Evolution, Diet, and Disease: Analyzing Modern Health through Biological and Cultural Lenses

Biological estrangement

Our bodies evolved for a hunter-gatherer lifestyle—lots of physical activity and natural foods—but modern life is sedentary and full of processed, high-calorie foods. This mismatch causes many modern health problems.

Paleolithic diet

Lean meat, fish, fruits, vegetables, nuts, seeds, high fiber; little fat, salt, or sugar.

Modern diet

Processed foods, refined sugars, high salt, saturated fats.

Health lessons from hunter-gatherers

Stay active, eat unprocessed foods, consume more plants and lean protein, and avoid refined sugar, salt, and fat—reduces risk of heart disease, obesity, diabetes, and cancer.

Evolutionary medicine

Looks at the ultimate causes (why diseases exist, via evolution).

Biomedicine

Looks at the proximate causes (how diseases occur—pathogens, genetics, physiology).

Cultural influence on disease

Culture shapes what is considered 'normal' or 'illness.' Examples: depression, obesity, and menopause vary across societies.

Ontogeny

Early nutrition affects metabolism and obesity risk later.

Phylogeny

Humans evolved to store fat ('thrifty gene hypothesis').

Neurobehavioral

Brains evolved to crave high-calorie foods for survival.

Balanced polymorphism

One sickle cell gene protects against malaria (heterozygous advantage). Two genes cause sickle cell anemia (homozygous disadvantage). The trait persists because it's beneficial in malaria regions.

Antibiotic resistance

Overuse/misuse of antibiotics kills weak bacteria, leaving resistant ones to multiply. Fast bacterial evolution spreads resistance genes quickly.

Biocultural approach to pica

Combines biological (nutritional or detox reasons) and cultural (beliefs, customs, habits) explanations; recognizes that both environment and culture shape behavior.

Protection-detoxification hypothesis for pica

Eating clay or soil (geophagy) binds and neutralizes toxins, bacteria, and parasites. Studies show certain clays absorb harmful substances in the gut.

Diseases of Civilization

Chronic diseases (heart disease, diabetes, obesity) linked to modern lifestyle.

Epidemiologic Boundary

The point between one pattern of disease and the next (e.g., infectious → chronic).

High Energy/Satiety Foods

Foods dense in calories and fat that satisfy hunger but can cause obesity.

Proximate Causes

Immediate causes of disease (pathogens, physiology).

Ultimate Causes

Evolutionary 'why' causes (adaptations, trade-offs).

Character Fitness

How much do traits contribute to reproductive success?

The Hygiene Hypothesis

Lack of early microbe exposure → more allergies and autoimmune diseases.

Antagonistic Pleiotropy (ApoE4)

Genes are helpful early in life but harmful later (e.g., ApoE4 → Alzheimer's).

Amylophagy

Eating starch.

Geophagy

Eating earth or clay.

Pagophagy

Eating ice.

Protection-Detoxification Hypothesis

Pica neutralizes toxins and pathogens.

Pica in Animals

Animals eat non-foods for nutrients or toxin protection.

Pasteurization

Heating food/drink to kill pathogens.

Infant Mortality

Number of infant deaths per 1,000 live births.

Vector-borne diseases

Diseases spread by insects or animals (e.g., malaria, dengue).

Desertification

Land degradation that worsens health/agriculture.

Macroparasitism

Infection by large organisms like worms.

Epidemiologic Transition

Shift from infectious to chronic diseases.

Zoonoses

Diseases transmitted from animals to humans.

First Epidemiologic Transition

Rise of infectious diseases with agriculture.

Second Epidemiologic Transition

Shift to chronic diseases in industrial societies.

Third Epidemiologic Transition

Re-emergence of infectious diseases from globalization and resistance.

Stratification

Unequal access to resources causes health disparities.