Previously, beneficial effects of Aronia Melanocarpa extract (AME) supplementation on cognitive performance has been observed in healthy middle-aged adults. However, underlying mechanisms have not yet been addressed. In addition, effects of AME are unknown in subjects at increased risk of cognitive impairment. It is hypothesized that supplementation with AME enhances (regional) brain vascular function and brain insulin-sensitivity, thereby improving cognitive function of subjects at increased risk of cognitive impairment.

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

The present study is a randomized, double-blind, placebo-controlled, cross-over trial consisting of two study groups and a pre- and post-test day in both study arms.

Inclusion Criteria:

• Men and women, aged between 55-75 years
• BMI between 25-35 kg/m2
• Fasting plasma glucose < 7.0 mmol/L
• Fasting serum total cholesterol < 8.0 mmol/L
• Fasting serum triacylglycerol < 4.5 mmol/L
• Systolic blood pressure < 160 mmHg and diastolic blood pressure < 100 mmHg
• Stable body weight (weight gain or loss < 3 kg in the past three months)
• Willingness to give up being a blood donor from 8 weeks before the start of the study, during the study and for 4 weeks after completion of the study
• No difficult venipuncture as evidenced during the screening visit

Exclusion Criteria:

• Smoking or smoking cessation < 12 months
• Presence of diabetes mellitus
• Active cardiovascular disease like congestive heart failure or cardiovascular event
• Severe medical conditions, including asthma, chronic obstructive pulmonary disease (COPD), kidney failure, auto-inflammatory diseases or rheumatoid arthritis
• Unstable body weight (weight gain or loss > 3 kg in the past three months)
• Use of dietary supplements or medication affecting the main outcomes of the study
• Use of an investigational product within another biomedical intervention trial within the previous month
• Contra-indications for MRI imaging (e.g., pacemaker, surgical clips/material in body, metal splinter in eye, claustrophobia)
• Left-handedness
• Familial hypercholesterolemia
• Abuse of drugs
• More than 3 alcoholic consumptions per day
• Use medication to treat blood pressure, lipid or glucose metabolism