In genetically heterogeneous mice, 8% glycine supplementation does not significantly alter the incidence of 40 age-related pathologies, including hematopoietic tumors, degenerative lesions, or metastatic cancers, while its effects are specific to lifespan extension and pulmonary adenocarcinoma reduction.

Extra glycine in the blood enters lung cells called macrophages and opens special channels that let chloride ions flow in. This makes the macrophages less active and stops them from sending out inflammatory signals. With less inflammation in the lungs, tumors cannot grow as easily, so lung cancer becomes less common. This change does not affect other organs or diseases because the effect is limited to tissues where glycine receptors are present and active.