The Role of Animal-Based Foods in Human Evolution: Why Our Dietary History Matters
I recently came across an Instagram post where some vegan influencers argued that dairy and other animal-based foods have no place in the human food chain, even labeling the dairy industry as "propaganda." As a vegan myself, I believe it’s essential to base such claims on science and historical context. In my opinion, dairy is a stepping stone towards veganism because it is less cruel and more efficient than hunting in the wild. However, it's important to acknowledge the historical significance of animal-based foods in our survival and evolution. Here’s why understanding our species’ dietary history matters in today’s conversation about nutrition.
Humans as Omnivores: Archaeological and Evolutionary Evidence
Archaeological evidence shows that early humans were omnivores, relying on both plants and animals for food. Stone tools, animal bones, and cave paintings suggest our ancestors hunted and consumed animals for survival. These early humans were hunter-gatherers, and animal-based foods provided essential nutrients they couldn’t get from plant sources alone, supporting their growth, brain development, and physical health.
Nutritional Contributions of Animal-Based Foods to Human Development
Animal-based foods offered a reliable source of nutrients that were essential for our ancestors’ survival:
- Dense and Complete Proteins: Animal proteins contain all essential amino acids that our bodies need. They are dense sources of protein because they lack cellulose and are often lean, meaning more protein per calorie without extra carbohydrates.
- Vitamin B12: Vitamin B12 is vital for nerve function, red blood cell production, and DNA synthesis. It is made by bacteria and accumulates in animal tissues. Plants don’t produce or store B12, making animal foods the primary source for early humans.
- Vitamin D: Vitamin D is essential for bone strength, immune function, and calcium absorption, but plants don’t produce it. While humans can make vitamin D through sunlight, factors like clothing and limited sun exposure often reduce this. Animal foods helped meet this need, especially in colder regions.
- Omega-3 Fatty Acids (DHA & EPA): DHA and EPA, crucial for brain function, heart health, and reducing inflammation, are found mainly in fish and other animal foods. While plants provide ALA (another type of omega-3), humans can’t convert ALA into DHA and EPA efficiently.
- Overall Health: Together, animal proteins, vitamin B12, vitamin D and omega-3 fatty acids played a major role in supporting muscle growth, heart health, nerve function, and immunity, allowing early humans to thrive in challenging environments.
The Historical Context of Dairy Consumption
Dairy products emerged as a result of a symbiotic relationship between early agricultural communities and cattle. Humans began to domesticate animals for their milk, leading to a mutually beneficial arrangement: cattle provided nourishment, while humans offered protection and care. This relationship allowed early agricultural societies to replace some of the reliance on meat with nutrient-rich dairy, diversifying their diets.
However, this relationship has evolved over time. In modern society, it has shifted from a symbiotic connection to an exploitative one, where cattle are often artificially impregnated and trapped in prison-like states to maximize milk production, driven by consumerism and capitalism.
Challenges of a Natural Plant-Based Diet for Prehistoric Nutritional Needs
While modern humans can meet their dietary requirements with agriculture and food processing, early humans didn’t have access to these tools and faced unique challenges when relying solely on wild plants:
- Missing Nutrients : Early humans needed key nutrients that plant sources often lack, such as vitamin B12, vitamin D, omega-3 fatty acids, and certain minerals.
- Low Protein Density in Wild Plants : Wild plants have lower protein content and smaller amounts of essential amino acids like lysine and methionine. Animal sources offered more concentrated protein, supporting muscle growth and energy.
- Foraging Limitations : Gathering enough wild plant-based foods to meet daily protein and calorie needs was challenging and often impractical. Animal-based foods provided a more efficient way to meet these needs.
Dietary Pressure and Evolutionary Adaptation
Throughout evolution, the availability of certain nutrients led to dietary pressure, a mechanism driving biological adaptation based on nutrient availability:
- Vitamin C : Primates, including humans, originally had the ability to produce vitamin C internally. However, our fruit-rich diets provided a constant external source of vitamin C, eventually leading to the loss of this ability as it was no longer essential. Interestingly, the genetic sequence for producing vitamin C still exists in our genome, though it remains inactive due to this evolutionary adaptation.
- Vitamin B12 : This essential nutrient is synthesized by bacteria found in soil and water. In nature, animals consume these bacteria directly or indirectly, allowing B12 to accumulate in their tissues, which humans then access through animal-based foods. Plants, however, do not accumulate B12. Vitamin B12 is a complex molecule that evolved in bacteria and is present abundantly in nature; hence, there was no evolutionary pressure for animals or plants to reinvent its production.
- ALA to DHA/EPA Conversion : Humans are not efficient at converting plant-based ALA (alpha-linolenic acid) into DHA and EPA, the long-chain omega-3 fatty acids critical for brain health and cardiovascular function. Our ancestors had plenty of DHA and EPA from animal sources in their diets, so we didn't evolve effective conversion mechanisms from ALA, as the dietary sources were sufficient.
- Vitamin D : The ability to produce vitamin D through sunlight exposure is influenced by clothing and modern lifestyles, which reduce skin exposure to sunlight. With the abundance of Vitamin D in animal food sources, this reliance diminished, making dietary sources of vitamin D increasingly important.
Modern Solutions Enabled by Agriculture and Technology
While our ancestors had to rely on naturally available sources, modern agriculture and food technology allow us to meet dietary needs without animal-based foods. However, it’s important to recognize these solutions as recent innovations:
- Agricultural Advances : Today, humans can cultivate high-protein plants like soy and process foods to concentrate nutrients, which helps meet dietary requirements. Early humans had limited access to these innovations, making animal sources essential.
- Nutritional Supplements : Modern supplements provide essential nutrients like B12, DHA & EPA, and vitamin D, which previously came primarily from animal sources. These advancements reflect our modern ability to meet our nutritional needs without relying on animal products.
Conclusion: Evolutionary Adaptations Inform Modern Nutrition
Animal-based foods played a fundamental role in our evolution, supporting essential functions like muscle growth, brain development, and immune health. While modern technology and dietary science offer plant-based solutions, understanding our evolutionary dietary history provides important context for today’s conversations on nutrition. Balancing this knowledge with modern choices can support a well-rounded, informed approach to health and diet.
