Sad news for the Paleo Diet theory:

Even Our Ancestors Never Really Ate the “Paleo Diet”

Excerpt:

“Essentially all of the great apes and their ancestors appeared to have eaten a C3-based diet, consuming fruits, leaves and other plants. Modern humans, on the other hand, rely much more on C4 plants, which include grains like wheat and corn.”

On September 12, a reader commented on a conversation we were having about my post Grains vs. Meat. I was waiting to get some time to properly respond, and I’m glad I did because a review on grains and cardiovascular disease was just published.

Comment:

Sure it’s possible to be healthy and still consume grains. It’s also possible to be healthy and eat doughnuts and drink Pepsi every day, or smoke marijuana every day. That doesn’t mean that doughnuts or marijuana are particularly healthy though. Grains are basically just empty calories, and are basically just less unhealthy versions of cookies. You say that they have beneficial effects on blood sugar, but that’s definitely false. Grains have a huge glycemic load, so their effect on blood sugar is not much better than cookies. And I don’t see why binding to cholesterol in the bloodstream is a good thing, the pregnenolone derived from cholesterol is necessary to create testosterone, so I think dietary cholesterol is very healthy. Considering there’s no connection between dietary cholesterol and cardiovascular disease, decreasing your intake of cholesterol has no benefits. Some people say that grains are a good source of fiber and nutrients, but you’d have to consume a ton of calories from grains to get the same amount of fiber and nutrients that you could get from a small amount of fruits and vegetables. Sure it’s possible to be healthy while consuming grains, but I don’t see why anybody would. They’re just empty calories and are better replaced with protein, fruits, and vegetables.

Response:

A literature review on many of these subjects just came out by Harris and Kris-Etherton, Effects of whole grains on coronary heart disease risk (1). In it, Table 1 lists the benefits that have been found from various whole grains:

Wheat – Improves glycemic control and insulin sensitivity, decreases inflammatory markers, decreases blood pressure

Oats – Lowers LDL and total cholesterol, improves glycemic control and insulin sensitivity, decreases blood pressure

Barley – Lowers LDL and total cholesterol, decreases visceral fat

Rye – Improves glycemic response

> Grains are basically just empty calories,

While I agree with you that there are much more nutrient dense foods than grains, whole grains are not just empty calories. They have small amounts of many nutrients, and some have large amounts of some nutrients. The much maligned corn is quite high in folate and potassium. All whole grains have decent amounts of magnesium (though the fiber and phytate will decrease its absorption somewhat). Barley is a decent source of a range of nutrients.

But even a cup of white spaghetti, while not having many vitamins and minerals without enrichment, has 8 grams of protein along with a lot of slowly absorbed glucose which I personally like before and after a workout.

> And I don’t see why binding to cholesterol in the bloodstream is a good thing, the pregnenolone derived from cholesterol is necessary to create testosterone, so I think dietary cholesterol is very healthy.

Judging by my receding hairline, I don’t know if I need any more testosterone. Seriously, what make you think you need, or can even produce, more testosterone by having more dietary cholesterol?

> Considering there’s no connection between dietary cholesterol and cardiovascular disease, decreasing your intake of cholesterol has no benefits.

Here is what Harris and Kris-Etherton say:

Beta-glucan is a type of viscous fiber in barley and oats that increases fecal loss of bile acids, which are derivatives of cholesterol. About 90% of the bile acids entering the small intestine for fat absorption are reabsorbed in the ileum. Beta-glucan reduces the reabsorption of bile acids, thereby increasing bile acid excretion, lowering the bile acid levels in the liver, and increasing the conversion rate of cholesterol to bile acids. The liver obtains the additional cholesterol by upregulating LDL receptors and increasing LDL particle uptake, thus reducing circulating LDL-C. A viscous fiber intake of 10–25 g/d is recommended by the National Cholesterol Education Program’s Adult Treatment Panel III as an additional diet option to decrease LDL-C. An intake of 5–10 g/d lowers LDL-C by about 5%.

> Sure it’s possible to be healthy and still consume grains.

My point was, if you enjoy eating them and they are not harming your health, then why not do it? And according to the research above (and the research I linked to in my original post), whole grains might help prevent diabetes and heart disease.

1. Harris KA, Kris-Etherton PM. Effects of whole grains on coronary heart disease risk. Curr Atheroscler Rep. 2010 Nov;12(6):368-76.

Question:

I keep hearing this doctor on the radio at 4 a.m. who says that it’s not natural for humans to eat grains (gluten, barley, wheat, oats), that the only thing it’s natural for us to eat is meat. He also tells people not to eat cruciferous vegetables. I know it should be a fairly simple and obvious answer, but I cannot think of a retort to the assertion that humans evolved to eat meat—i.e., cave men chasing down animals and killing them. Because I guess it’s true that people really didn’t start growing grains until fairly late along their evolutionary timeline, right?

Answer:

> He also tells people not to eat cruciferous vegetables.

I haven’t heard that one before.

Saying that humans evolved to do something is attributing intent on the part of the unconscious process of evolution. Humans may have evolved doing something, but that does not mean they should do it or that they will be most healthy or happy by doing it.

While we still do not know everything about nutrition, I tend to think that nutrition science has progressed far enough that there is no need to play it safe by basing our diets on what our prehistoric ancestors might have eaten. We have a pretty good idea of what diets are generally linked to long, healthy lives – much longer lives than those lived by our ancestors.

Tom Billings recently posted a new article to BeyondVeg.com, What is Humanity’s Ancestral (Natural) Diet?. It is very interesting, though it doesn’t talk much about grains.

There is ample evidence that, yes, humans have been eating meat a lot longer than we have been farming grains. That doesn’t mean that humans didn’t eat grains over most of our history, but they probably ate a lot less than we do now. This could also depend on when you consider “human history” to have begun.

It also does not mean that grains are unhealthy or that meat is healthier than grains. To find out about these things, we can look at studies on people who eat more grains versus less. That research looks fairly positive for people who eat more whole grains.

This study found that intake of whole grain cereal was associated with reduced mortality:

Liu S, Sesso HD, Manson JE, Willett WC, Buring JE. Is intake of breakfast cereals related to total and cause-specific mortality in men? Am J Clin Nutr. 2003 Mar;77(3):594-9.

Refined grain cereal did not confer any protection, but also did not increase mortality.

Here is a study showing that whole grains were linked to lower rates of type 2 diabetes:

de Munter JS, Hu FB, Spiegelman D, Franz M, van Dam RM. Whole grain, bran, and germ intake and risk of type 2 diabetes: a prospective cohort study and systematic review. PLoS Med. 2007 Aug;4(8):e261.

On the other hand, I’ve never seen a study linking meat from birds or mammals to a lower risk of mortality or type 2 diabetes.

Disease Rates of Vegetarians and Vegans summarizes the studies that have compared vegetarians’ mortality rates to non-vegetarians. No study has shown regular meat-eaters to have a lower mortality rate than vegetarians. Pesco vegetarians and lacto-ovo vegetarians had lower mortality rates than regular meat-eaters.

That is not to say that someone cannot eat large amounts of meat and no grains and still be healthy. But, in my opinion, such a person is taking more of a chance with their health than people eating more whole grains and less meat.

Finally, I would like to end by pointing out how much I appreciate my prehistoric ancestors’ suffering through their “solitary, poor, nasty, brutish and short” lives so that one day I could comfortably eat a delicious bowl of pesto pasta made from domesticated grains and herbs, while watching The Colbert Report on my computer. We’ve come a long way since our days as hunter-gatherers!