C 60 in olive oil causes light-dependent toxicity and does not extend lifespan in mice

C is a potent antioxidant that has been reported to substantially extend the lifespan of rodents when formulated in olive oil (C -OO) or extra virgin olive oil (C60-EVOO). Despite there being no regulated form of C -OO, people have begun obtaining it from online sources and dosing it to themselves or their pets, presumably with the assumption of safety and efficacy. In this study, we obtain C -OO from a sample of online vendors, and find marked discrepancies in appearance, impurity profile, concentration, and activity relative to pristine C -OO formulated in-house. We additionally find that pristine C -OO causes no acute toxicity in a rodent model but does form toxic species that can cause significant morbidity and mortality in mice in under 2 weeks when exposed to light levels consistent with ambient light. Intraperitoneal injections of C -OO did not affect the lifespan of CB6F1 female mice. Finally, we conduct a lifespan and health span study in males and females C57BL/6 J mice comparing oral treatment with pristine C -EVOO and EVOO alone versus untreated controls. We failed to observe significant lifespan and health span benefits of C -EVOO or EVOO supplementation compared to untreated controls, both starting the treatment in adult or old age. Our results call into question the biological benefit of C -OO in aging.