This is the skull of a specimen of Homo sapiens recovered from the Fertile Crescent, specifically Qafzeh, Israel, and dated to around 100,000 years ago (photographed through glass, on display at London’s Natural History Museum). We don’t know the age of the specimen at time of death, but it is clearly adult.
Note the full mouth of teeth, intact and apparently without decay. This is typical of specimens recovered prior to the incorporation of grains into the human diet: perfect teeth without decay, without abscess, without tooth loss, and without tooth crowding that we see so often today. Substantial tooth loss in primitive life was potentially life threatening, as eating the coarse foods of the age required effective mastication.
This is another photo from the same collection, this one a Neandertal from Kebara, Israel, dated to 60,000 years ago (approximately 30,000 years prior to their extinction). Note once again the full mouth of teeth without apparent decay or crowding. Although we are not descended from Neandertals, Homo sapiens are extremely close relatives, genetically close enough to allow crossbreeding. As with Homo sapiens specimens, tooth decay in Neandertal specimens are uncommon.
What makes this so fascinating is that neither Homo sapiens nor Neandertals had toothbrushes, toothpaste, fluoridated water, dental floss, dentists, or orthodontists, yet less than 1% of teeth recovered show evidence of decay. That all changed with the incorporation of grains–einkorn and emmer wheat in the Fertile Crescent, maize and teosinte in the Americas, sorghum and millet in sub-Saharan Africa: explosive tooth decay appeared, typically affecting 16-49% of all teeth recovered (varying depending on location and age). The Egyptians, among the earliest of civlizations of Homo sapiens, famous for their wheat, barley, and corn consuming ways, were the first to have dentists, some of whom developed techniques to drill into the mouth to remove cavities.
There’s more to health than dental health. But it is one powerful line of evidence suggesting that grains are not, nor never were, appropriate for human consumption. When we do consume them, we pay a substantial health price in the teeth and elsewhere. The evidence is pretty bad for grains in general, now exaggerated by the manipulations of geneticists to create modern high-yield, semi-dwarf wheat.
Wheat and grains are maladaptive. The seeds of grasses, i.e., all grains consumed by unwitting humans, are the food of the desperate or the ignorant.