Metabolic Agents that Enhance ATP can Improve Cognitive Functioning: A Review of the Evidence for Glucose, Oxygen, Pyruvate, Creatine, and L-Carnitine

Over the past four or five decades, there has been increasing interest in the neurochemical regulation of cognition. This field received considerable attention in the 1980s, with the identification of possible cognition enhancing agents or “smart drugs”. Even though many of the optimistic claims for some agents have proven premature, evidence suggests that several metabolic agents may prove to be effective in improving and preserving cognitive performance and may lead to better cognitive aging through the lifespan. Aging is characterized by a progressive deterioration in physiological functions and metabolic processes. There are a number of agents with the potential to improve metabolic activity. Research is now beginning to identify these various agents and delineate their potential usefulness for improving cognition in health and disease. This review provides a brief overview of the metabolic agents glucose, oxygen, pyruvate, creatine, and L-carnitine and their beneficial effects on cognitive function. These agents are directly responsible for generating ATP (adenosine triphosphate) the main cellular currency of energy. The brain is the most metabolically active organ in the body and as such is particularly vulnerable to disruption of energy resources. Therefore interventions that sustain adenosine triphosphate (ATP) levels may have importance for improving neuronal dysfunction and loss. Moreover, recently, it has been observed that environmental conditions and diet can affect transgenerational gene expression via epigenetic mechanisms. Metabolic agents might play a role in regulation of nutritional epigenetic effects. In summary, the reviewed metabolic agents represent a promising strategy for improving cognitive function and possibly slowing or preventing cognitive decline

The Influence of Fat Co-administration on the Glucose Memory Facilitation Effect.

Memory for a list of 20 words can be enhanced when learning is preceded by consumption of 25 g of glucose, compared with consumption of an equally sweet aspartame solution. The present study examined whether memory performance is also enhanced when glucose is administered in conjunction with another food constituent, in particular fat. Four groups of healthy young participants were tested under one of four conditions: (a) glucose 1 full-fat yoghurt; (b) glucose 1 fat-free yoghurt; (c) aspartame 1 full-fat yoghurt; (d) aspartame 1 fat-free yoghurt. The groups were compared on measures of blood glucose and cognitive performance. Participants receiving a glucose drink in conjunction with a fat-free yoghurt displayed higher blood glucose levels (BGL) and better performance on short- and long- delay recall of the word list compared with (a) individuals who consumed the glucose drink in conjunction with a full-fat yoghurt and (b) individuals who consumed the aspartame drink. The glycaemic data indicated that the presence of fat slows down glucose absorption. The findings suggest that only foods with a relatively fast glucose absorption rate are able to significantly enhance the encoding and long-term retention of novel memory materials in healthy young adults

Stress Reactivity and Cognitive Performance in a Simulated Firefighting Emergency

Background: During emergencies maladaptive behavior can reduce survival. This study compared the effects of a basic firefighter training course on 21 volunteers (with no firefighting experience) with age and gender-matched controls. Methods: Stress reactivity (salivary cortisol and anxiety) were monitored across the course: day 1 (classroom), day 2 (physical equipment training), and day 3 (simulated fire emergency). Cognitive performance (visual attention, declarative and working memory) considered important in surviving a fire emergency were measured immediately post-training or after a 20-min delay. Results: Prior to threat subjects showed an anticipatory cortisol increase but no corresponding increase in self-reported anxiety. On day 3 cortisol was higher in firefighters tested immediately after (10.37 nmol · L−1) and 20 min after training (7.20 nmol · L−1) compared to controls (3.13 nmol · L−1). Differences in cognitive performance were observed post-threat, with impairments in visual declarative memory in the firefighting subjects tested immediately, and working memory impairments observed in those tested after a 20-min delay. Conclusions: Cognitive impairments were found following a simulated emergency and could explain maladaptive responses observed during real fires. Moreover, the results suggest the type of cognitive impairments observed may be time dependent, with different cognitive difficulties becoming evident at different times following an emergency