Effect of an Apple Polyphenol Extract on Brachial Artery Flow-mediated Vasodilatory Function

The aim of this single centre, repeated-dose, double-blind, placebo-controlled, crossover study is to test the hypothesis that an orally ingested apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers improves brachial artery endothelium-dependent vasodilation function (FMD) in volunteer subjects with borderline hypertension. FMD and endothelium-independent nitrate-mediated vasodilatation (NMD) of the left brachial artery will be investigated with ultrasonography at the start and end of both treatment periods. Biomarkers of vascular function and epicatechin (and metabolite) concentrations will be determined from blood samples taken at the start and end of both treatment periods. Diet diary data will be collected for the evaluation of the possible effects of diet on the study results. Adverse events data will be collected throughout the study. Safety laboratory determinations will be performed at the last visit of both treatment periods.

Inclusion criteria

• Borderline hypertension
• Otherwise healthy
• Aged 40-65 years (inclusive)
• Not consuming high amounts (over 20 mg daily) of flavonoids

Exclusion criteria

• BMI >32 kg/m2
• Total serum cholesterol ≥ 8 mmol/l
• Any abnormal safety laboratory parameter or abnormal finding in ECG evaluated to be clinically significant
• Coronary artery disease
• Pregnancy or lactating
• Alcohol abuse as evaluated by medical history
• Regular smoking/using nicotine products
• Diabetes mellitus
• Apple allergy
• Use of lipid lowering medications
• Regular use of any medication that is known or believed to affect endothelial function or blood vessel constriction
• Any other condition or medication that in the opinion of the investigator would interfere with the evaluation of the study results or constitute a health risk for the subject
• High consumption of vitamin products, herbal remedies or products containing flavonoids