*** The China Study by Colin Campbell

This was one of the hardest books to read, not because of the language or complexity of the topic, but because I love eating meat and animal products. That’s right I enjoy steak, lamp chops, hamburgers, thanksgiving turkey, fish, omelets, ice cream, cheese – you name it. I try to eat low fat version of these foods and augment it with whole grains and vegetables. But now, to my horror and dismay, animal protein is a major culprit for cancer, diabetes, autoimmune disease, heart disease. I’d like to find some holes in this theory so I can keep on eating the things I like. Perhaps I’ll learn to love tofu, beans, and cruciferous vegetables. What’s my takeaway from all of this relative to what I know so far?

1. Vitamin D from sunlight is critical. Even if you live in the SF Bay Area (Latitude of 43 degrees), the sun’s rays will not be strong enough to activate vitamin D between Nov-Mar. Places like San Diego, Tucson and further south are OK in the winter. Supplementation may help, especially during that time of the year.

2. Consuming dairy products is not good for you. If you can give up dairy, you’re probably going to be better off. The risks for consuming far outweigh any potential benefits (there don’t seem to be any scientifically published benefits that I’m aware of). This is very hard considering that it means butter, milk, ice cream, yogurt, cheese are forbidden! I just started diluting my regular milk w/soy milk. And I’ll try to cutback even more, but pizza w/o cheese? That’s going too far!

3. Supplements don’t work. That means taking vitamins, eating extra fiber supplements (or processed food with added fiber) won’t help you. You’ve got to eat the whole food to get the benefit. Why? Because we don’t know what in the food actually helps us (or perhaps what in the food hurts us the least if you consider all food as a potential poison which may be why caloric restriction is the only proven way to live longer). So you’ll have to eat the whole damn tomato, squash, wheat grain – not just pop a pill at the end of your meal.

4. Humans are not carnivores, we’re omnivores. The mainstay of our diet was probably vegetables and fruits with some grains and nuts. Meat was occasionally, and probably not eaten daily, let alone at every meal. But it was eaten. So if you can’t give up meat (like me!), just eat it less often and in smaller portions. It shouldn’t be the focus of the meal on your plate. Also, fish and shellfish are probably safer bets than other animal foods.

5. Eat as many vegetables and fruits as you want with impunity. No harm can come from overeating these foods. Go nuts! Sorry, nuts need to be eaten in moderation because they are so calorie dense. Go bananas instead.

6. Stop eating processed food. The best of it is really garbage disguised with vitamin and fiber supplements, but it is of no use to your body. Whole grains and whole fruits/vegetables are sadly the only choice. So when the cereal or granola bar box says enriched grain, 10 grams of fiber, 100% USRDA of your daily vitamins, but the label on the side written in microscopic print says the ingredients contain enriched flour with 47 different chemicals listed after that, you’re basically eating a doughnut with a vitamin pill.

7. Stop eating like a pig. My suggestion – the Ben Sharma diet to be exact – is to eat 3 fruits or vegetables before every meal. After that, eat the rest of your regular meal until you’re full. If you did this, you’d get 9 servings of fruits & veggies per day, and hopefully the extra bulk will take the wind out your appetite’s sails.

8. Exercise to make up for all of the mistakes that go into your mouth. Eating is a very pleasurable thing, so don’t give it up. Once in a while, you’ll want to indulge. So don’t hold back on those rare occasions. Why? Because exercising will help you get over that like a little speedbump. But if you don’t exercise, eating just 50 calories per day (1 bite of a candy bar) will pile on about 10lbs of fat per year. Exercise will also boost your immune system, strengthen your muscles and bones, improve your cardio-vascular system, keep mental deterioration at bay, improve your sex drive, and on and on.

9. Take a baby aspirin and chill out. Inflammation can kill you, and aspirin helps keep inflammation down and reduces clotting (the real killer for heart attack and stroke). Drinking in moderation may also help you relax and reduce inflammation.

10. “Do all things in moderation, including moderation.” – Oscar Wilde. Hey, you only live once, and we all know how the story will end. So have some fun. Eat drink and be merry.

