For the vast majority of mankind’s presence on this planet, he rarely if ever consumed cereal grains. With the exception of the last 10,000 years following the agricultural ‘revolution’, humans have existed as non-cereal-eating hunter-gatherers since the emergence of Homo erectus 1.7 million years ago.
It is apparent that there is little or no evolutionary precedent in our species for grass seed consumption. Consequently, we have had little time (less than 500 generations) since the inception of the agricultural revolution 10,000 years ago to adapt to a food type which now represents humanity’s major source of both calories and protein. The sum of evidence indicates that the human genetic constitution has changed little in the past 40,000 years. The foods which were commonly available to pre-agricultural man were the foods which shaped modern man’s genetic nutritional requirements.
Generally, in most parts of the world, whenever cereal-based diets were first adopted as a staple food replacing the primarily animal-based diets of hunter-gatherers, there was a characteristic reduction in stature, an increase in infant mortality, a reduction in lifespan, an increased incidence of infectious diseases, an increase in iron deficiency anemia, an increased incidence of osteomalacia, porotic hyperostosis and other bone mineral disorders and an increase in the number of dental caries and enamel defects.
Consumption of high levels of whole grain cereal products impairs bone metabolism not only by limiting calcium intake, but by indirectly altering vitamin D metabolism. In animal studies it has been long recognized that excessive consumption of cereal grains can induce vitamin D deficiencies in a wide variety of animals including primates.
Consistent with populations from the fossil record showing a characteristic reduction in stature with the adoption of cereal-based agriculture, is the observation that present-day populations depending upon cereal grains for the bulk of their energy and protein also tend to be of short stature. Further, vegan and vegetarian children often fail to grow as well as their omnivorous cohorts despite apparently adequate intakes of amino acids and nitrogen.
Because primates evolved in the tropical forest, all of their potential plant food was derived from dicotyledonous species; therefore, the primate gut was initially adapted to both the nutritive and defensive components of dicotyledons rather than the nutritive and defense components of monocotyledonous cereal grains.
Consumption of monocotyledonous plant foods, particularly cereal grains, is a notable departure from the traditional plant foods consumed by the majority of primates. Consequently, humans, like all other primates, have had little evolutionary experience in developing resistance to secondary and anti-nutritional compounds which normally occur in cereal grains.
Lectins are proteins that are widespread in the plant kingdom with the unique property of binding to carbohydrate-containing molecules, particularly toward the sugar component. They were originally identified by their ability to agglutinate (clump) erythrocytes which occurs because of the interaction of multiple binding sites on the lectin molecule with specific glycoconjugate receptors on the surface of the erythrocyte cell membranes. Because of this binding property, lectins can interact with a variety of other cells in the body and are recognized as the major anti-nutrient of food.
Of the eight commonly consumed cereal grains, lectin activity has been demonstrated in wheat, rye, barley, oats, corn, and rice but not in sorghum or millet. The biological activity of lectins found in cereal grains are similar because they are closely related to one another both structurally and immunologically. The best studied of the cereal grain lectins is wheat germ agglutinin (WGA), and the in vitro biological effects of WGA upon tissues and organs are astonishingly widespread. In his comprehensive review, Freed has shown that WGA can bind (in vitro) the following tissues and organs: alimentary tract (mouth, stomach, intestines), pancreas, musculoskeletal system, kidney, skin, nervous and myelin tissues, reproductive organs, and platelets and plasma proteins.
Most food proteins entering the small intestine are fully degraded into their amino acid components and therefore do not pass intact into systemic circulation. However, it is increasingly being recognized that small quantities of dietary protein which escape digestive proteolytic breakdown can be systemically absorbed and presented by macrophages to competent lymphocytes of the immune system. Under normal circumstances, when the luminal concentrations of intact dietary proteins is low, absorbed proteins generally elicit a minimal allergic response because of the limiting influence of T-suppressor cells.
Because of their resistance to digestive, proteolytic breakdown, the luminal concentrations of lectins can be quite high, consequently their transport through the gut wall can exceed that of other dietary antigens by several orders of magnitude. Additionally, WGA and other lectins may facilitate the passage of undegraded dietary antigens into the systemic circulation by their ability to increase the permeability of the intestine. Consequently, dietary lectins represent powerful oral immunogens capable of eliciting specific and high antibody responses.
[Fathead comments: In other words, lectins can lead to leaky-gut syndrome. They poke holes in your intestines, seep into your bloodstream and are carried throughout your body, which then must produce antibodies to attack them. If that were the end of the story, it would be bad enough. But that’s not the end of the story. The amino-acid profile of lectins is similar to the amino-acid profile of many of your own tissues. The result of what Cordain calls “molecular mimicry” isn’t pretty.]
Autoimmune diseases occur when the body loses the ability to discriminate self proteins from nonself proteins. This loss of tolerance ultimately results in destruction of self tissues by the immune system.
So why are we told, over and over, that humans need grains to survive and reach optimal health? If for 99.6% of our existence as species we thrived without them, why suddenly they became the core of our health and well being?
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