Why We Get Cancer in the First Place

The Collision Theory of Cancer: When Ancient Design Meets Modern Living

Cancer may fundamentally represent the collision between our ancient biology—whether shaped through evolutionary processes or intelligent design—and the radically different environment we’ve created in just the past few generations. This profound mismatch between our biological heritage and contemporary lifestyle provides a compelling framework for understanding the epidemic of malignancies in industrialized societies and explains why cancer has become a leading cause of mortality despite being relatively rare throughout most of human history.

Biological Design vs. Modern Carcinogenic Environments

The human body exhibits remarkably sophisticated and intricate design, with cellular defense systems, DNA repair mechanisms, and metabolic pathways finely tuned to function in environments fundamentally different from today’s world. Whether these systems emerged gradually through natural selection or were purposefully designed, they developed in contexts characterized by natural foods, diverse microbial exposures, physical activity integrated into daily life, and the absence of synthetic chemicals and radiation sources.

Yet in just 150 years—a mere instant in biological time—we’ve created environments featuring thousands of novel chemical compounds, processed foods with unrecognizable molecular structures, unprecedented radiation exposures, and sedentary lifestyles that dramatically alter our cellular environments. Our DNA repair and cancer surveillance systems simply weren’t prepared for these new challenges, creating mismatches that manifest as increasing cancer incidence across virtually all industrialized populations.

Cellular Defense Systems Overwhelmed

Our cells possess sophisticated anti-cancer defense mechanisms initially suited for pre-industrial conditions. Tumor suppressor genes, DNA repair enzymes, apoptotic pathways, and immune surveillance systems represent a multi-layered defense system that effectively prevented cancer throughout most of human history. The elegance and complexity of these systems point to either remarkable adaptive development or intentional design for our protection.

However, these systems now face unprecedented challenges they weren’t prepared to handle. Constant insulin and IGF-1 signaling from high-glycemic diets promote cellular proliferation pathways that, when continuously activated, create favorable conditions for cancer development. Chronic inflammation from gut microbial disruption creates tissue environments that promote mutation and impair immune surveillance. DNA repair mechanisms become overwhelmed by persistent exposure to novel environmental mutagens. These combined pressures overwhelm our sophisticated cancer prevention systems, enabling malignancies to develop with increasing frequency.

The Gut Microbiome: A Critical Mediator in Cancer Development

The gut microbiome represents a critical interface between our biological heritage and modern carcinogenic environments. This complex ecosystem of microorganisms appears exquisitely designed to work in harmony with human cells, suggesting either co-evolution or intentional complementary design. When disrupted by industrial diets, the microbiome shifts from cancer-protective to cancer-promoting functions.

Beneficial bacteria that metabolize dietary fiber into protective short-chain fatty acids like butyrate—which regulate cell proliferation and promote apoptosis in damaged cells—diminish dramatically. Meanwhile, bacteria that produce genotoxic and pro-inflammatory compounds flourish. This dysbiosis directly impacts cancer development through multiple mechanisms, creating higher levels of secondary bile acids known to promote colorectal carcinogenesis, generating nitrosamines and other carcinogenic compounds, impairing intestinal barrier function, and modifying estrogen metabolism.

Studies examining populations transitioning from traditional to Western lifestyles show rapid increases in colorectal, breast, prostate, and other cancers—often within a single generation—corresponding precisely with measurable changes in their gut microbial composition.

Beyond Diet: Modern Lifestyle Factors in Carcinogenesis

While diet represents a primary collision point, other aspects of modern life also create pro-carcinogenic mismatches. The human body appears designed for particular rest-activity cycles aligned with natural light, yet modern living disrupts these patterns. Disrupted sleep and circadian rhythms impair specialized DNA repair processes that preferentially occur during specific sleep phases. Light exposure at night suppresses melatonin, which has important anti-cancer properties.

Physical inactivity runs counter to our apparent design for regular movement and exertion. Our bodies function optimally with regular physical activity that stimulates immune surveillance and metabolic signaling, yet modern sedentary living eliminates these cancer-protective effects.

Environmental pollutants interact with our biological systems in ways never anticipated in our design or evolutionary history. Many contemporary synthetic chemicals mimic hormones, disrupt cellular signaling, damage DNA, or impair detoxification pathways. Our detoxification systems were designed to handle natural compounds, not thousands of novel synthetic molecules now present in our environment.

Chronic psychosocial stress creates hormonal environments that suppress immune function, accelerate cellular aging, and promote inflammation—all factors that enable cancer development. Whether through evolution or design, our stress response was calibrated to handle acute physical threats followed by recovery periods, not the persistent psychological stressors characteristic of modern society.

Evidence Supporting the Biological Mismatch View of Cancer

Multiple lines of evidence support this biological mismatch view of cancer. Migration studies show dramatic increases in cancer rates when people move from low to high-incidence regions, often reaching the destination population’s cancer rates within one generation—far too quickly for genetic adaptation, but consistent with environmental and microbial changes.

Historical analyses reveal that many common cancers today were exceedingly rare in pre-industrial populations, with physicians of previous centuries documenting cancer as an unusual finding. Archaeological studies of ancient human remains find minimal evidence of malignancies compared to modern populations, even when accounting for shorter lifespans.

Perhaps most compelling are studies of contemporary populations maintaining traditional lifestyles, who exhibit remarkably low cancer rates despite limited access to modern medical care. The sharp increase in cancer incidence following the adoption of Western diets and lifestyles in these populations provides powerful evidence for the mismatch hypothesis.

Implications for Cancer Prevention and Treatment

Viewing cancer as a biological mismatch suggests we should design interventions that realign with our inherent biological nature rather than solely targeting specific molecular pathways. This approach recognizes that multiple small mismatches collectively create carcinogenic conditions, requiring comprehensive lifestyle approaches for effective prevention.

Dietary interventions that restore biological alignment—emphasizing diverse plant foods, appropriate fiber intake, moderate protein consumption, and traditional fermentation—may provide more powerful cancer prevention than isolated supplements or pharmaceutical approaches. Physical activity patterns that mirror our apparent design for movement, rather than segmented “exercise,” appear to activate inherent pathways that suppress cancer development.

Restoring proper circadian rhythms, reducing exposure to synthetic chemicals, and fostering connection and belonging may all represent critical but underappreciated aspects of cancer prevention that make sense through the biological mismatch lens.

For those already diagnosed with cancer, incorporating biologically aligned approaches alongside conventional treatments may help address the underlying mismatches that enabled cancer development initially. This integrative perspective doesn’t diminish the value of modern oncology but complements it by addressing fundamental biological contexts.

The most effective approach may be neither purely traditional nor exclusively high-tech, but rather a thoughtful integration that respects our biological heritage while leveraging modern scientific understanding to create environments where cancer has difficulty emerging and progressing.

References:

Why We Get Cancer in the First Place

Dr. Daniel Thomas, DO, MS