[Philippine] children who ate the highest protein diets were the ones most likely to get liver cancer! They were children of the wealthiest families. P5

[In rat studies] Dietary protein proved to be so powerful in its effect that we could turn on and off cancer growth simply by changing the level of protein consumed… Not all proteins had this effect, cow’s milk protein – casein – promoted all stages of the cancer process. What types didn’t promote cancer, even at high levels? Plant proteins, including wheat and soy. P6

Foci are precursor clusters of cells that can grow into tumors and are predictive of tumor development. By watching foci develop and measuring how many there are and how big they become, we could learn indirectly how tumors develop and what effect protein might have… What we found was truly remarkable. Foci development was almost entirely dependent on how much protein was consumed, regardless of much aflatoxin [carcinogen] was consumed… A principle was being established. Foci development, initially determined by the amount of carcinogen exposure, is actually controlled far more by dietary protein consumed during promotion. Protein during promotion trumps the carcinogen, regardless of initial exposure. P56

The body holds a grudge. If we are exposed in the past to a carcinogen that initiates a bit of cancer that remains dormant, this cancer can still be reawakened by bad nutrition some time later. P57

Foci development only when animals exceeded dietary protein needed (10-12% of caloric intake from protein)… Humans should be getting about 10% of our calories from protein… The average American consumes 15-16% protein. These animal studies hint that it places us at risk for getting cancer. P58

All rats that were administered carcinogen and fed 20% protein of casein either were dead or near death from liver cancer at 100 weeks. All rats given same level of carcinogen but fed the low 5% protein diet were alive, active and thrifty, with sleek coats at 100 weeks. This was a virtual 100 to 0 score, something almost never seen in research. P61

Let there be no doubt: cow’s milk protein [casein] is an exceptionally potent cancer promoter in rats dosed with aflatoxin. The fact that this cancer promotion occurs at dietary levels common in humans (10 to 20%) is provocative… The depth and consistency of these findings strongly suggest that they are relevant to humans for 4 reasons. 1st, rats and human have an almost identical need for protein. 2nd, protein operates in the way for both species. 3rd, the level of protein intake that causes tumor growth is the same level as human’s consume. And 4th, in both species, the initiation stage is far less important than the promotion stage because we are very likely dosed with a certain amount of carcinogens in our everyday lives, but whether we get cancer tumors depends on their promotion or lack thereof. P62, 65

A pattern was beginning to emerge: nutrients from animal based foods increased tumor development while nutrients from plant based foods decreased tumor development. P66

Given that 87% of the Chinese population comes from the same ethnic group – Han, it is more than possible that the majority of the geographic variation in cancer rates is largely due to environment/lifestyle [diet!] not genetics. P71 [This is a key assumption in interpreting the data from the China Study.]

In rural China only 9-10% of the total calories comes from protein, and only 10% of that comes from animal based foods. [That means that only .8% of the calories come from animal protein!] When standardized for body weight, the Chinese ate 25% more calories than their American counterparts, [yet still did not gain weight or suffer from the common diseases prevalent in our society.] Animal protein intake in rural China was only 7.1g/day. In America, it is 70g/day. To put this into perspective, 7g of animal protein is found in just 3 McNuggets. p74, 80

Yes, saturated fat and dietary cholesterol do raise blood cholesterol levels, but did you know that animal protein raises it more effectively? In contrast, plant based foods contain no cholesterol, and in various other ways help to decrease the amount of cholesterol made in the body. P 80

Connection between dietary fat and breast cancer. See charts 4.7-4.9 on pages 84-86. Let me summarize that the higher the intake of fat, and namely animal fat, the higher the incidence of breast cancer. Intake of plant fat has little impact however. Referenced research can be found here (subscription required):
http://www.springerlink.com/content/w7006544030975j6/

Higher dietary fat is associated with higher blood cholesterol and both of these factors, along with higher female hormone levels are associated with more breast cancer and earlier age of menarche [start of menstruation]. P87

Menarche is triggered by the rate of growth of the girl; the faster the growth, the earlier the age of onset. It is also well established that rapid growth of young girls often leads to greater adult body height and more weight and fatness, each of which is associated with higher breast cancer risk… A diet rich in animal based food tends to extend the reproductive life by 9 to 10 years, greatly increasing lifetime exposure to female hormones. [This is in fact compounded by the fact that] higher fat consumption is associated with higher blood levels of estrogen during the critical years of 35 to 45… Thus, a rural Chinese woman’s total estrogen exposure over her lifetime may only be 35 to 40% of the average American woman. P88

Just say no… to meat.
These findings make clear that we should not have our children consume diets high in animal based foods… An interesting implication of this observation, as noted by Ms Gloria Steinem, is that eating the right foods could reduce teenage pregnancy by delaying the age of menarche. P88

At the beginning of the China Study, the prevalent belief was that fiber might prevent colon cancer…As time as gone by, fiber – by itself or as a supplement – has not been proven to provide such a benefit… The China Study did prove however that there is a link between fiber intake and decreased cancer risk and lower cholesterol. But such fiber was consumed as part of a plant based diet. P92 So it may not be the fiber at all that is beneficial, but it was merely correlated with a plant based diet that led to the initial findings of reduced cancer. It is the plants, not the fiber that is the key! Adding fiber supplements to your animal based diet, or consuming heavily processed foods that have added fiber, may not help you!

