78 THE CHINA STUDY measure dietary cholesterol any more than he or she can measure how many hot dogs and chicken breasts you've been eating Instead, the doctor measures the amount of cholesterol present in your blood This second type of cholesterol, blood cholesterol, is made in the liver Blood cholesterol and dietary cholesterol, although chemically identical, not represent the same thing A similar situation occurs with fat Dietary fat is the stuff you eat: the grease on your French fries, for example Body fat, on the other hand, is the stuff made by your body and is very different from the fat that you spread on your toast in the morning (butter or margarine) Dietary fats and cholesterol don't necessarily turn into body fat and blood cholesterol The way the body makes body fat and blood cholesterol is extremely complex, involving hundreds of different chemical reactions and dozens of nutrients Because of this complexity, the health effects of eating dietary fat and dietary cholesterol may be very different from the health effects of having high blood cholesterol (what your doctor measures) or having too much body fat As blood cholesterol levels in rural China rose in certain counties, the incidence of "Western" diseases also increased What made this so surprising was that Chinese levels were far lower than we had expected The average level of blood cholesterol was only 127 mg/dL, which is almost 100 points less than the American average (215 mg/dL)! 12 Some counties had average levels as low as 94 mg/dL For two groups of about twenty-five women in the inner part of China, average blood cholesterol was at the amazingly low level of 80 mg/dL If you know your own cholesterol levels, you'll appreciate how low these values really are In the U.s., our range is around 170-290 mg/dL Our low values are near the high values for rural China Indeed, in the U.s., there was a myth that there might be health problems if cholesterol levels were below 150 mg/dL If we followed that line of thinking, about 85% of the rural Chinese would appear to be in trouble But the truth is quite different Lower blood cholesterol levels are linked to lower rates of heart disease, cancer and other Western diseases, even at levels far below those considered "safe" in the West At the outset of the China Study, no one could or would have predicted that there would be a relationship between cholesterol and any of the disease rates What a surprise we got! As blood cholesterol levels decreased from 170 mg/dL to 90 mg/dL, cancers of the liver,1I rectum/ colon, II male lung; female lung, breast, childhood leukemia, LESSONS FROM CHINA 79 adult leukemia,1 childhood brain, adult brain,1 stomach and esophagus (throat) decreased As you can see , this is a sizable list Most Americans know that if you have high cholesterol, you should worry about your heart, but they don't know that you might want to worry about cancer as well There are several types of blood cholesterol, including LDL and HDL cholesterol LDL is the "bad" kind and HDL is the "good" kind In the China Study higher levels of the bad LDL cholesterol also were associated with Western diseases Keep in mind that these diseases, by Western standards, were relatively rare in China and that blood cholesterol levels were quite low by Western standards Our findings made a convincing case that many Chinese had an advantage at the lower cholesterol levels, even below 170 mgldL Now imagine a country where the inhabitants had blood cholesterol levels far higher than the Chinese average You might expect that these relatively rare diseases, such as heart disease and some cancers, would be prevelant, perhaps even the leading killers! Of course, this is exactly the case in the West To give a couple of examples at the time of our study, the death rate from coronary heart disease was seventeen times higher among American men than rural Chinese men 13 The American death rate from breast cancer was five times higher than the rural Chinese rate Even more remarkable were the extraordinarily low rates of coronary heart disease (CHD) in the southwestern Chinese provinces of Sichuan and Guizhou During a three-year observation period (1973-1975), there was not one single person who died of CHD before the age of sixty-four, among 246,000 men in a Guizhou county and 181 ,000 women in a Sichuan county! 14 After these low cholesterol data were made public, I learned from three very prominent heart disease researchers and physicians, Drs Bill Castelli, Bill Roberts and Caldwell Esselstyn, Jr., that in their long careers they had never seen a heart disease fatality among their patients who had blood cholesterol levels below 150 mgldL Dr Castelli was the long-time director of the famous Framingham Heart Study of NIH; Dr Esselstyn was a renowned surgeon at the Cleveland Clinic who did a remarkable study reversing heart disease (chapter five); Dr Roberts has long been editor of the prestigious medical journal Cardiology 80 THE CHINA STUDY BLOOD CHOLESTEROL AND DIET Blood cholesterol is clearly an important indicator of disease risk The big question is: how will food affect blood cholesterol? In brief, animalbased foods were correlated with increasing blood cholesterol (Chart 4.5) With almost no exceptions, nutrients from plant-based foods were associated with decreasing levels of blood cholesterol Several studies have now shown, in both experimental animals and in humans, that consuming animal-based protein increases blood cholesterollevels 1s- 18 Saturated fat and dietary cholesterol also raise blood cholesterol, although these nutrients are not as effective at doing this as is animal protein In contrast, plant-based foods contain no cholesterol and, in various other ways, help to decrease the amount of cholesterol made by the body All of this was consistent with the findings from the China Study CHART 4.5 FOODS ASSOCIATED WITH BLOOD CHOLESTEROL As intakes of meat,' milk, eggs, fish,'-" far and animal protein go up Blood Cholesterol goes up As intakes of plant-based foods and nutrients (ineluding plant protein,' dietary fiber," cellulose," hemicellulose,' soluble carbohydrate," B-vitamins of plants (carotenes, B2 , B3 ),' legumes, light colored vegetables, fruit, carrots, potatoes and several cereal grains) go up Blood Cholesterol goes down These