T.Colin Campbell's Research The China Study
I want to say first I come in peace.
I know Lyle McDonald is one of the most knowledgeable people in nutrition so that is why I ask my question here ( i.e. unbiased scientific information) .
I do not know if this has been addressed specifically so here are my questions:
T. Colin Campbell's China Study - is it scientifically valid that a plant based diet is the way to eat or are there many problems with it? Also Campbell has a problem with too much protein, especially from animal sources. This study is touted as the supreme authority.
I am thinking abut buying "The Protein Book" by Lyle , so that is why I ask this.
So any answers would be appreciated. Thanks
This was posted elsewhere by a good friend of mine who is serious in nutrition. I'm not sure which bits are his and which are from the Amazon review.
But basically what I said above: Cambell mirepresented the true data to push his vegetarian agenda. And epidemiological work tends to be messy for a lot of reasons, why I rarely if ever read it or reference it. Too many confounds and too much direct data to look at instead.
the book claims statistical significance for a lot of the data, where hte actual data doesnt support it...
theres a reason that most of Cambells claims are not published within the peer-review process...
This is another persons review (a subsample of which is on amazon)
Campbell is sadly misinformed when it comes to the topic of protein, something especially regrettable for someone whose "entire professional career in biomedical research has centered on protein". Within minutes of beginning his book, even the dullest reader will quickly realize that Campbell is on a zealous mission against animal protein, which he believes to be public health enemy number one.
Campbell's anti-animal protein bent began while working in the Philippines, where he observed that children from the wealthiest families reportedly ate the most protein and had the highest rates of liver cancer. In itself, this observation is next to useless. Wealthy inhabitants of third world countries are often the first to adapt Western-style diets, which include not just more animal foods but a vast array of nutrient-depleted processed food items loaded with refined flours and sugars. Why blame animal protein--a perfectly natural food for the human species, one that we have been eating with great benefit for our entire 2.4 million+ year history--yet ignore the role of the nutrient-depleted garbage that we only began consuming during the last 150 years? It is the proliferation of the latter--not animal protein--that corresponds with the rise of degenerative diseases in the Western world.
According to Campbell, his protein suspicions were confirmed when Indian researchers found that feeding casein (a type of milk protein) to rats increased their susceptibility to aflatoxin-induced liver cancer. Campbell and his colleagues began replicating these experiments and repeatedly found that casein did indeed trigger cancer in susceptible rodents. According to Campbell, "The safe proteins were from plants, including wheat and soy."
Extrapolating from the deleterious effects demonstrated by casein in rodents, Campbell goes on to warn that all animal proteins are a deadly threat to humans.
Campbell's position constitutes little more than a totally unscientific leap of faith. Casein is one of the major protein-containing fractions of milk; the other is whey. Campbell does not mention that while casein is often observed to promote cancer in rats, whey protein does the exact opposite. Numerous experiments have shown that rats lucky enough to be fed whey experience greatly reduced tumor incidence when compared to rats fed casein, beef, soy or standard rat chow[Badger TM][Hakkak R][Hakkak R][McIntosh GH][Papenburg R][Bounous G].
Preliminary research suggests a similar effect may even occur in humans. A pilot study by researchers at Dalhousie University, Nova Scotia, Canada followed 7 cancer patients who were fed 30 grams of whey protein concentrate daily for six months. Five patients had metastatic carcinoma of the breast, one of the pancreas and one of the liver. Two patients exhibited signs of tumor regression, 2 showed stabilisation of the tumor, while the disease progressed in the remainder but with a trend toward higher lymphocyte glutathione levels. Glutathione is a potent antioxidant and whey consumption has been shown to raise glutathione levels in the body. The researchers concluded that "These results indicate that whey protein concentrate might deplete tumour cells of GSH and render them more vulnerable to chemotherapy."[Kennedy RS]
Whey protein concentrates and isolates are now widely available in health food stores and supermarkets. But nowhere in The China Study does Campbell discuss the potent anti-cancer effects of whey in rats, and nowhere does he call for further research into the promising cancer-fighting benefits of whey in humans. Presumably that would conflict with his rabid venting against animal protein...
Changing the facts
The whey-cancer issue is not the only one in which Campbell deletes inconvenient facts that would dramatically weaken his anti-animal protein hypothesis. After turning the discussion to heart disease, Campbell cites the work of Dr. Lester Morrison, the Los Angeles physician who conducted the earliest clinical trials into the effect of diet on heart disease recurrence.
