Dairy is one of the most controversial foods in modern nutrition. In this evidence-based deep dive, we examine whether humans are actually meant to consume cow’s milk, how dairy has been used throughout human history, what lactose intolerance really means, and why raw and traditionally produced dairy behaves very differently than modern processed milk.

Modern nutrition advice changes every decade — but human biology hasn’t. Across continents, climates, and thousands of years, the world’s healthiest cultures shared the same foundational foods. In this article, we explore the foods all thriving cultures had in common, why they worked so well with human physiology, and how modern diets drifted away from these principles — especially with the rise of ultra-processed foods and seed oils.

Blue Zones are often used as proof that humans thrive on a plant-based diet — but the real story is far more nuanced. When you look at anthropology, traditional food prep, and the actual diets of long-lived cultures, you’ll find meat, dairy, and properly prepared plants all play a role. Here’s what the Blue Zones really ate — and what we should actually learn from them.