Why would eating plants help us fend off cancer? Campbell’s theory:
The complex process of photosynthesis uses the sun’s energy to drive the exchange of electrons between molecules in the process of making simple sugars and these into complex carbs, fats, and proteins. Because electrons are the medium of energy transfer for these reactions in the plant, they must be managed carefully just like we must manage energy within a nuclear reactor core. Wild electrons are free radicals and can be very dangerous to the surrounding area. Plants must up a shield around potentially dangerous reactions, and sponge up highly reactive substances that leak out. This shield is made up of anti-oxidants that scavenge up these wild electrons. They are usually colored because the same chemical that sponges up the electron also creates visible colors… What makes this remarkable process relevant for us animals? We produce low levels of free radicals throughout our lifetime simply by being exposed to the sun, radon, pollution, and diet… However, we are not plants, and we don’t build shields to protect ourselves from free radicals. But if we eat plants, fortunately their antioxidants work in our bodies the same way they work in plants. It is a wonderful harmony. The plants even make the antioxidants look appealing with the beautiful, appetizing colors. P93

Diets high in fiber, vitamins C & A have each been linked to lower cancer rates, however isolated supplementation of these items doesn’t lead to lower cancer rates. These nutrients may just be the markers indicating a diet high in plant based foods. The lower cancer rates in turn are not directly due to these nutrients, but rather to the consumption of the whole food. P94

Only 3 vegetables accounted for over ½ of total servings in the American diet: potatoes (mainly as chips and fries); iceberg lettuce; canned tomatoes (ketchup and pizza sauce). Add to that the avg american consumes 32 tablespoons of sugar per day, and it becomes clear that most of our carbohydrates are not complex. P96

Burn baby, burn
Consuming diets high in fats and protein transfer calories away from their conversion into body heat to their storage form as body fat. In contrast, diets low in protein and fat cause calories to be lost as body heat… Chinese consume more calories both because they are more physically active and because their consumption of low fat & protein diets shift conversion of these calories away from body fat to body heat. P101

Eating plants doesn’t mean your kids will be midgets
The good news is that greater plant protein intake was closely linked to greater height and body weight [this linkage is well established with animal protein aleady]. Body growth is linked to protein in general and both animal and plant proteins are effective… These findings support the idea that body stature can be achieved by consuming a low-fat, plant based diet. P103 This is important for growing children especially.

People infected with hepatitis B have an increased risk of liver cancer. Our findings suggested those who were infected and who were eating more animal based foods had higher cholesterol levels and more liver cancer than those infected and not consuming animal based foods. P105

Heart Attack 101
It turns out that if the plaque on the inner wall of the artery accumulates slowly, over several years, blood flow has time to adjust… There will be enough collateral development that blood can still travel throughout the heart. Too much buildup however can cause blood restriction, severe chest pain or angina, but this buildup rarely leads to heart attacks. So what leads to heart attacks? It turns out that less severe accumulations of plaque, blocking under 50% of the artery, that often cause heart attacks. These accumulations have a layer of cells, called a cap, which separates the core of the plaque form the blood. If the cap ruptures, the blood begins to clot around the plaque, blocking the artery in a very short time. This leads to a heart attack. P113

We’ve known this for how long?
In a 1946 study [that no one hears about] 100 heart attack survivors were divided into 2 equal groups. One group was placed onto a restricted animal based food diet, limiting them to 4oz of lean meat per day. All dairy and animal fats were prohibited. The other group was not restricted… After 8 years, only 24% of the control group was alive while 56% of the lean diet group survived. After 12 years, every single control member was dead, but 38% of the diet group was still alive. P118 If you’ve had a heart attack already, can you possibly even think about eating a animal based diet?

