Grains vs. Meat
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?
> 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!