The China Study seems to be referenced just about everyday lately by a fitness or nutrition professional. Usually these people are telling you to avoid animal products all together, that being vegetarian is the healthiest way to eat to avoid degenerative diseases and that animal protein will straight up kill you.
First off, let me explain The China Study to those who have not read it, and for full disclosure neither have I, though it is on my short list. According to wikipedia:
The China Study is a 2005 book by T. Colin Campbell, Ph.D., and his son, Thomas M. Campbell II. Dr. Campbell is a professor of Nutritional Biochemistry at Cornell University and one of the directors of the China Project.
The book examines the relationship between the consumption of animal products and illnesses such as cancers of the breast, prostate, and large bowel, diabetes, coronary heart disease, obesity, autoimmune disease, osteoporosis, degenerative brain disease, and macular degeneration. “The China Study,” referred to in the title is the China Project, a “survey of death rates for twelve different kinds of cancer for more than 2,400 counties and 880 million (96%) of their citizens” conducted jointly by Cornell University, Oxford University, and the Chinese Academy of Preventive Medicine over the course of twenty years.
The authors introduce and explain the conclusions of scientific studies, which have correlated animal-based diets with disease. The authors conclude that diets high in animal protein (including casein in cow’s milk) are strongly linked to diseases such as heart disease, cancer, and Type 2 diabetes.
The authors recommend that people eat a whole food, plant-based diet and avoid consuming beef, poultry, and milk as a means to minimize and/or reverse the development of chronic disease. The authors also recommend that people take in adequate amounts of sunshine in order to maintain sufficient levels of Vitamin D and consider taking dietary supplements of vitamin B12. The authors criticize “low carb” diets (such as the Atkins diet), which include restrictions on the percentage of calories derived from complex carbohydrates.
You might notice some key words in that paragraph, like correlated. Correlation does not equal causation. This is an incredibly important quote to understand. As has been pointed out before by others, there has been correlational research that shows that people who shave the least are the most likely to get heart disease. So does this mean that lack of shaving causes heart disease? No it merely means that people who do not shave maybe care less about their appearance, and maybe about their health or a whole host of their variables, the actual lack of shaving is not the cause of heart disease.
In this China Study there was some work done on rats in which they fed them 20% of their calories from casein (the major protein in dairy). This caused an increased mortality rate, and an increase in degenerative diseases. This is concerning, no question, and one reason why I only recommend whey protein powder to clients, I cover more of this particular topic HERE.
But who actually takes in 20% of their calories from casein, do you know how much dairy that is? Lets say you take in 2,000 calories per day, 20% of that is 400 calories, or 100 grams of casein! Since milk protein is about 80% casein, and their is 1 gram of protein per ounce of milk, so about .8 grams of casein per ounce of milk. That would require 125 ounces of milk to get 100 grams of casein! That is almost 16 cups! Sure some of that casein can come from cheese, yogurt and protein powder, regardless that would take an inordinate amount of milk.
The point I am making is that maybe too much casein can be problematic, but lets not get ahead of ourselves. No one I know is recommending or consuming 16 glasses of milk per day! That same study showed that when rats were fed 5% of their calories from casein, they were free of disease and had longer life expectancies. That gives us 25 grams of casein per day, which is like 4 cups of milk per day. That seems reasonable. For more info on milk consumption and recommendations, read THIS.
To continue some of the misconstrued data:
The authors state that “several studies have now shown, in both experimental animals and in humans, that consuming animal-based protein increases blood cholesterol levels. 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.”
The authors also state that “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 grams per day whereas Americans average 70 grams per day.”
The authors conclude that “the findings from the China Study indicate that the lower the percentage of animal-based foods that are consumed, the greater the health benefits-even when that percentage declines from 10% to 0% of calories. So it’s not unreasonable to assume that the optimum percentage of animal-based products is zero, at least for anyone with a predisposition for a degenerative disease.”
This is complete and utter crap. Just stop and think critically about those statements for a minute. Think of everything you have seen me blog recently about cholesterol and its minimal role in health problems. That saturated fat and cholesterol raise blood cholesterol significantly? I think not. Maybe in rabbits, but they are vegetarians! Claiming that animal protein is the single greatest cause of increased cholesterol is just plain false. Find me some peer-reviewed double-blind placebo controlled studies repeatedly showing that, then you maybe have something to hang your hat on, otherwise that is ridiculous.
Using the word association again means very little. Correlation does not equal causation. There could be a million other variables in play here. These rural Chinese also most likely eat less sugar, less refined flour, less trans-fats, less McDonald’s, are more active, get more sleep, get more sunshine, have stronger community relationships, want me to keep going? Just looking at simple associations tells us little to nothing! It is not indicative of cause!
The human species has been consuming animal protein throughout its existence. The Inuit have been living on a mainly meat-based diet for thousands of years and yet they are free of modern degenerative diseases, consuming little to no vegetable foods. The Masai of Kenya live mainly on their cattle, the meat, blood and milk. That is the great bulk of their food intake, and yet they too are free of modern degenerative diseases. In his masterpiece, Nutrition and Physical Degeneration, Weston Price travels the world looking at isolated populations eating their indigenous diets. In every case when people were eating real food, including plenty of animal protein, these people were incredibly healthy, only when they replaced these foods with refined flour and sugar did the signs of degenerative diseases manifest.
He saw dairy-based diets where people were long-lived and sturdy (maybe because their cows ate grass, got sunshine and exercise, were only milked at certain times of the year, and the milk was not skimmed nor pasteurized, just a thought), meat-based diets, vegetable based diets, real food, and all these people were healthy. They were all in good physical condition, free of dental caries, resistant to tuberculosis, and free of heart disease, cancer, diabetes and other diseases of civilization. That is until they were exposed to unrefined flour and sugar, and then the story changed.
The China Study may have some relevance, and it might make some good points, but telling people that dropping animal foods altogether is the healthiest course of action is a fallacy. Animal foods are high in fat soluble vitamins, are the only available food source of vitamin D, and are a great source of vitamin B12 that the plant-based foods lack. It has been shown throughout history and evolution that humans have eaten plenty of animal products without harm.The difference is these animals were from an unpolluted world, free from synthetic hormones, antibiotics, corn-based diets, antibiotic-resistant bacteria, etc. Maybe that is the problem, and not animal protein itself, since we have been consuming it in fair amounts for hundreds of thousands of years.
Don’t throw the baby out with the bath water. Don’t take one thing and make it another, extrapolating it to apply generally across the board. That is crappy science that does nothing to advance the field of nutrition, and in fact only holds us back from discovering real information. While I am certainly not suggesting that anyone eat a meat-only diet, dropping animal products down to 0% is not warranted either. Eat real food. Eat a nice blend of grass-fed or pastured animals, lots of veggies, some fruits, a few high quality grains and plenty of healthy fats and you will be incredibly healthy.
