Yours and Maelán Fontes Villalba’s position is both convincing and very interesting. But you agree that there are also studies showing protective effect of whole-grains?
I have another hypothesis – maybe complementary to yours: Perhaps it is before all drastic technological treatments applied to raw food edible materials that have rendered them deleterious for health via modified compounds not adapted to our genetics. Otherwise, our ancestors had a very low life expectancy: this an important point. And, if cereal grains were so bad, why are they edible? Don’t forget also that we have to consider wholegrains in the context of a whole diet. Finally, our ancestors seemed to eat lots of meat: maybe they were submitted to acidosis? And what do we know about diet-related chronic diseases at this ancient periods?
However, your genetic argument remains strong, I agree.
Anthony FARDET, Ph.D.
Chargé de Recherches (Research scientist)
Human Nutrition Research Center, Auvergne
Clermont-Ferrand/Theix Research Center
Dr. Cordain’s Response
Dear Dr. Fardet,
Thank you for keeping an open scientific mind — in regard to your comments, it is ironic that the range of diets to which our species has been conditioned to over the vast expanse of evolutionary experience is now beyond the reach of many of the world’s people.
France and French people have developed a cultural tradition of foods and eating/lifestyle habits which on the surface (in large population studies) appear to be healthier than in many parts of Europe and in the rest of the world. In France, on a population wide basis, French bread and other forms of wheat are consumed daily, as is wine, cultured cheese, and butter. Let’s not forget fresh veggies, fruit, fish, olives and olive oils — particularly in the South of France. Moreover, American style fast food is typically shunned by at least the older French population. Additionally, meals are consumed over long time periods with multiple dishes consumed in relaxed settings. These dietary patterns typically result in reduced total caloric intakes over a 24 hour period. This manner of meals pretty much describes the Mediterranean Diet which likely is healthier than the typical US Diet or the typical non-Mediterranean European Diet — both of which appear to accelerate all chronic diseases of western civilization.
Could the French or Mediterranean Diet be the healthiest way to stave off the chronic diseases which impact most western societies or is there a healthier alternative? Contrast the Mediterranean Diet and its associated morbidity and mortality rates for all causes combined to the Japanese Diet, or better yet to contemporary Paleo Diets. We now have preliminary data that the Paleo Diet is more nutritionally dense than the Mediterranean Diet and maintains multiple nutritional characteristics superior to the French, Mediterranean or Japanese Diets. The therapeutic data for contemporary Paleo Diets is now available. You can find these studies if you diligently look for them on MEDLINE.
Let me now address a few other concerns you have offered:
1. “Otherwise, our ancestors had a very low life expectancy: this an important point.”
Although this issue may represent an intuitive “flash point,” the best and most correct data would suggest otherwise. First, your characterization that, “our ancestors had a very low life expectancy” is not necessarily correct and is moreover misleading. Let me give you a simple example. If we have a population of 4 people (2 adults who die at age 80 and who give birth to 2 children who die in childbirth), then the average life expectancy of this population is quite low (160 years/4 = 40 years). Hence, “average lifespan” really only represents the average age at death. What is more important is to characterize the “average age” of the entire living population.
These statistics are calculated regularly by life insurance companies in the western world and are called Life Tables. Life Tables therefore reflect the living population and not those who have died only compared to the living. At least 4 life table studies of hunter gatherers show that a good percentage of the population survives into old age (>60 yrs.). These facts are rather surprising given that in their world, there was no modern medicine, sanitation or contemporary health practices, and that mortality comes not from chronic diseases (as in the western world) but rather from accidents, trauma, snake bikes, warfare and the stresses of living outdoors for an entire lifetime. Mortality and morbidity among hunter gatherers (even the elderly) do not show them sufferings the signs or symptoms of chronic disease found in western populations, and this should be the take home point. Let’s adopt the best of their worlds — leave the worst behind and take the best that the modern world has to offer.
2.”If cereal grains were so bad, why are they edible?”
Again, I encourage you to read my paper, “Cereal Grains: Humanity’s Double Edged Sword’ — Cordain, L. Cereal Grains: Humanity’s Double Edged Sword. World Rev Nutr Diet. Basel, Karger, 1999, vol 84, pp 19–73.
Cereal grains (whole wheat, rye, barley, oats, corn, maize, sorghum, millet, etc.) are not generally edible (or very poorly digestible) by humans (or almost any other primate) in their natural state without cooking. As a species, we have a poor/limited ability to hydrolyze raw grain starches into sugars and metabolize them and degrade their raw proteins into amino acids in our guts for absorption. Hence whole, uncooked grains consumed by humans and by virtually all primates (except for a single species of baboon [Gelada]) represent a food source which was rarely or never never consumed. See my paper cited above for the scientific references.
Accordingly, until humans developed fire, cereal grains would have never been a significant food source. More importantly, the ability to start fires “at will” is the crucial issue here. This technology likely developed in Europe (only) about 300,000 to 250,000 years ago, but occurred not “at will”, but more likely by collecting natural and lightning caused fires. To star a fire “at will” results from 4 or 5 technological advances which probably occurred only after the appearance of behaviorally modern humans (~200,000 ago or less).
More importantly, the cell walls of cereal grains must be broken down by mechanical means (milling) before fire and heating are effective to hydrolyze cereal grain starches and thereby make them available for human nutritional absorption. Important in this concept is that the first crude cereal milling stones do not appear in the archaeological record until about 15,000-25.000 years ago in the mid-east. The fossil, nutritional and physiological data indicate that cereal grains would have been rarely or never used as food sources by our species until very recently in human evolution, simply because they were indigestible.
3. “Don’t forget also that we have to consider whole-grains in the context of a whole diet.”
Consider reading these two papers:
2. Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O’Keefe JH, Brand-Miller J. Origins and evolution of the western diet: Health implications for the 21st century. Am J Clin Nutr 2005;81:341-54
When cereal grains displace lean meats, fish, seafood, eggs, organ meats, fresh vegetables, and fresh fruits, they dilute the trace nutrient (vitamin, mineral, phytochemical) concentration of the 13 nutrients most lacking in the typical western diet. Hence, in the context of a whole diet, the inclusion of cereal grains makes all nutritional considerations worse.
4. “Finally, our ancestors seemed to eat lots of meat: maybe they were submitted to acidosis?”
The available archeaological evidence worldwide, spanning hundreds of thousands of years shows that osteological (bone mineral abnormalities) evidence cannot support your supposition. Rather, osteoporosis, cribra orbitalia and other bone mineral pathologies stemming from dietary induced acidosis only became commonplace following the agricultural revolution and the adoption of cereal grains and plant foods as staples. The physiological and archaeological mechanisms and arguments for these events are fully outlined in my paper, Cereal Grains: Humanity’s Double Edged Sword.
5. “And what do we know about diet-related chronic diseases at this ancient periods?”
As I have pointed out in prior blogs, it is difficult to deduce heart disease from the fossil/bone record. Further, except for bone cancers, the same be held true for cancers. Nevertheless, bone cancers are extremely rare or non-existent in the archaeological human record prior to agriculture. Studies of historically studied hunter gatherers show cardiovascular disease to be rare or non-existent.
Loren Cordain, Ph.D., Professor Emeritus