Aronia and cognitive function: Focus on brain insulin-sensitivity and vascular function

Age-related chronic diseases including dementia, cardiovascular disease and type II diabetes mellitus become more and more prevalent, which is of increasing societal concern. Common denominators of these co-morbidities are an impaired vascular function and insulin-resistance. However, little is known about the impact of these risk factors in the brain on cognitive function. This is of interest, since an impaired brain vascular function is an important event preceding the development of impaired cognitive performance and dementia, and brain insulinresistance is associated with cognitive decline. Beneficial effects of Aronia berry (black chokeberry) on cognitive function have already been shown. However, underlying mechanisms have not yet been addressed, while effects of Aronia berry extract are unknown in people at increased risk of cognitive impairment. We hypothesized that supplementation with Aronia berry extract enhances brain vascular function and brain insulin-sensitivity, thereby improving cognitive function.

The primary objectives were to investigate effects of Aronia berry extract intake on brain vascular function and insulin-sensitivity, while we also focused on changes in cognitive function. A randomized, controlled, cross-over trial involving thirty middle-aged and older adults (aged 55-75) was performed. Participants received, in random order, daily an anthocyanin-rich Aronia extract (65 mg) or a placebo for six weeks, separated by a 12 week wash-out. Cerebral blood flow responses before (brain vascular function) and after intranasal insulin administration (brain insulin-sensitivity) were non-invasively quantified by MRI. Overall, no significant effects on whole-brain, gray-matter, cortical and subcortical cerebral blood flow responses were observed after Aronia berry extract supplementation, as compared with placebo. However, evidence was provided for beneficial effects on parameters reflecting executive function. Specifically, an improved retention and manipulation of visuospatial information was found. There were no changes in the psychomotor speed or memory domains.

Overall, this project further advanced our understanding why Aronia berries are beneficial for age-related conditions, including cognitive impairment. Except for its scientific relevance, results will further contribute to other areas: (i) reduction of economic and societal costs; and (ii) opportunities for BioActor to launch and market evidence-based nutritional concepts, to develop applications, and to differentiate from competitors.

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