In a recent study, researchers discovered that consuming a ketone supplement did not enhance cognitive performance in female athletes, despite increasing levels of ketone bodies in the blood. This finding challenges the popular notion that ketone supplements, often associated with the ketogenic diet, could offer a mental edge in high-stress situations. The research was recently published in the Journal of Cognitive Enhancement.
Understanding Ketone Bodies and the Ketogenic Diet
Ketone bodies are compounds produced by the body when it breaks down fat for energy, a process that occurs when glucose—the body’s usual energy source—is scarce. This can happen during fasting, intense exercise, or when following a ketogenic diet, a low-carbohydrate, high-fat diet designed to induce a state of ketosis.
In ketosis, the body shifts from relying on glucose to using ketone bodies as its primary energy source, which has been suggested to offer various health benefits, from weight loss to improved brain function.
The Motivation Behind the Study
The study was inspired by the unique energy demands of the human brain and the potential of ketone bodies as an alternative fuel source during periods of reduced carbohydrate intake or increased physical activity. Previous research suggested that ketone supplements might mimic the effects of the ketogenic diet, offering a shortcut to the cognitive benefits of ketosis without the need to strictly limit carbohydrates.
This possibility has garnered significant interest, particularly among athletes looking for ways to enhance performance both physically and mentally. The researchers aimed to explore whether exogenous ketone supplementation could indeed offer cognitive benefits, specifically in female athletes experiencing mental fatigue.
“My research interests lie in optimizing metabolic health and cognition through nutrition interventions and dietary supplements,” explained study author Hunter S. Waldman, an assistant professor of exercise science at the University of North Alabama. “Many individuals are interested in following the ketogenic diet for brain clarity, but the actual diet is fairly tough to adhere to. I wanted to see if taking a ketone might allow the user the same cognitive clarity without following the actual diet.
How the Study Was Conducted
The study involved twelve female athletes, each participating in rigorous training schedules, who were given a ketone supplement known as ketone monoester (KME) or a placebo in a controlled, blind testing environment. Over several visits to the laboratory, participants underwent a series of cognitive tests before and after consuming the supplements.
These tests were designed to measure various aspects of cognitive performance, including attention, memory, and executive function. The researchers also measured blood levels of ketone bodies, glucose, and lactate to assess the metabolic impact of the ketone supplement.
Findings of the Study
The study’s primary finding is that while ketone supplementation effectively induced ketosis, as evidenced by elevated blood βHB levels and altered glucose and lactate metabolism, it did not confer observable benefits on cognitive performance following mental fatigue. Participants reported feeling more mentally challenged and fatigued during the testing sessions, regardless of whether they had taken the ketone supplement or the placebo.
Interestingly, despite the lack of objective cognitive improvements, participants perceived an improvement in performance under the ketone condition, highlighting a discrepancy between subjective experience and objective cognitive metrics. Some participants were able to correctly guess when they had received the ketone supplement, suggesting that the effects were perceptible in some way, although not in the form of enhanced cognitive function.
These results contribute to the ongoing discussion about the role of exogenous ketones in enhancing cognitive performance, particularly in contexts of physical or mental stress. The study underscores the complexity of metabolic and cognitive responses to ketone supplementation and suggests that benefits observed in some contexts (e.g., physical endurance) may not directly translate to cognitive performance benefits, especially in the absence of a baseline cognitive impairment or significant physical fatigue.
“I would say that in the absence of any serious detriment to cognitive health (e.g., TBI, concussion, dementia), there is a ceiling effect for exactly how much dietary supplements can have an impact,” Waldman told PsyPost. “Ketone supplements were suggested to give a ‘boost’ in IQ for those that take it and like other supplements, I don’t think this is the case. So be skeptical of promises that sound too good to be true.”
Looking ahead, researchers suggest that future studies should explore different contexts and conditions under which ketone supplementation might prove beneficial for cognitive performance. For instance, investigating whether longer durations of supplementation, higher doses, or combinations with other dietary components might yield different results. Additionally, understanding the specific circumstances or types of cognitive tasks where ketone supplementation could offer an advantage remains an area ripe for exploration.
“The biggest limitation to our study was simply that we were unable to induce significant mental fatigue so that even if the supplement does work, it would have been hard to find that in our own study,” Waldman explained. “This is really just the beginning of this research in this area with ketone supplements and I think we have a whole area to pursue, especially how these supplements work when mental fatigue or cognitive decline are absolutely present.”
This research contributes to the ongoing debate about the role of diet and supplements in enhancing brain health and cognitive abilities. While the promise of a simple nutritional supplement to boost brain power is appealing, this study suggests that the reality may be more complex.
“Just remember that supplements are just that – something to supplement your other behavioral choices,” Waldman said. “There’s really nothing that holds a light to a well-rounded diet, exercising regularly, stress management, and good sleep.”
The study, “No Benefit of Ingesting a Low-Dose Ketone Monoester Supplement on Markers of Cognitive Performance in Females,” was authored by Hunter S. Waldman, Eric K. O’Neal, Gaven A. Barker, Craig R. Witt, David A. Lara, Anna K. Huber, Valerie N. Forsythe, Andrew P. Koutnik, Dominic P. D’Agostino, Walter Staiano, and Brendan Egan.