Is the Popular 'Paleo Diet' a Bunch of Baloney?
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True – but why not simply tell people to eat whole grains instead of refined ones?
Cordain adds a concern about gluten-containing grains (wheat, rye and barley) because they cannot be eaten by the small percent of the U.S. population that suffers from celiac disease or the slightly larger group of Americans with gluten allergies or sensitivities. Well, it makes sense that those with celiac disease or allergies should avoid gluten, but why does that mean we all should?
How about dairy? In his book The Paleo Diet Revised, Cordain explains the dairy prohibition, saying, “Paleolithic people ate no dairy foods. Imagine how difficult it would be to milk a wild animal, even if you could somehow manage to catch one.” Good point, but early humans did consume dairy in the same way all mammals do. Human infants drank breast milk. Humans did evolve to consume and digest dairy as infants.
After weaning, Paleolithic humans had no reason to continue producing lactase, the enzyme needed to digest lactose. But sometime after the emergence of agriculture, after humans domesticated livestock, some humans were born with a genetic mutation allowing them to continue producing lactase after weaning, into adulthood.
Milton calls this “a classic case of how human culture modifies their environment and then humans adapt to their own changes in the environment.” First, humans domesticated livestock, and then any individuals with the genetic mutation allowing them to digest dairy as adults had an advantage over those who did not.
She notes that whereas some societies with livestock evolved adult lactase secretion, others used technology instead of genes to consume dairy products. “They figured out a way to get the lactose to be eaten by bacteria or drained out -- maybe they made a yogurt or something like that -- and then they eat the material that remains and it isn't full of lactose anymore.”
Cordain acknowledges that some 35 percent of the world’s population can digest lactose into adulthood, but points to dairy as the cause of cancer risks, insulin resistance, and acne. A recent study did find a link between high-fat dairy and mortality from breast cancer, but it recommends replacing high-fat dairy products with lowfat or nonfat ones, not cutting dairy out entirely.
What about the paleo diet’s claim that one must eat meat? In his book The Paleo Solution, Robb Wolf writes, “Your protein source needs to have the following criteria:
1. It needs a face.
2. It needs a soul.
3. You need to kill it, and bring its essence into your being.
Cordain gives vegetarians the bad news a bit more gently, but the data he cites does not back up his assertions. In fact, one study he names backs up the health benefits of a vegetarian diet.
“Ancestral hunter-gatherer diets were never vegetarian,” Cordain notes – perhaps correctly. But he goes on to claim, “If they were, these diets would have been rapidly culled by natural selection because they are eventually lethal. Humans require vitamin B12 which is not found in plants, but only in animal foods.”
It’s true that humans require vitamin B12, which is only found in animal foods – but vegetarians do eat animal foods in the form of dairy and eggs. It’s vegans who eschew all animal foods, not vegetarians.
Cordain cites two studies that found that vegetarian diets are not more healthful than omnivorous ones. The first was an Oxford University study published in 1999. Cordain quotes the study’s abstract, which reads, “There were no significant differences between vegetarians and nonvegetarians in mortality from cerebrovascular disease, stomach cancer, colorectal cancer, lung cancer, breast cancer, prostate cancer, or all other causes combined.”