You should bypass the bypass
In 1990, there were 380,000 bypass surgeries performed, that means 1 out of 750 Americans had this surgery just in that year alone! [If the rate stays constant, and you assume no repeat surgeries, then 1 out of 75 people will have this surgery over 10 years!!]… 2% of these patients will die because of complications…79% of the patients will suffer cognitive impairment caused by mini-strokes in the brains… Within 3 years of the operation, up to 1/3 of the patients will again suffer chest pain. Within 10 years, 50% of the patients will have died or had a heart attack. And here’s the kicker, bypass patients don’t have fewer heart attacks than those who don’t have the surgery. P124

You won’t believe this.
Cleveland Clinic’s Dr. Esseltyn did a study of 18 heart diseased patients who had suffered through 49 coronary events in the 8 years prior to commencing the study. He placed them onto a very low fat, plant based diet, and prescribed cholesterol lowering medication. At the start of the study, the avg cholesterol level among the 18 was 246. After the study was underway, the avg dropped to 132… In the following 11 years, only 1 coronary event occurred among these 18 patients (and that was from a patient who strayed from the diet for 2 years, but then resumed and suffered no further issues.) Not only has the disease stopped, but it has been reversed. 70% of the patients have seen an opening of their clogged arteries. P127

We’re not normal
Don’t believe me yet? Have you ever known of a person who eats a whole, plant based food diet that is fat or unhealthy? These are rare folks in America, but you can find billions of such people all of over the world who have been eating such a diet for 1000s of years. P 138 It is us who are the aberration.

Eat more, and weigh less.
Studies show that the weight loss effect while adhering to a plant based diet is not due to caloric restriction. These studies have documented that vegetarians consume the amount or more calories than their meat eating counterparts, and yet are still slimmer. P141 You can have your carrot cake, and eat it too!

As complex carb intake goes up and fat intake goes down, the number of deaths from diabetes plummets from 20.4 to 2.9 per 100,000. p149

A study of 25 type 1 and 25 type 2 diabetics was conducted where each group was placed onto a high fiber & carb, low fat diet in a hospital setting. None of these 50 subjects were overweight, and all of them were taking insulin injections. 1 week, he placed all of the patients on to American Diabetes Association diet (which is not much different from a typical American diet unfortunately). He then measured their cholesterol and blood sugar levels after the first week to get a base line. For 3 weeks after this, he placed the subjects onto plant based diet, with only a little lean meat. After 3 weeks, the type 1 patients (who have no ability produce insulin) were able to lower their medication by 40%, and their cholesterol dropped by 30%... Of the 25 type 2 patients, 24 of were able to completely discontinue their insulin medication! P152

Lifetime exposure of estrogen is 2.5 to 3 times higher among Western women when compared to rural Chinese women [because of the later onset of menarche, earlier menopause, and 30% lower estrogen level]… Studies have shown that a mere 17% decrease in estrogen levels could account for a huge difference in breast cancer rates. Imagine, then, what a 26-63% lower blood estrogen level and 9 fewer reproductive years of exposure could mean? P161

Migrant studies show that as people move from a low cancer risk area to a high cancer risk area, they assume an increased risk within 2 generations. This suggests that diet and lifestyle are important causes of cancer… and these rapid changes in cancer rates can’t be possibly explained by changes in inherited genes. P169

Nobody has ever been able to prove that fiber by itself is the magic bullet for preventing colon cancer… However, naturally high fiber containing diets have been proven to prevent colon cancer... In fact if Americans added 13g of fiber from food sources (not supplements or added fiber to processed foods – sorry your super fiber stoked bran flakes don’t count) about 1/3 of colon cancer cases could be avoided. This means that attempts to add isolated fiber to foods may not produce benefits. But consuming plant foods high in fiber is clearly beneficial. P171

Just keep running, and don’t ask any questions.
17 out of 20 studies found that exercise protected against colon cancer. Unfortunately, there seems to be no convincing evidence as to why or how this occurs. P175

Milk. It does a prostate bad.
Men with the highest dairy intake had approximately double the risk of total prostate cancer, and up to a 400% increase in risk of metastatic or fatal cancer. P178

Insulin like growth factor (IGF1) is turning out to be a predictor of cancer just like cholesterol is a predictor for heart disease. Under normal conditions this hormone efficiently manages the rates at which cells grow and reproduce, and how they discard old cells. Under unhealthy conditions, IGF1 becomes more active, increasing birth and growth of new cells, while inhibiting the removal of old ones, both of which favor the development of cancer. So what does this have to do with the food we eat? It turns out that eating animal based foods increases the blood levels of IGF1. p179