Morrison took 100 heart attack patients and placed half of on what he himself described as a "high-protein, low-fat" diet and a regimen of nutritional supplements that included calcium, phosphorous, wheat germ, and brewer's yeast. After eight years, thirty-eight of the fifty control patients had died, compared to only twenty-two of the treatment patients[Morrison LM].
To listen to Campbell though, you would think that Morrison's dietary intervention group subsisted on anemic protein intakes. Campbell is quick to point out that Morrison allowed only two ounces of meat for lunch and two ounces at dinner. He further points out that whole eggs and whole dairy were prohibited on the diet. What he doesn't mention--but would full well know seeing that he has obviously read Morrison's papers--is that Morrison also prescribed the consumption of 13 ounces of skim milk daily. Morrison's published "Foods Permitted" list also allowed for "egg whites as desired"[Morrison LM]. Clearly, Morrison's diet was not the very low-protein diet regimen that Campbell would have us believe; in fact, the patients consumed protein levels in excess of the RDA and far greater than the miniscule amounts recommended by Campbell. So why doesn't he just level with us? Is it because he has already spent a good portion of his book dumping on protein and dairy products, and can't bring himself to acknowledge that a diet that prescribed daily milk consumption and relatively high protein levels was successful in reducing heart disease?
Campbell also neglects to mention Morrison's intervention was multi-faceted; it also incorporated overall calorie restriction that resulted in weight loss and the use of nutritional supplements. Excess weight has long been linked to higher rates of CHD, while weight loss has been clinically demonstrated to improve various measures of cardiovascular health. Along with a number of vitamins and minerals, Morrison prescribed supplemental wheat germ and brewer's yeast because of their high B-vitamin content, the latter also containing the important antioxidant mineral selenium. It is now well-recognized that certain B-vitamins lower blood levels of a potentially atherogenic substance known as homocysteine, while a small pilot trial found a marked reduction in mortality among CHD patients taking selenium-rich yeast on a daily basis[Schnyder G][Korpela H].
Maybe Campbell didn't feel the supplements were worthy of mention. After all, despite their clinically-proven effectiveness, Campbell doesn't like nutritional supplements.
Campbell repeatedly pooh-poohs nutritional supplements, insisting they are of little to no value when it comes to improving health and fighting disease.
Of course, denigrating nutritional supplements and recommending a vegan diet, as Campbell does, presents a huge problem--namely, how to get enough B12? After all, animal foods are the only meaningful source of vitamin B12.
Campbell infers that only plants grown on "lifeless" soil lack B12 (actually plants grown in any soil will lack B12, unless they are grown in manure and eaten without washing prior to consumption). Campbell also laments that modern-day vegetables are scoured of all soil before consumption, and thus grudgingly acknowledges that B12 supplements for vegans are a good idea. He also suggests that "..if you never get any sunshine exposure, especially during the winter months, you might want to take a vitamin D supplement"
So this is Campbell's solution to the lack of B12 presented by veganism, a pattern of eating that humans were never meant to follow on a long-term basis: Take B12 supplements...or eat dirt!
Thanks, but no thanks! Better to obtain B12 the way nature intended--from fresh, nutrient-dense meats.
More anti-animal food fanaticism
On page 230, Campbell states in bold type: "There are virtually no nutrients in animal-based foods that are not better provided by plants."
Clearly, Campbell knows little about the nutritional content of animal foods. Animal flesh contains many nutrients that are either found in scarce amounts or entirely absent from plant foods. Here are some examples:
Creatine is used to form adenosine tri-phosphate (ATP), our ultimate source of cellular energy. Creatine availability is critical during situations when neither fat nor glucose can be processed quickly enough to form ATP, such as during the first few seconds of high-intensity physical activities like sprinting and picking up heavy objects. Creatine supplements have been shown in numerous studies to aid performance in power-oriented sports, and to improve muscular strength in patients with congestive heart failure[Kreider RB].
Creatine only occurs naturally in animal foods, with meat by far the richest source. Not surprisingly, habitual vegetarians exhibit poorer creatine status than omnivores[Maughan RJ].
