Small increases in mitochondrial energy production led to significant improvements in health and longevity in mice. Mice genetically engineered to have an enhanced protein that promotes mitochondrial efficiency lived longer and had better metabolism, stronger muscles and healthier fat tissue. The cells of these mice produced more energy (ATP) compared to controls. At the same time, signs of oxidative stress associated with aging were reduced. The modified mice also showed lower levels of age-related inflammation. The authors of the study report that improving cellular energy performance can slow down the aging process.