Yeast longevity promoted by reversing aging-associated decline in heavy isotope content

Abstract

Dysregulation of metabolism develops with organismal aging. Both genetic and environmental manipulations promote longevity by effectively diverting various metabolic processes against aging. How these processes converge on the metabolome is not clear. Here we report that the heavy isotopic forms of common elements, a universal feature of metabolites, decline in yeast cells undergoing chronological aging. Supplementation of deuterium, a heavy hydrogen isotope, through heavy water (D2O) uptake extends yeast chronological lifespan (CLS) by up to 85% with minimal effects on growth. The CLS extension by D2O bypasses several known genetic regulators, but is abrogated by calorie restriction and mitochondrial deficiency. Heavy water substantially suppresses endogenous generation of reactive oxygen species (ROS) and slows the pace of metabolic consumption and disposal. Protection from aging by heavy isotopes might result from kinetic modulation of biochemical reactions. Altogether, our findings reveal a novel perspective of aging and new means for promoting longevity. The lifespan of yeast cells can be extended by supplying them with heavy isotopes of common elements, according to US researchers. Heavy isotopes such as deuterium–a type of hydrogen containing a neutron–exist in small quantities in natural environments, but their effects on living organisms are unclear. Michael Snyder and Xiyan Li at Stanford University showed for the first time that amino acids in yeast cells tend to contain lower levels of heavy isotopes as the cells age. They then incubated yeast cells with increased doses of ‘heavy water’ (which contains deuterium instead of hydrogen) and found that, remarkably, the yeast’s lifespan was extended by up to 85%. The researchers suggest that heavy isotopes affect biochemical reactions by strengthening molecular bonds, and suppress reactive oxygen species, thereby slowing the metabolism and prolonging life.