Meat, along with certain species of fish and seafood, is a rich source of taurine, an important amino acid whose concentration in eggs, milk, and plant foods ranges from negligible to none[Laidlow SA][Pasantes-Morales H]. Taurine is found in high concentrations in the heart, brain, and central nervous system, where it helps stabilize the cellular response to nervous stimulation. Taurine possesses antioxidant capabilities and has been shown in double-blind clinical trials to improve cardiac function in patients with congestive heart failure[Schaffer SW][Azuma J][Azuma J].
Taurine cannot be found in plant foods. Humans are able to manufacture their own taurine but with far less efficiency than herbivorous animals, as evidenced by significantly lower blood taurine levels in vegans and rural Mexican women reporting low meat intakes[Laidlaw][Pasantes-Morales H].
Carnitine is a remarkable amino acid that plays a pivotal role in energy production, and is absolutely essential for the fat-burning process to proceed. Because of its pivotal role in energy production, high levels of carnitine are found in the heart and skeletal muscle. Clinical trials have observed markedly improved survival outcomes resulting from carnitine supplementation in patients with heart failure and coronary heart disease[Davini P][Rizos I][Singh RB][Iliceto S]. A review of the scientific literature shows that this versatile amino acid has been shown to benefit anorexia, chronic fatigue syndrome, heart disease, male infertility, sexual dysfunction and depression in aging men, and pregnancy outcomes. Exercise, even at moderate levels, can cause a significant drop in muscle carnitine levels; in patients with angina and respiratory disorders, carnitine enhances exercise tolerance[Kelly GS][Cavallini G][Gentile V].
The richest food source of carnitine, by far and away, is meat. Compared to omnivores, vegetarians repeatedly exhibit lower blood levels of carnitine[Krajcovicova-Kudlackova M][Lombard KA]. Carnitine status appears to also be worsened by the high-carbohydrate diets recommended by folks like Campbell. In healthy men receiving the same amount of dietary carnitine, blood levels of this all-important amino acid rose significantly in individuals following a high-fat, low-carbohydrate diet, while no change in carnitine levels were observed in individuals on a high-carbohydrate, low-fat diet[Cederblad G].
Meat is the only food containing significant amounts of carnosine, an amino acid with some rather interesting and highly beneficial properties[Chan KM]. Carnosine is a potent antioxidant, being particularly effective in protecting cellular fats against free radical damage. Research shows carnosine may accelerate wound healing, boost the immune system, protect against cataracts, reduce gastric ulcer formation, rid the body of toxic metals, and even help fight against cancer[Hipkiss AR]. The most potent effect of carnosine however, appears to be its ability to prevent glycation, which, along with free-radical production, is a major contributor to degenerative illness and the aging process[Price DL, et al].
The potent anti-glycation effects of carnosine may explain why a comparison of vegetarians, vegans and meat-eating omnivores revealed the latter to have significantly lower levels of nasty glycation end-products known as advanced glycosylation end-products (AGEs) circulating in their bloodstreams. The difference could not be explained by total carbohydrate intake, blood sugar, age or kidney function, as all these variables were similar between the vegetarian and omnivorous groups[Sebekova K].
Meat, especially red meat, is the richest source of B-complex vitamins. The B vitamins perform a myriad of crucial functions in the body and requirements for these vital nutrients are dramatically increased during periods of stress, illness and physical activity. Unfortunately, the body cannot store a surplus of B-vitamins for times of increased need, so optimal amounts must be consumed on a daily basis.
Meat, especially red meat, is also a rich source of iron. Iron forms an essential component of hemoglobin, the red pigment in blood that transports oxygen from the lungs to the various body tissues. Insufficient iron intake can result in impaired immune function, decreased athletic performance and lack of energy. A double-blind Swiss study of women aged between 18-55 who had sought medical advice for fatigue, found that most of the women had low blood concentrations of iron. After four weeks, a significantly greater number of women receiving iron supplements reported a decrease in fatigue symptoms than those receiving placebo[Verdon F]. Australian women complaining of fatigue showed similar improvements when treated with either iron supplements or a high-iron diet[Patterson AJ].
Those who need to boost their iron stores should look to red meat rather than supplements or plant foods. When previously sedentary women were challenged with 12 weeks of aerobic exercise, a high meat diet protected iron stores more effectively than iron supplements[RM Lyle]. Heme iron (the form of iron found in meat) is far more easily absorbed by the body than non-heme iron from plant sources. Men and women on lacto-ovo vegetarian diets consistently exhibit lower blood levels of iron, even when consuming similar total amounts of dietary iron as omnivores[Alexander D][Hunt JR].
