The slam-dunking of "The China Study"

Thanks to Richard at Free the Animal for the tip-off, I have just completed reading the most incredibly well written, well-balanced and systematical analysis of a nutrition study - ever!

Written by Denise Minger, (an ex-vegan who apparently enjoys number-crunching in her spare time) this is an absolute must read! Her writing style is very engaging and often entertaining. Just out of her own curiosity, she took the source data that T. Colin Campbell used for his book "The China Study", cut the data herself and made her own un-biassed deductions, and in the process effectively ripped Mr Cambpell a new one.

Most importantly, she has produced possibly the most important document relating to nutrition in recent times (possibly rivalling Gary Taube's seminal New York Times article "What if it's all been a big fat lie?"). She dismantles the entire "China Study" with one arm behind her back and reduces T. Colin Cambpell to a blubbering and jibbering mess.

It's a hard slog, but well worth the read. Here are my favourite snippets:

• http://rawfoodsos.com/2010/07/07/the-china-study-fact-or-fallac

  • Notice Campbell cites a chain of three variables: Cancer associates with cholesterol, cholesterol associates with animal protein, and therefore we infer that animal protein associates with cancer. Or from another angle: Cancer associates with cholesterol, cholesterol negatively associates with plant protein, and therefore we infer plant protein protects against cancer.

    But when we actually track down the direct correlation between animal protein and cancer, there is no statistically significant positive trend. None.

  • the only way Campbell could indict animal protein is by throwing a third variable—cholesterol—into the mix.
  • In other words, it looks like animal foods have virtually no effect—whether positive or negative—on the occurrence of liver cancer in hepatitis-B infected areas.
  • In the high-risk groups, the correlation between total cholesterol and liver cancer drops from +37 to +8. Still slightly positive, but not exactly damning.
  • Campbell’s implication that green vegetables are associated with less cardiovascular disease is misleading.
  • Since only frequency and not actual quantity of greens seems protective of heart disease and stroke, it’s safe to say that greens probably aren’t the true protective factor.
  • Check that out! Fish protein looks weakly protective all-around; non-fish animal protein is neutral for coronary heart disease/heart attacks and stroke but associates positively with hypertensive heart disease (related to high blood pressure); and plant protein actually correlates fairly strongly with heart attacks and coronary heart disease.

  • If you’re wondering about the connection between animal protein and hypertensive heart disease, by the way, it’s actually hiked up solely by the dairy variable. Here are the individual correlations between specific animal foods and hypertensive heart disease:

    Milk and dairy products intake: +30** Egg intake: -28 Meat intake: -4 Fish intake: -14

  • In addition to greater rates of hepatitis B infection, higher-cholesterol areas had additional risk factors for liver cancer, such beer consumption, which also inflated the trend. Despite Campbell’s claims, cholesterol itself does not appear to significantly heighten cancer rates in at-risk populations.

  • Perhaps more troubling than the distorted facts in “The China Study” are the details Campbell leaves out.

    Why does Campbell indict animal foods in cardiovascular disease (correlation of +1 for animal protein and -11 for fish protein), yet fail to mention that wheat flour has a correlation of +67 with heart attacks and coronary heart disease, and plant protein correlates at +25 with these conditions?

    Speaking of wheat, why doesn’t Campbell also note the astronomical correlations wheat flour has with various diseases: +46 with cervix cancer, +54 with hypertensive heart disease, +47 with stroke, +41 with diseases of the blood and blood-forming organs, and the aforementioned +67 with myocardial infarction and coronary heart disease? (None of these correlations appear to be tangled with any risk-heightening variables, either.)

  • Campbell extrapolates this research beyond its logical scope: He concludes that all forms of animal protein have similar cancer-promoting properties in humans, and we’re therefore better off as vegans. This claim rests on several unproven assumptions:

    1. The casein-cancer mechanism behaves the same way in humans as in lab rats.
    2. Casein promotes cancer not just when isolated, but also when occurring in its natural food form (in a matrix of other milk substances like whey, bioactive peptides, conjugated linoleic acid, minerals, and vitamins, some of which appear to have anti-cancer properties).
    3. There are no differences between casein and other types of animal protein that could impose different effects on cancer growth/tumorigenesis.
  • The rats in Campbell’s research consumed casein as their only protein source, the equivalent of someone eating zero plant protein for life. An unlikely scenario, to be sure.
  • Also, it seems Campbell never mentions an obvious implication of a casein-cancer connection in humans: breast milk, which contains high levels of casein. Should women stop breastfeeding to reduce their children’s exposure to casein? Did nature really muck it up that much? Are children who are weaned later in life at increased risk for cancer, due to a longer exposure time the casein in their mothers’ milk? It does seem strange that casein, a substance universally consumed by young mammals, is so hazardous for health—especially since it’s designed for a time in life when the immune system is still fragile and developing.
  • In sum, “The China Study” is a compelling collection of carefully chosen data. Unfortunately for both health seekers and the scientific community, Campbell appears to exclude relevant information when it indicts plant foods as causative of disease, or when it shows potential benefits for animal products. This presents readers with a strongly misleading interpretation of the original China Study data, as well as a slanted perspective of nutritional research from other arenas (including some that Campbell himself conducted).
  • It’s no surprise “The China Study” has been so widely embraced within the vegan and vegetarian community: It says point-blank what any vegan wants to hear—that there’s scientific rationale for avoiding all animal foods.

Posted from Diigo.