Animal protein blocks the production an active (beneficial form) of vitamin D… Persistently high intakes of calcium create an environment that vitamin D cannot be processed by the body. So what food has both animal protein and calcium in abundance, dairy foods. This fits in perfectly with the evidence that links dairy consumption with prostate cancer. Animal protein causes the body to produce more IGF1, stimulating cancer development. Animal protein and calcium prevent vitamin D processing… Persistently low levels of active vitamin D create an inviting environment for different cancers, autoimmune diseases, osteoporosis, and other diseases. P181

The ability of cow’s milk to initiate type 1 diabetes in infants is well documented… A baby is exposed to cow’s milk protein (usually in formula). In the small intestine this protein is only partially digested, leaving fragments intact. The immune system recognizes these fragments as foreign and destroys them. Unfortunately some of the fragments closely resemble the proteins pancreatic cells. The immune system is unable to distinguish amongst these proteins, and ends up also destroying the pancreatic cells. P187

A 1992 study of 142 diabetic children found that every single one had [cow milk protein] antibody levels higher than 3.55. Of the 79 normal children in the study, not a single one had antibody levels this high… This implies 2 things: children with more antibodies consumed more cow’s milk, and second, increased antibodies may cause type 1 diabetes. P188

Could it be genes?
It also been observed that after one member of identical twin pairs gets type 1 diabetes, there is only a 13-33% chance of the 2nd twin getting the disease. If it were all due to genes, then 100% of the 2nd twins should get. In addition, the 13-33% risk of getting the disease is due to the sharing of a common environment and diet, factors that affect both twins, [but not identically it seems]. P190

The American Academy of Pediatrics in 1994 ‘strongly encouraged’ that infants from families with a history of diabetes not be fed cow’s milk for the first 2 years of life. P191

So called controversy based upon studies
In 10 human studies (all case controlled), 5 showed a statistically significant positive association between cow’s milk and type 1 diabetes, and 5 did not. This at first seems to demonstrate considerable uncertainty, but of the 5 studies that didn’t show a positive correlation, not a single one showed that cow’s milk decreased diabetes… Thus, we have 5 that show a positive effect, and 0 that show a negative effect, and 5 with no effect. There is only one chance in 64 that this was a random chance result. P193

A 34 year long study of 144 MS patients divided them into 2 groups; good dieters consumed a low fat diet (less than 20g of saturated fat per day); poor dieters ate a normal diet with more than 20g of saturated fat per day… About 95% of the good dieters remained only mildly disabled for approximately 30 years, and only 5% died. In contrast, 80% of poor dieters died of MS. P196

New studies show that consuming cow’s milk is strongly linked to MS… while the consumption of fish, containing omega-3 fat, was associated with low rates of disease. P197

All autoimmune diseases have been shown to be more common at higher latitudes where there is less constant sunshine. These diseases have a tendency to afflict the same people. [Meaning that the same root cause may be at play across these various autoimmune diseases.]… The consumption of animal based foods, especially milk is associated with greater disease risk. There is evidence that viruses may trigger the onset of several diseases. Binding together these diseases is the evidence that their mechanisms of action have much in common… Is it possible that cow’s milk and lack of sunshine are having a similar effect on MS and other autoimmune diseases because they operate through a similar mechanism?... The idea is not so crazy. This mechanism involves vitamin D. p200

Americans consume more cow’s milk and its products per person that most populations in the world. So Americans should have strong bones right? Wrong! Studies have shown that American women aged 50 and older have one of the highest rates of hip factures in the world. The only countries with higher rates are in Northern Europe and the South Pacific, where they consume even more milk than the US (and where they receive less sunlight). P204

There was 88% less [macular degeneration] for people who ate carotenoid vegetables (spinach, carrots, chard, kale, citrus, etc.) 5 or more times per week when compared to those who ate them once a month… Supplements including vitamins A, C, & E showed little or no beneficial effects. P215

½ of all Americans will have cataracts by age 80… People who consumed the most lutein (from dark, leafy greens) had 50% the rate of cataracts when compared to those who ate the least. P217

Why I haven’t heard this before?
Why do I usually hear the opposite of what you say: that milk and calcium is good for us, that we need meat for protein, and that cancer & heart disease are all in the genes?... Much is governed by the golden rule: he who has the gold, makes the rules. P249

