Refining human brain metabolism trajectories: Convergence, uncertainties and the value of arteriovenous data

Structural brain aging trajectories are increasingly well characterized in very large datasets, but metabolic trajectories remain less clear. It has been proposed that CMRglc may fall faster than CMRO₂ with age, though this view has been questioned. In this context, Duffy et al. now provide a rare contribution by assembling brain arteriovenous data from >200 adults aged 19-45 years. Their results offer an opportunity to refine our understanding of brain metabolism trajectories and highlight the challenges in studying this question.