Animal foods are also by far and away the richest source of zinc. Apart from oysters, meat is the richest source of this mineral, with red meats again containing greater amounts of this mineral than white meats. Zinc is essential for optimal growth and repair, being involved in the actions of several vital hormones and hundreds of enzymatic reactions in the body. Zinc is essential for the formation of superoxide dismutase, one of the body's most potent antioxidants. Zinc deficiencies can result in growth retardation in children, significantly weakened immune function, poor wound healing and muscle loss, lowered testosterone levels and sperm counts, and have also been linked to depression and gastric cancer[Prasad AS][Brown KH][Siklar Z][Dardenne M][Ibs KH][Maes M][Nakaji S][Prasad AS][Hunt CD].
Overt zinc deficiencies are common to Third World countries where animal protein consumption is low. Milder, 'sub-clinical' zinc deficiencies also appear to be a common phenomenon in modernized nations. Those who follow low fat diets are at even greater risk of zinc deficiency[Retzlaff BM][Baghurst KI, et al].
Animal foods, most notably brains and fatty fish, are the only dietary source of long chain omega-3 fats such as DHA and EPA (special algae supplements containing LCPUFA have only recently become available). Some plant foods do contain omega-3 fatty acids, but in a form known as alpha-linolenic acid (ALA). To obtain the LCPUFA the body needs, ALA must be converted endogenously to longer-chain omega-3s such as DHA and EPA. The conversion rate, however, is very low, with clinical studies repeatedly showing that omega-3 fats from plant sources to be vastly inferior to those from animal foods when it comes to boosting long-chain omega-3 status[Fokkema MR][Francois CA][Tang AB, et al].
Numerous studies have shown that vegetarians consume far lower levels of long-chain omega-3 fats--not surprising considering their avoidance of meat and fish[Rosell MR, et al]. Studies of pregnant women show that, compared to omnivores, vegetarians have significantly lower levels of DHA in their breast milk, with vegans displaying the lowest levels of all. These negative fatty acid profiles are reflected in infants, with vegan newborns displaying significantly lower red blood cell levels of DHA. This is an ominous finding, given the critical role that omega-3 fats play in healthy immune function and cognitive development[Williams C][O'Connor DL][Helland IB][Moriguchi T][Dunstan JA].
Along with lowering one's omega-3 levels, low meat intakes also increase the concentration of omega-6 fats inside the body. A high dietary and bodily ratio of omega-6mega-3 fats increases the risk of numerous diseases, including cardiovascular disease. A sizable portion of heart attacks are triggered when blood clots lodge themselves in narrowed coronary arteries and prevent the flow of blood to the heart, a process also known as arterial thrombosis. One of the early and key events in the development of thrombosis is platelet aggregation, the 'clumping together' of blood platelets. Researchers from Melbourne, Australia, compared heavy-meat-eaters, moderate-meat-eaters, lactoovegetarians and vegans and found that as meat consumption increased, platelet aggregation decreased. Heavy-meat-eaters displayed the lowest levels of platelet aggregation, while vegans displayed the highest levels.
While meat eaters ate more of the omega-6 fat arachidonic acid, vegetarians consumed significantly higher concentrations of the omega-6 fat linoleic acid and significantly lower amounts of long chain omega-3's. The resultant unfavorable omega-6mega-3 is believed to be responsible for the higher levels of thromboxane A2 (TXA2) seen in the vegetarian group[Li D]. TXA2 is an eicosanoid that stimulates platelet aggregation. Chilean researchers have similarly observed significantly lower blood levels of EPA and DHA, and concomitant increases in blood platelet aggregation, among vegetarians[Mezzano D]
Plant foods contain all the nutrition that animal foods do? You've got to be joking!
So what about the China Study itself?
Despite it's title, only a small portion of The China Study is actually devoted to discussing the giant epidemiological study of the same name; the rest of the book simply reads like an extended sales brochure for veganism.
Beginning in the early eighties, Campbell was part of a group of Chinese, British and US researchers that presided over the massive epidemiological study known as the China Project, or China Study. The New York Times dubbed it "the Grand Prix of epidemiology," and it gathered data on 367 variables across sixty-five counties and 6,500 adults. After the study data was compiled, the researchers had calculated "more than 8,000 statistically significant associations between lifestyle, diet and disease variables."
