More Thoughts on The China Study

If there’s a definition of irony, eating peanut butter and cream cheese on a Wasa Fiber Rye while reading Colin Campbell must be it.

OK, you only get the irony if you’ve read Campbell.  He did a bunch of experiments where he fed aflatoxin (a fungal toxin and known carcinogen sometimes found in peanuts) to rats.  The aflatoxin-dosed rats who also had casein, a milk protein, added to their rat chow all died of liver cancer, while the aflatoxin dosed rats who did not have casein added to their rat chow did not die of liver cancer.

I must admit, this gave me pause.  I looked at my half-eaten snack and wondered how my ol’ liver was doing.

Campbell’s book is fascinating, but he tries my patience.  If I had a dollar for every time he notes a correlation and then says, “From this we can conclude that A causes B,” I would be a very wealthy woman.  If I had another dollar for every time he says, “A Western diet high in meat and refined carbohydrate causes <insert name of evil disease here>,” I would be obscenely, filthily wealthy, rolling around naked in piles of dollar bills every day instead of going to work.

(Oh, excuse me, did I say naked?  No, no, rolling around fully, decently clothed in piles of dollar bills, of course.  This is a PG-13 blog.  Most of the time.)

High in meat and refined carbohydrate.  As if the two were inseparable!  What about diets high in meat and low in refined carbohydrate?

Finally, and this one goes beyond annoyance into the realm of hurt - he refers to the late Dr. Robert Atkins as “an obese snake oil salesman with high blood pressure.”  I am so sick of the accusation that poor Dr. Atkins, suffering from edema due to treatment for the head injury which killed him, was “obese.”

I understand that nutrition inspires the kind of passionate debate usually reserved for things like religion, politics, and the Red Sox-Yankee game.  But could we please try to avoid hitting below the belt, distorting facts about people’s personal lives, and otherwise behaving like an ass?  (Oh, wait, is that hitting below the belt?)

I still don’t know about cancer, but after reading Campbell’s distorted description of Dr. Atkins, and seeing how he muddies correlation with causation, and how he lumps meat and sugar together as if they are inseparable, I have to wonder what other facts he’s playing fast and loose with.  Maybe he’s right; maybe he’s wrong.  Should I eat peanut butter and dairy products together?  Who the heck knows?

But I can say that he’s flat out wrong about diabetes.  He claims it is caused by high consumption of animal protein and animal fat.

(Dan, if you’re reading this, try not to snort coffee through your nose onto your keyboard, hon, OK?  Cause that hurts.)

This is particularly ironic because Campbell does a very good job early in the book of explaining the difference between correlation and causation.  He says that people in countries have more telephone poles have more heart disease, but you can’t conclude from this that telephone poles cause heart disease.  One thing that’s required to convert correlation to causality is the ability to suggest a mechanism by which one thing causes another, and that is missing with the telephone poles-heart disease correlation.

So, pray tell, what is the mechanism by which excessive consumption of either animal protein or animal fat might cause diabetes?

Hello?  I’m waiting …

So, there might be a correlation between animal product consumption and diabetes, but without that mechanism, it’s gonna be hard to show causation.

Meanwhile, there is also a correlation between carbohydrate consumption and diabetes, and there is a mechanism that explains it:  carbohydrate consumption leads to an insulin response; excessive carbs mean excessive insulin; after a while the insulin receptors in the cell wear out, leading to higher blood sugar; pancreatic beta cells try to compensate by producing more insulin, while at the same time, chronic high blood sugar causes more beta cells to die.  Where does excessive consumption of protein and fat fit into all this?

Other things that maddened me:

• Campbell notes, quite rightly, that in spite of the mainstream medical position that cholesterol levels above 200 (or is it 180 now? they keep lowering it) are a risk factor for heart disease, about one half of all heart attacks occur in people with cholesterol between 150 and 200.  Since the all-cause death rate starts to rise when cholesterol levels fall below 170, a sane person might conclude that a) cholesterol levels are not an accurate predictor of heart disease risk, and b) one should not aim to lower cholesterol levels excessively.  Campbell, however, fails to mention the all-cause death rate, which enables him to conclude that we are not lowering our cholesterol enough, and recommends that we try to get our cholesterol lower than 150.
• Campbell discusses vitamin D synthesis at length, stating that vitamin D is produced when sunlight acts on a precursor substance in the skin.  He does not once name that precursor substance, which is, of course cholesterol.  Why doesn’t he mention this?  Could it be because for Campbell cholesterol is the antichrist?

I don’t know if I have the patience to finish this book.  Campbell has some good things to say.  He’s absolutely right that the standard American diet is what’s killing us.  I’ll give him the benefit of the doubt that he himself is as healthy as he claims to be.  I’ll grant that vegetarians and vegans who eat whole foods are healthier than people who eat the standard American diet.  But because the standard American diet conflates so many other factors with meat eating, how can you tease out whether it’s the meat or the sugar or the artificial flavors or the fluoride in the drinking water or what?