A new review traces humanity's complex 3-million-year relationship with red meat — from a survival food to a driver of chronic disease and environmental crisis.
A new interdisciplinary review published in The Quarterly Review of Biology argues that red meat, once an essential component of human evolution, has become a significant threat to human health and planetary sustainability. Juston Jaco, Kalyan Banda, Ajit Varki, and Pascal Gagneux, synthesize roughly three million years of hominin dietary history alongside modern epidemiological and molecular data to posit that the food source that likely shaped our species is now contributing to its undoing.
In " Red Meat in Human Evolution, Health, and Disease: From a Blessing to a Curse? " the authors trace the origins of meat consumption to before the emergence of the genus Homo, with archaeological evidence suggesting that early hominins incorporated animal-derived foods into an otherwise predominantly plant-based diet. The review challenges the narrative that lean muscle meat was primarily sought after. Fatty tissues, bone marrow, organs, and brain matter were likely more highly valued for their caloric density and essential lipids, particularly for fueling the developing infant brain. "The cultural prominence of red meat in modern Euro-American diets, typically centered on steaks and roasts, reflects ideals and biases that influence assumptions about early hominin diets," the authors write.
The review also complicates longstanding theories about meat's role in driving human brain expansion. The authors note that protein alone is neither energy-dense nor an optimal fuel for the brain, suggesting that a broad and flexible dietary strategy, incorporating diverse plant and animal foods, best explains human evolutionary success.
The transition to agriculture roughly 10,000 to 12,000 years ago marked a turning point. While food became more reliably available, dietary diversity shrank. Iron deficiency, rare among hunter-gatherers, became more prevalent as cereal-heavy diets limited the absorption of dietary iron.
Today, the global meat industry is valued at $1.3 trillion and is projected to grow further, particularly in low- and middle-income countries, and the authors document the health consequences of this modern appetite. Large-scale epidemiological studies consistently link red and processed meat consumption to elevated risks of cardiovascular disease, type 2 diabetes, colorectal cancer, and all-cause mortality. The International Agency for Research on Cancer classifies processed meat as a Group 1 carcinogen and unprocessed red meat as probably carcinogenic.
The paper also covers the role of a uniquely human molecular mechanism the authors refer to as "xenosialitis," a diet-mediated inflammatory process. Humans lost the ability to produce a sugar molecule called N-glycolylneuraminic acid (Neu5Gc) approximately two million years ago, yet this molecule is abundant in commonly eaten red meats. When consumed, Neu5Gc is incorporated into human tissues, where it interacts with antibodies the immune system produces against it, generating chronic low-grade inflammation that may drive atherosclerosis, colorectal cancer progression, and possibly cognitive decline. Meanwhile, industrial livestock production also generates roughly 15 percent of global greenhouse gas emissions, drives deforestation and contributes to widespread water contamination and antibiotic resistance.
The paper is not a mandate to give up red meat. Instead, it situates modern consumption patterns within a broader historical and biological framework, arguing that the same dietary flexibility that allowed our ancestors to thrive has, in its modern, industrialized form, become a source of chronic disease and ecological damage. "The nature, scale, and context of red meat consumption today differ drastically from those of our evolutionary past," the authors conclude.
The premier review journal in biology, The Quarterly Review of Biology has presented insightful historical, philosophical, and technical treatments of important biological topics since 1926. The QRB publishes outstanding review articles of generous length that are guided by an expansive, inclusive, and often humanistic understanding of biology.