According to Campbell, the China Study data showed that: "People who ate the most animal-based foods got the most chronic disease. . . . People who ate the most plant-based foods were the healthiest and tended to avoid chronic disease."[p. 7]
In reality, the China Study showed nothing of the sort.
"The China Study" does not contain the actual data gathered from its namesake study. So when Campbell claims that the China Study found a consistent relationship between animal foods and various diseases, readers have no way of verifying this information for themselves.
Unless of course, they get up off their butts and go retrieve the actual China Study data for themselves. To do this, they will need to check their local libraries (university libraries are the best bet) for a book titled Diet, life-style, and mortality in China: A study of the characteristics of 65 Chinese counties[Chen J]. Once readers have this book in their possession they will quickly discover that there is a galaxy-sized gap between the actual findings of the China Study and the claims made by Campbell in his popular book version.
Let's start with overall mortality, unarguably the most important mortality statistic of all. Animal protein, fish protein, meat intake, saturated fat, and fat calories were all negatively associated with all-cause mortality in infants, children, teenagers and adults, although none of the associations reached statistical significance (for those unfamiliar with research-speak, a negative correlation means that as intake of these foods increased, mortality risk decreased; failure to reach statistical significance means that researchers can't be sure these findings were not due to chance).
Among those aged 0-64, total protein returned a 29% negative association with overall mortality. This finding was statistically significant (p=0.05).
In all age groups, egg consumption was negatively associated with all-cause mortality, with a statistically significant 43% decrease (p=0.01) in overall mortality among those aged 0-64.
No statistically significant relationships, protective or otherwise, were found for milk intake, fiber, cereal grains, legumes, and vegetables among those aged 0-64.
The only other dietary factor that was significantly associated with overall mortality among those aged 0-64 was soy sauce (not soy products), which showed a 43% decrease in mortality risk (p=0.001)
Neither total protein (+12%), animal protein (+3%), fish protein (+7%), plant protein (+12%), meat intake (-20%), saturated fat (+2%), fat calories (-17%), eggs (+19%), nor milk (+6%) demonstrated any statistically significant association with mortality from all cancers. Rice (-26%, p=0.05) and green vegetables (-28%, p=0.05) were statistically associated with reduced cancer mortality, as were the use of alcohol (-27%, p=0.05), home-made cigarettes (-32%, p=0.01), and total tobacco use (-25%, p=0.05).
(Readers can now see why clinical research is superior to epidemiological research--if we were to treat the findings of the China Study proactively, then we would all go out and start drinking and smoking cigarettes in order to improve our odds against cancer! Despite his obvious enthrallment with the results of the China Study, Campbell for some reason doesn't recommend this...)
With regards to specific types of cancer, no statistically significant associations were observed for total protein, animal protein, fish protein, meat intake, milk intake, saturated fat, total fat, fiber, cereal grains, legumes, vegetables and mortality from colorectal or breast cancers.
No statistically significant associations were observed for total protein, animal protein, fish protein, meat intake, milk intake, saturated fat, total fat, fiber, legumes, and mortality from coronary heart disease.
Rice was associated with a statistically significant decrease (-58%, p=0.001) in CHD risk, while wheat flour was associated with a statistically significant increase in CHD risk (+67%, p=0.001). A similar phenomenon was noted for stroke mortality, with a statistically significant risk decrease noted for rice (-44%, p=0.01), and a statistically significant increase in risk observed for wheat flour (+55%, p=0.001) (again, despite his apparent rapture with the China Study results, nowhere does Campbell recommend the avoidance of wheat or wheat flour; in fact, he encourages the consumption of whole grain cereals).
So there you have it...the "Grand Prix" study that supposedly showed "People who ate the most animal-based foods got the most chronic disease. . . . People who ate the most plant-based foods were the healthiest and tended to avoid chronic disease" actually showed that animal-based foods imparted no increased risk of all-cause mortality, cancer deaths, or cardiovascular mortality.
Campbell's lopsided presentation of the facts is most regrettable. Virtually everywhere you turn you'll see or hear underinformed people--who clearly have not taken the time to validate Campbell's claims for themselves--speaking glowingly about this book and notice it's selling well. Like so many people in today's society, these folks are too lazy to think and research for themselves, and are therefore ready prey for misguided "gurus" peddling scientifically unsound nonsense.