Lay opinion vs evidence: DNA Test Basis

Lay opinions often overestimate the predictive power of consumer DNA tests. The evidence base is mixed: some markers like ALDH2 (alcohol flush) have strong human evidence, while others like the longevity panel (IL-6, CRP, SOD2) show only small effect sizes and are not clinically predictive. Many tests (e.g., food intolerance, endurance genetics) rely on weak or marketing-driven evidence. The scientific reality is that most SNPs have tiny effect sizes, and lifestyle factors dominate health outcomes. Consumer tests can provide interesting insights but should not be used for medical decisions. Evidence ranges from mechanistic to human-observational, with few robust clinical validations. A critical, evidence-aware perspective is essential.