A new study published in the Proceedings of the National Academies of the Sciences has revealed that females have a younger metabolic brain than males on average. The study looked at PET scan images of over 200 normal adults aged 20 to 82 years of age. A decline in brain metabolism is part of the normal aging process in humans, however, the rate of this decline varies from individual to individual due to several factors. It seems from this study that sex is one of these biggest factors. An algorithm was applied to the data to calculate the metabolic brain age of all the participants and compared that result with the individuals actual age. Overall, the typical female brain was more youthful by several years than that of their male counterparts, regardless of actual age. The reasons behind this observation is not yet clear so more studies on a larger scale would be needed to further understand this phenomenon. One suspected reason is that females show heightened brain glycolysis,...