Throwing money down the drain
After 15 years, and 100s of millions dollars, the US Preventive Services Task Force concluded that the evidence is insufficient to recommend for or against the use of supplements A, C, or E; multivitamins with folic acid; or anti-oxidant combinations for the prevention of cancer or cardiovascular disease. P288

When you think of vitamin C, what food source comes to mind first? Did you say oranges or OJ?... You’d be surprised to know that peppers, strawberries, broccoli, peas all have more. Papayas have 4 times as much. P303

Q&A: Tough questions
Could the dietary protein effect be due to other nutrients in the rat diet?
The rats who received less protein were given more carbs in the form of glucose and starch. The extra starch in the low protein could not have been responsible for the lower foci development because these carbs when tested alone actually increase development. If anything the extra carbs in the low protein diet would only increase cancer risk, making the resulting cancer prevention of the low protein diet even more impressive. P351

Might the effects be due to caloric restriction, not low protein?
A review of our many experiments showed that animals fed the low protein diet did not consume fewer calories but, on average, actually consumed more.

Some excerpts from the rebuttal to the China Study:
http://www.cholesterol-and-health.com/Campbell-Masterjohn.html

The China Study looked at cancer in two ways: official cancer mortality statistics and a questionnaire that asked each household whether or not there were cancer patients in the family.

According to the “uncorrected” data, households from villages that had higher average animal protein intakes during the three-day, in-house observation were more likely to have cancer patients within their family according to the questionnaire (Figure 1), but villages with higher average animal protein intakes did not have higher incidences of cancer mortality according to the government statistics (Figure 2).

Yearly meat intake was negatively correlated with cancer whether measured by the official statistics or by the questionnaire, but the association was not statistically significant. [See note 2 on statistical significance.] A much better predictor of cancer by both measures was latitude, which reflects vitamin D levels, but that’s another story for another day.
The only two of these practitioners who to my knowledge have published experimental results with vegan diets are Dr. McDougall and Dr. Esselstyn.
McDougall published the results of a small, uncontrolled intervention trial in which twenty-four rheumatoid arthritis patients consumed a low-fat, vegan diet for four weeks.15 Although there was no control group, measures of arthritis improved in the subjects over the course of the study. The experimental diet was twenty-two percent lower in calories than the basal diet and the subjects lost an average of seven pounds. McDougall therefore had no way to distinguish between the effect of weight loss and the effect of the exclusion of animal products.
Dr. Esselstyn published the results of a five-year intervention with a low-fat vegetarian diet combined with the individualized use of cholesterol-lowering drugs to bring cholesterol down to 150 mg/dL.16 Since Esselstyn considered it unethical to allow patients under his supervision to eat a standard diet, there was no control group. Twenty-two percent of those who began the intervention dropped out of the study within the first two years; thirty-five percent of those who completed it did not submit to the follow-up analysis of their cardiovascular health; of the twenty-two patients who began the trial, only eleven remained in the final analysis. Of these eleven, occlusion of the blood vessels became better in five, stayed the same in one, and became worse in four.

Despite the inconsistent results, the average change in the width of the blood vessels was an increase in 0.08 millimeters. This represents a reversal of atherosclerosis – on average. Likewise, on average, the degree to which blood vessels were constricted decreased by seven percentage points. Six of the eleven dropped out of the study after the first five years; in the following five years, there were ten heart attacks among the six that dropped out while there were none among the five who remained on the program.

Since there was no control group and there was such a high drop-out rate, it is difficult to make much sense of the study. Did the people drop out because their health was not important to them? Or did they drop out because the vegetarian diet made them feel fatigued, unsatisfied, and even less healthy than their original diet full of meat and junk food? Were the people who completed the study but did not submit to the final measurements of their blood vessels reluctant for no reason, or were they reluctant because they were afraid of the results they would obtain based on how the diet made them feel?

The China Study’s questionnaire had no questions specific to the consumption of shellfish (Figure 6). How, then, could anyone possibly draw a conclusion from it about what the optimal amount of animal products are, if the amount needed is so different when the nutrition is supplied by shellfish than when it is supplied by meat?

The questionnaire does not differentiate between fish and shellfish, nor does it ask about the consumption of insects, bones, skin, organ meats, or other foods common in pre-modern diets.
Animal Food Consumption
How often do you usually have fish or sea food in one month? ____ times.
How often do you usually have meat in one month? ____ times.
How often do you usually have eggs in one month? ____ times.
How often do you usually have milk in one month? ____ times.