural characteristic makes it difficult for modern people to grasp the real causes of most contemporary health problems. Instead, both health professional and patient search for something to add to the patient's body—some vitamin pill, potion, "medicine," or food supplement that might help to restore health.
Unfortunately, in the great majority of cases, both physician and patient are looking for health in the wrong place. It is rarely the case that something needs to be added to the patient's body. Instead, dietary excesses need to be subtracted. The most potent health-promoting move is usually the subtraction of meat, fish, fowl, eggs, dairy products, processed oils, salt, refined carbohydrates, and recreational drugs. The scientific evidence provided in landmark investigations by Drs. Ornish, McDougall, Esselstyn, Castelli, and others overwhelmingly supports this position.
1. Health is best supported by the removal of all meat, fish, fowl, eggs, dairy products, and added oil, salt, sugar, and refined carbohydrates. Also to be avoided are recreational drugs such as alcohol, caffeine, and tobacco.
2. Health is most effectively promoted by healthful living—consuming a diet of whole natural foods, exercising, getting appropriate rest, and avoiding toxic substances. Such a lifestyle not only prevents disease, but in many cases, is able to reverse disease and help restore health and well-being.