Age-related decline in natural killer cell function stems from disrupted glycolysis and mitochondrial metabolism, according to new mechanistic research. Scientists identified specific metabolic pathways that become impaired in older NK cells, reducing their cytotoxic capacity against cancer cells and infected tissue. The metabolic dysfunction appears reversible through targeted interventions that restore cellular energy production. This represents a significant advance in understanding immunosenescence at the molecular level. Previous research established that NK cells lose killing power with age, but the underlying mechanisms remained unclear. This metabolic framework could inform therapeutic strategies for age-related immune decline, potentially benefiting cancer surveillance and infection resistance in older adults. The approach differs from conventional immunotherapy by targeting cellular metabolism rather than surface receptors or signaling cascades. However, translation to clinical interventions requires validation in human studies and development of specific metabolic modulators. The findings also raise questions about whether similar metabolic restoration could rejuvenate other immune cell types that decline with aging. If confirmed, metabolic reprogramming might become a cornerstone of immunological aging interventions.