An Evolutionary Approach
Chronic diseases such as heart disease, diabetes, and obesity have become alarmingly prevalent in industrialized nations.
What is striking, however, is that these high rates of chronic illness are now often considered normal, largely because they affect such a large portion of the population. Rates of these diseases were exceptionally low among human populations just a few generations ago.
Furthermore, in the wild, non-human species rarely experience chronic diseases unless they are exposed to human influence, such as captivity or a highly unnatural environment. This observation raises a critical question: Why are humans, alone among animals, now facing such an overwhelming burden of chronic illness?
Health and Longevity in Traditional Societies and Blue Zones
One of the strongest arguments against the inevitability of chronic diseases comes from studying populations with exceptionally low rates of these illnesses. "Blue Zones" are regions of the world where people live significantly longer and healthier lives. Examples include the inhabitants of Okinawa, Japan, and Sardinia, Italy. In these communities, diseases like diabetes and heart disease are rare, and people often live well into old age without significant disability.
Similarly, traditional, tribe-based societies such as the Hadza of Tanzania or the Tsimane of Bolivia, who still live lifestyles much closer to those of our ancestors, exhibit remarkably low rates of chronic disease. These populations do not have access to modern healthcare, yet they suffer far less from the conditions that plague industrialized societies. The stark difference in health outcomes strongly suggests that something about modern diet and lifestyle choices is contributing to the chronic disease epidemic.
Comparing Ancestral and Modern Diets and Lifestyles
The diet and lifestyle of ancestral humans were fundamentally different from those of modern humans. For hundreds of thousands of years, humans lived as hunter-gatherers, consuming a diverse diet of plants, fruits, nuts, seeds, fish, and game.
Their diet was nutrient-dense, rich in fiber, protein, and healthy fats. Physical activity was also built into their daily lives through the need to hunt, gather, and travel long distances. They were exposed to natural environments, experienced natural sleep patterns, and lived in small, tightly-knit communities.
In contrast, the modern human diet is dominated by processed foods high in refined sugars, unhealthy fats, and additives. Sedentary lifestyles, prolonged exposure to artificial light, and increasing isolation from community structures contribute to stress and mental health issues. This dramatic departure from our evolutionary past has led to a mismatch between our biology and the environment, a phenomenon that is often identified as the root cause of many chronic diseases.
Evolution as a Central Concept for Simplifying Health
Using evolution as a central organizing concept for understanding health provides a powerful framework. Evolution acts as the "trunk" of the tree, offering a foundation to which more specific, nuanced health information can be attached as branches. By considering how humans are biologically adapted to live, eat, and move, we can make informed decisions that align with our evolutionary history.
This approach simplifies the overwhelming flood of modern health information by offering clear guiding principles: consume foods that are unprocessed and nutrient-dense, prioritize physical activity, maintain social connections, and reduce exposure to artificial stressors.