Spinning Facts to Fit Biases

Hi Loren,

I was hoping I could induce you to correct a statement made about your work in a recent post in The Atlantic. It’s by a senior editor, a medical doctor, James Hamblin, who’s doing a take-down of Perlmutter’s Grain Brain couched as a piece of journalism. In it he quotes David Katz of Yale, commenting about the paleolithic diet and your work.

I thought perhaps you could take a little time to set both Hamblin and maybe even Katz right. The key section:

“Of course,” Katz added, “Everything about the Paleolithic Era is subject to debate. Most of us don’t know what we had for breakfast yesterday, let alone what people were doing 100,000 years ago. Yeah, I’ve read the same thing that the average life expectancy was between 20 and 40 and, consequently, the diseases of old age didn’t happen because old age didn’t happen. There’s nothing about their diet that we know to be protective against things like Alzheimer’s. That’s just silly.”

Perlmutter has estimated that the Stone Age diet was 75 percent fat, a claim Katz finds “wildly preposterous.” Anthropological research, he pointed out the work of Loren Cordain, suggests that in the age before cooking oil, humans ate mostly plants with a scattering of seeds and nuts. “Virtually nothing in the natural world is that concentrated of a fat source, except maybe for the brain. Maybe if they just ate the brains of animals? They didn’t have oil. They only started adding oil to the diet after the Dawn of Agriculture. What the hell could they possibly have eaten that would be that fatty?’”

This kind of journalism is bad enough when they get the facts vaguely right and just spin them to fit their biases. When they butcher the facts, too, it deserves correcting.

All the best,

Gary Taubes

Gary Taubes is the author of Why We Get Fat (2011), Nobel Dreams (1987), Bad Science: The Short Life and Weird Times of Cold Fusion (1993), and Good Calories, Bad Calories (2007), which is titled The Diet Delusion in the UK. He has won the Science in Society Award of the National Association of Science Writers three times and was awarded an MIT Knight Science Journalism Fellowship. Taubes studied applied physics at Harvard and aerospace engineering at Stanford (MS, 1978). Taubes has written numerous articles for Discover, Science and other magazines. Originally focusing on physics issues, his interests have more recently turned to medicine and nutrition.

Dr. Cordain’s Response:

Hi Gary,

Good to hear from you. Thanks for forwarding me the article from The Atlantic by James Hamblin, MD. I came away with a number of impressions:

1. Both Katz and Perlmutter acknowledge the underlying, evolutionary basis for human nutrition.

2. Scientists involved in gluten research and Paleo Diets (including myself) were not directly interviewed in this article. This omission likely fuels Hamblin’s perspective and does not provide equal input for both sides of the argument.

3. I was not interviewed for this article and the quote you cite below is not mine, but rather appears to be David Katz’s interpretation of our work. The quote is erroneous as well as being just flat out wrong. Our group has repeatedly analyzed the composition and macronutrient content of historically studied hunter gatherer diets.^1-7Animal fat has been an integral part of hominid diets since the origins of our genus Homo. To correct whomever wrote the erroneous quote below, regardless of whether fat comes from either plant or animal food sources, it contains identical caloric densities (9 kcal/g). In the typical hunter gatherer diet, animal fat would have generally exceeded plant fat on an average daily basis.

Brain contains virtually no fat, but rather is comprised primarily of fatty acids bound to the phospholipid fraction. A fat (triglyceride) is also technically called an acylglycerol (a glycerol molecule bound to a fatty acid [acyl group] via an ester bond). Brain contains little or no acylglycerol, but rather structural fatty acids found not in the triglyceride fraction, but in the phospholipids fraction. There is no doubt that brain, marrow and other fatty (and fatty acid) portions of wild animal carcasses would have been preferred by our hunter gatherer ancestors over lean meats.

Cordially,

Loren Cordain, Ph.D., Professor

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