Why Weston A. Price’s Theory on Jaw Development Missed the Mark, But His Message Was Correct

Weston A. Price's research on human diets and health still stands as one of the most influential works in the realm of nutrition. Traveling the world in the 1930s, he studied the dental health and physical development of populations isolated from modern civilization. These groups consistently exhibited excellent dental health, robust physical development, and no signs of chronic diseases plaguing industrialized societies. Price concluded that the key to their health lay in their traditional diets, rich in animal-based foods, which provided fat-soluble vitamins A, D, and what he called "Activator X" (now recognized as vitamin K2). However, while these nutrients are indeed crucial for health, we now know that Price's explanation of jaw development and straight teeth was only partially correct.

Price’s Universal Diet Findings

Price was correct in asserting that every traditional diet, regardless of location, contained animal-based foods, whether dairy, seafood, or organ meats. These foods provided essential nutrients, including the fat-soluble vitamins A, D, and K2, necessary for healthy bones, teeth, and overall physical development. These vitamins are critical for proper calcium utilization, immune function, and maintaining healthy bones and teeth.

Price’s Error

What Price failed to recognize is that while vitamins A, D, and K2 are essential for bone health, scant evidence exists that they ensure proper jaw development. Jaw size and alignment are heavily influenced by mechanical forces—a theory first made popular by my professor of anatomy at Columbia University, Dr. Melvin Moss. What he called the functional matrix theory. Specifically, the forces exerted by chewing stimulate bone growth in our jaws. In the populations Price studied, the need to chew harder, unprocessed foods from a young age played a critical role in the development of wide dental arches and strong, well-aligned teeth. Price had no way of knowing this fact in his day.

In contrast, modern diets are dominated by soft, ultra-processed foods that require minimal chewing. As a result, the muscles involved in chewing are not adequately exercised, and the bones experience less force, which is the stimulus for growth, leading to underdeveloped jaws and misaligned teeth. The modern prevalence of braces and wisdom teeth extractions is a direct result of this shift from tough, whole foods to soft, processed foods. Price believed that the modern diets he studied, which contained ten times less fat-soluble vitamins, caused smaller jaws. He never made the connection that modern foods were also softer, which is a greater cause of small jaws.

The Modern Diet: A Recipe for Chronic Disease

Every traditional population that Price studied had a nearby group with the same heritage that had been introduced to the “displacing foods of modern commerce.” In each instance, the modern populations had crooked teeth and inferior health. Today, in the modern world, chronic diseases like obesity, diabetes, heart disease, and dental issues have become the norm. Processed foods, which are soft, energy-dense, and nutrient-poor, dominate the Western diet. Refined carbohydrates, industrial seed oils, and sugar-laden products have replaced the tough, fibrous foods and nutrient-rich animal products that were once central to the human diet.

Processed foods are easy to eat and require little chewing, leading to underdeveloped jaws, misaligned teeth, and widespread dental decay. They also contribute to systemic inflammation, insulin resistance, and nutrient deficiencies, fueling the rise of chronic diseases. Refined carbohydrates spike blood sugar levels, while seed oils promote inflammation and diminish our ability to produce energy—both key drivers of modern metabolic disorders.

This shift in diet has profound effects not only on dental health but on overall physical health. The traditional diets that Price documented contained none of the "displacing foods of modern commerce" like refined sugars, white flour, or vegetable oils. Instead, they relied on nutrient-dense whole foods, particularly those of animal origin, which provided the essential fat-soluble vitamins and proteins necessary for good health.

The Role of Meat in Jaw Development

One of the most striking examples of the relationship between diet and jaw development comes from the study of Neanderthals and Paleolithic modern humans. Isotopic evidence shows that these populations were essentially carnivores, consuming diets rich in animal-based foods. Despite this, their dental health was excellent—there were no signs of tooth decay, misaligned teeth, or underdeveloped jaws.

What explains this? Meat, particularly from large animals, requires significant chewing. The physical act of chewing tough, fibrous meat ensured that their jaws developed fully. Unlike modern humans, who rely on soft, processed foods, these ancient populations had well-developed jaws with ample room for all their teeth, including wisdom teeth.

This evidence suggests that meat itself—tough, fibrous, and nutrient-dense—was sufficient to ensure proper jaw development in early humans. Vitamins A, D, and K2 were indeed important for overall health, but the mechanical act of chewing meat played an equally critical role in developing the wide dental arches and strong teeth seen in ancient populations.

In Price’s conclusions, vitamins A, D, and K2 may have been proxies for diets that naturally included tougher, more fibrous foods, especially meat. Traditional meat-based diets provided not only the essential nutrients for health but also the physical challenge of chewing that ensured proper jaw development.

Conclusion: The Real Human Diet

Weston A. Price was correct in asserting that a diet free from modern processed foods is the key to health. His emphasis on the importance of animal-based foods and their fat-soluble vitamins was well-founded, but it did not tell the whole story. Modern research shows that while vitamins A, D, and K2 are vital for bone health, they are also proxies for a diet of animal-based foods that require significant chewing.

The human diet, at its core, includes tough, fibrous foods—particularly animal-based foods with their inherent fats. This combination not only provides the nutrients we need for overall health but also promotes proper jaw development, preventing dental issues that are so common in modern populations.

The lesson from both traditional societies and our Paleolithic ancestors is clear: a whole foods diet rich in animal products with their inherent fats and fat-soluble vitamins, combined with the physical act of chewing tougher foods, is the foundation of human health. By returning to this diet, free from processed foods and refined carbohydrates, we can avoid the chronic diseases and dental problems that plague modern society.