Original story from the University of Otago – Ōtākou Whakaihu Waka (Dunedin, New Zealand). Hormonal contraception and permanent surgical sterilization increase life expectancy, a study across 117 mammals suggests. Blocking reproduction increases lifespan in both males and females of many different species, a new international University of Otago – Ōtākou Whakaihu Waka-led (Dunedin, New Zealand) study has found. Using data from mammals housed in zoos and aquariums worldwide, the researchers found ongoing hormonal contraception and permanent surgical sterilization were associated with increased life expectancy. Lead author Mike Garratt, of Otago’s Faculty of Biomedical Sciences, notes that while the relative increase in lifespan was similar across sexes, the cause may be different in males and females. “In males, only castration extends lifespan – not vasectomy – which indicates that the effect comes from removing sex hormones. These hormones may interact with pathways that regulate the biology of aging, particularly during early-life development, since early-life castration has the strongest effects on lifespan. Health in later life is also increased by castration in laboratory rodents. “In females, lifespan increases after several different forms of sterilization, suggesting that benefits arise from reducing the substantial energetic and physiological costs of pregnancy, lactation and caring for offspring, rather than from a single hormonal mechanism,” he adds. The study, published in prestigious international journal Nature, included analysis of 117 different species, along with a meta-analysis of other vertebrate sterilization studies. The researchers found life expectancy increased by 10 to 20%, depending on the timing of treatment and…
