Background
The prevalence of age-related chronic diseases including dementia, cardiovascular disease and type II diabetes mellitus is increasing, which is of societal concern. Common pathophysiological characteristics 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 insulin-resistance is associated with cognitive decline. Previously, we have already observed beneficial effects of Aronia melanocarpa extract (AME) on cognitive function. However, studies evaluating the effects of AME on potential underlying mechanisms are still lacking, while effects in a population at increased risk of cognitive impairment are unknown.

Objective
The primary objectives are to investigate effects of AME intake on (regional) brain vascular function and brain insulin-sensitivity in cognitive-control areas, while changes in cognitive function will also be quantified as a secondary objective.

Methods
A randomized, double-blind, placebo-controlled, cross-over trial involving thirty middle-aged and older adults (aged 55-75) will be performed. Participants will receive either 65 mg AME or a placebo for six weeks, separated by a 12 week wash-out. At the end of the intervention period, cerebral blood flow responses before and after intranasal insulin administration will be non-invasively quantified by MRI. Exploratory outcomes include cognitive performance, peripheral vascular function, and other perceivable benefits.

Valorization
This study will advance our understanding why Aronia melanocarpa is beneficial for age-related conditions, including cognitive impairment.

Funding
This study is part of a project conducted within the Health Holland framework, which is partly funded by BioActor BV.