The brain has a very high rate of energy consumption relative to its size, and requires a ready supply of ‘fuel’. Glucose is the major fuel for the brain, and the continuous delivery of glucose via the bloodstream is essential for the normal functioning of the central nervous system. The relationship between normal brain functioning and glucose has been well established for many years. However, it was not until relatively recently that systematic investigations into the cognitive effects of variations in blood glucose levels were begun. Over the past decade, it has been clearly demonstrated that changes in blood glucose levels can affect memory processes. We here present some of our studies that have investigated whether the administration of glucose (and its primary biochemical reagent—oxygen) can significantly facilitate memory processes in healthy, young individuals. The implications of our findings for the cognitive neuroscience of memory will also be considered.