Acute effects of combined Bacopa, American ginseng and whole coffee fruit on working memory and cerebral haemodynamic response of the prefrontal cortex: a double-blind, placebo-controlled study

ABSTRACT

Objective: This study assessed whether a multi-ingredient herbal supplement containing Bacopa monniera (BM), Panax quinquefolius ginseng (PQ) and whole coffee fruit extract (WCFE) could enhance cognitive performance and cerebral-cortical activation during tasks of working memory and attention.

Method: In a randomised, double-blind, placebo-controlled, between-group study, 40 healthy adults between 18–60 years (M = 34.46 SD = 12.95) completed tasks of working memory and attention at baseline and 45 min post active or placebo supplement consumption. During the cognitive testing, changes in hemodynamic response in the prefrontal cortex (PFC) were continuously measured using functional near-infrared spectroscopy (fNIRS).

Results: Working memory task performance on the N-back task was significantly improved following active supplement consumption compared to placebo in terms of accuracy (p < .01) and response time (p < .05). Improved performance was associated with a reduction of PFC activation (p < .001) related to effortful mental demand, reflecting increased neural efficiency concomitant with improved cognitive performance. The effects were independent of background demographics variables and changes in blood glucose response and mood.

Discussion: This is the first report of acute effects on cognitive performance in healthy adults following intake of a combined, multi-ingredient herbal supplement with concomitant changes in cerebral haemodynamic response. The potential synergistic effects of polyphenolic compounds on neurocognitive function and fNIRS use in nutritional intervention studies, poses a significant increase in the capacity to understand the effects of dietary compounds on the brain.

KEYWORDS:

• Nutrition
• cognition
• polyphenols
• working memory
• mood
• herbal extracts
• fNIRS
• intervention

Acknowledgement

This is to acknowledge that none of the authors have any financial interest or benefit from the production and publication of this research.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by funding from USANA Health Sciences Inc. with an in-kind contribution from Central Queensland University and Nanyang Technological University, Singapore. There was no direct involvement of the funder in the design, implementation, analysis and manuscript preparation.

Notes on contributors

Talitha Best

Talitha Best is an Associate Professor in Psychology and practicing Clinical Psychologist with research and clinical interests in cognitive neuroscience and nutritional applications to support brain and mind health across normal ageing. Talitha's research seeks to promote the translation of research findings into approaches for promoting brain function, behaviour, mood and cognitive performance.

Chantelle Clarke

Chantelle Clarke is a research assistant and Ph.D. candidate investigating the interactions between food choices and dietary patterns for physiological, cognitive, and psychosocial health and wellbeing. Chantelle's research interests include understanding the role of consumer characteristics in food choices and dietary pattern uptake, cognitive, behaviour and lifestyle.

Nathan Nuzum

Nathan Nuzum is a Ph.D. candidate investigating the relationships between cognition, neuroplasticity and gut bacteria across ageing and in Parkinson's disease. Nathan's wider research interests involve brain stimulation, cognition, physical activity and exercise and brain health across normal ageing and in neurodegenerative diseases.

Wei-Peng Teo

Dr Wei-Peng Teo is an exercise neuroscientist who specializes in the use of non-invasive brain stimulation and neuroimaging techniques to measure neural adaptations and cognitive functioning to exercise, lifestyle and nutritional interventions. His current research focuses on understanding typical and atypical neurodevelopmental trajectories in children, with a special focus on the relationship between cognitive functioning and motor abilities in children.