Mental energy: plausible neurological mechanisms and emerging research on the effects of natural dietary compounds

ABSTRACT

Objective: Lack of mental energy is one of the leading reasons adults turn to dietary supplements, with three out of ten supplement users hoping to improve their energy level; even more consume caffeine-containing products for the same reason. Despite this interest from consumers, there is no consensus scientific definition of mental energy or sole validated instrument for measuring it. We performed this review to summarize main findings from research regarding the influence of natural dietary compounds on three aspects of mental energy: cognition (vigilance), motivation (to do mental work), and mood (feelings of energy and/or absence of feelings of fatigue).

Methods: A narrative review of key papers.

Results: In addition to caffeine, a number of other compounds, including the polyphenols, which are found in all plant-derived products, and the phytochemicals in culinary herbs and herbal products such as Panax ginseng and Ginkgo biloba, have been shown in animal models to modulate neurotransmitter activity potentially relevant to mental energy. Inadequate intake of B vitamins could also potentially have a negative effect on mental energy due to their role in overall energy production, as precursors of key cofactors in the citric acid cycle, as well as their role in brain function and neurotransmitter synthesis. Consumption of some of these products may have direct or indirect effects on one or more elements of mental energy.

Conclusion: Large, prospective clinical trials of these products using appropriate, validated instruments designed to measure mental energy may be worthwhile if sufficient evidence exists to justify such trials.

KEYWORDS:

• Cognition
• mood
• motivation
• caffeine
• Panax ginseng
• Ginkgo biloba
• B vitamins

Acknowledgments

Medical writing support was provided by Dennis Stancavish of Peloton Advantage, LLC, an OPEN Health company, and was funded by Pfizer. On August 1, 2019, Pfizer Consumer Healthcare became part of GSK Consumer Healthcare.

Disclosure statement

All the authors gave presentations at a Mental Energy roundtable meeting held at Pfizer offices in New York, New York, on November 30, 2017. A rough outline of the presentations was drafted by medical communications company, Peloton Advantage. All the authors then added substantial intellectual content to the manuscript draft, including several rounds of revisions to ensure accuracy. Peloton Advantage provided formatting and editing assistance. Financial support for both Peloton Advantage and the roundtable meeting was provided by Pfizer. On August 1, 2019, Pfizer Consumer Healthcare became part of GSK Consumer Healthcare.

Additional information

Funding

Medical writing support was provided by Dennis Stancavish of Peloton Advantage, LLC, an OPEN Health company, and was funded by Pfizer. On August 1, 2019, Pfizer Consumer Healthcare became part of GSK Consumer Healthcare.

Notes on contributors

Patrick J. O’Connor

P. J. O’Connor received personal fees and non-financial support from Pfizer for attending the workshop that resulted in this publication, has been primary or co-investigator on grants received from the American Egg Board, California Table Grape Association, Hershey Company, International Life Sciences Institute, McCormick Science Institute, and PepsiCo outside the submitted work, and has served as a consultant to the Kellogg Company and National Cattleman’s Beef Association.

David O. Kennedy

D. O. Kennedy received personal fees from Pfizer for attending the workshop that resulted in this publication and has received grants from Evolva, Frutarom, Mibelle, Nexira, and PepsiCo outside the submitted work.

Stephen Stahl

S. Stahl has served as a consultant to Acadia, Adamas, Alkermes, Allergan, Arbor Pharmaceuticals, AstraZeneca, Avanir, Axovant, Axsome, Biogen, BioMarin, BioPharma, Celgene, Concert, ClearView, DepoMed, Dey, EnVivo, Ferring, Forest, Forum, Genomind, Innovative Science Solutions, Intra-Cellular Therapies, Janssen, Jazz, Lilly, Lundbeck, Merck, Neos, Novartis, Noveida, Orexigen, Otsuka, Pamlab, Perrigo, Pfizer, Pierre Fabre, Reviva, Servier, Shire, Sprout, Sunovion, Taisho, Takeda, Taliaz, Teva, Tonix, Trius, Vanda, and Vifor Pharma; he has been a board member of Genomind and RCT Logic; he has served on speakers bureaus for Acadia, AstraZeneca, Dey Pharma, Eli Lilly, EnVivo, Forum, Genentech, Janssen, Lundbeck, Merck, Otsuka, Pamlab, Pfizer Israel, Servier, Sunovion, and Takeda; and he has received research and/or grant support from Acadia, Alkermes, Arbor Pharmaceuticals, Assurex, AstraZeneca, Avanir, Axovant, Biogen, Braeburn Pharmaceuticals, Bristol-Myers Squibb, Celgene, CeNeRx, Cephalon, Dey, Eli Lilly, EnVivo, Forest, Forum, Genomind, GlaxoSmithKline, Intra-Cellular Therapies, ISSWSH, Janssen, JayMac, Jazz, Lundbeck, Merck, Mylan, Neurocrine, Neuronetics, Novartis, Otsuka, Pamlab, Pfizer, Reviva, Roche, Sepracor, Servier, Shire, Sprout, Sunovion, Takeda, Teva, TMS NeuroHealth Centers, Tonix, Vanda, Valeant, and Wyeth.