Low Mitochondrial DNA Copy Number Linked to Higher Mortality in Older Adults

Mitochondrial DNA copy number (mtDNA-CN) in white blood cells has emerged as a promising biomarker of cellular aging. This study examined the relationship between leukocyte mtDNA-CN, inflammation, and mortality in older adults. Researchers found that lower mtDNA-CN was associated with significantly higher mortality risk, and this effect was amplified when combined with elevated inflammatory markers. The findings suggest that mitochondrial dysfunction and chronic inflammation—two hallmarks of aging—work synergistically to accelerate health decline. What makes this particularly valuable is that mtDNA-CN can be measured from a simple blood test, potentially offering clinicians a practical tool for identifying older adults at highest risk. The study adds to growing evidence that maintaining mitochondrial health may be key to healthy longevity. While we can't yet directly boost mtDNA-CN therapeutically, lifestyle interventions like exercise and caloric restriction that support mitochondrial function may indirectly help preserve this marker and the health outcomes it predicts.