Low doses of radiation can enhance insect lifespans.

This paper assesses the capacity of ionizing radiation to extend the lifespans of experimental insect models based on the peer-reviewed literature. Ionizing radiation biphasically affects the lifespans of adult males and females for a broad range of insect models with high doses reducing lifespan whereas lower doses can enhance lifespan, typically in the 20-60 % range. The average adult insect lifespan can be increased when ionizing radiation exposure is administered during early developmental stages or during the adult stage. The effective dose inducing the average adult insect lifespan enhancement may vary considerably depending upon which life stage is exposed. Recent findings have identified specific genes affecting anti-oxidant defenses, DNA repair, apoptosis and heat shock proteins as well as several cell signaling pathways that mediate the longevity enhancing hormetic response.