Common mistakes around DNA Test Basis

A common mistake with DNA tests is overestimating their predictive power. Many consumers believe that a genetic test can provide precise personalized diet or health recommendations. However, the scientific reality is that most tested variants (e.g., FTO rs9939609 for obesity, MTHFR C677T for folate metabolism) have very small effect sizes (odds ratio 1.2–1.3) and explain only a tiny fraction of individual risk. Moreover, many associations are population-specific – polygenic risk scores developed in Europeans often do not transfer to other ethnicities. Another mistake is confusing association with causation: just because a gene is linked to a trait does not mean that changing your diet will specifically alter that trait. Claims like 'your DNA test shows you need a low-carb diet' are not supported by randomized trials. Also, interpreting 'risk variants' as destiny is wrong – most genes interact with environment and lifestyle. Consumers should understand that DNA tests can at best provide rough hints, but not clinically validated action plans. The evidence for personalized diets based on DNA is currently weak to moderate.