Myths vs facts: FTO and Langlebigkeit

The FTO locus (e.g., rs9939609) is one of the most robustly replicated genetic markers for obesity and BMI. GWAS studies show a small but significant effect on body weight. However, it is often falsely claimed that FTO variants directly influence longevity. In reality, longevity is an extremely polygenic trait determined by hundreds of genes, lifestyle, environment, and epigenetics. The effect of individual FTO variants on life expectancy is indirect and minimal – if anything, through metabolic risk factors like obesity, which are associated with chronic diseases. Direct-to-consumer DNA tests tend to exaggerate such associations, often implying a direct 'longevity gene' effect. The evidence is clear: FTO is an obesity gene, not a longevity gene. Those looking to improve their lifespan should focus on diet, exercise, and lifestyle – not a single gene.