disease associations with blood cholesterol were remarkable, because blood cholesterol and animal-based food consumption both were so low by American standards In rural China, animal protein intake (for the same individual) averages only 7.1 glday whereas Americans average a whopping 70 glday To put this into perspective, seven grams of animal protein is found in about three chicken nuggets from McDonald's We expected that when animal protein consumption and blood cholesterol levels were as low as they are in rural China, there would be no further association with the Western diseases But we were wrong Even these small amounts of animal-based food in rural China raised the risk for Western diseases We studied dietary effects on the different types of blood cholesterol The same dramatic effects were seen Animal protein consumption by LESSONS FROM CHINA 81 men was associated with increasing levels of "bad" blood cholesterolIIl whereas plant protein consumption was associated with decreasing levels of this same cholesterol II Walk into almost any doctor's office and ask which dietary factors affect blood cholesterol levels and he or she will likely mention saturated fat and dietary cholesterol In more recent decades, some might also mention the cholesterol-lowering effect of soy or high-fiber bran products, but few will say that animal protein has anything to with blood cholesterol levels It has always been this way While on sabbatical at the University of Oxford, I attended lectures given to medical students on the dietary causes of heart disease by one of their prominent professors of medicine He went on and on about the adverse effects of saturated fat and cholesterol intakes on coronary heart disease as if these were the only dietary factors that were important He was unwilling to concede that animal protein consumption had anything to with blood cholesterol levels, even though the evidence at that time made it abundantly clear that animal protein was more strongly correlated with blood cholesterol levels than saturated fat and dietary cholesterol 15 Like too many others, his blind faith in the status quo left him unwilling to be open-minded As these findings poured in, was beginning to discover that being open-minded was not a luxury, but a necessity FAT AND BREAST CANCER If there were some sort of nutrition parade, and each nutrient had a float, by far the biggest would belong to fat So many people, from researchers to educators, from government policy makers to industry representatives, have investigated or made pronouncements on fat for so long People from a huge number of different communities have been constructing this behemoth for over half a century As this strange parade got started on Main Street, USA, the attention of everyone sitting on the sidewalks would ineVitably be drawn to the fat float Most people might see the fat float and say, "I should stay away from that," and then eat a hefty piece of it Others would climb on the unsaturated half of the float and say that these fats are healthy and only saturated fats are bad Many scientists would point fingers at the fat float and claim that the heart disease and cancer clowns are hiding inside Meanwhile, some self-proclaimed diet gurus, like the late Dr Robert Atkins, might set up shop on the float and start selling books At the 82 THE CHINA STUDY end of the day the average person who gorged on the float would be left scratching his head and feeling queasy, wondering what he should have done and why There's good reason for the average consumer to be confused The unanswered questions on fat remain unanswered, as they have for the past forty years How much fat can we have in our diets? What kind of fat? Is polyunsaturated fat better than saturated fat? Is monounsaturated fat better than either? What about those special fats like omega3, omega-6, trans fats and DHA? Should we avoid coconut fat? What about fish oil? Is there something special about flaxseed oil? What's a high-fat diet anyway? A low-fat diet? This can be confusing, even for trained scientists The details that underlie these questions, when considered in isolation, are very misleading As you shall see, considering how networks of chemicals behave instead of isolated single chemicals is far more meaningful In some ways, however, it is this foolish mania regarding isolated aspects of fat consumption that teaches us the best lessons Therefore, let's look a little more closely at this story of fat as it has emerged during the past forty years It illustrates why the public is so confused both about fat and about diet in general On average, we consume 35-40% of our total calories as fat 19 We have been consuming high-fat diets like this since the late nineteenth century, at the onset of our industrial revolution Because we had more money, we began consuming more meat and dairy, which are relatively high in fat We were demonstrating our affluence by consuming such foods Then came the mid to late twentieth century when scientists began to question the advisability of consuming diets so high in fat National and international dietary recommendations 2°-B emerged to suggest that we should decrease our fat intake below 30% of calories That lasted for a couple decades, but now, the fears surrounding high-fat diets are abating Some authors of popular books even advocate increased fat intake! Some experienced researchers have suggested that it is not necessary to go below 30% fat, as long as we consume the right kind of fat The level of 30% fat has become a benchmark, even though there is no evidence to suggest that this is a vital threshold Let's get some perspective on this figure by considering the fat contents of a few foods, as seen in Chart 4.6 ... as low as they are in rural China, there would be no further association with the Western diseases But we were wrong Even these small amounts of animal-based food in rural China raised the risk... At the 82 THE CHINA STUDY end of the day the average person who gorged on the float would be left scratching his head and feeling queasy, wondering what he should have done and why There's good... kind In the China Study higher levels of the bad LDL cholesterol also were associated with Western diseases Keep in mind that these diseases, by Western standards, were relatively rare in China