Epidemiological studies definitively show that fruit and vegetable consumption is positive for health and more specifically for cardiovascular diseases (CVD) prevention. In France, among fruits, those which are the most frequently consumed are citrus fruits essentially as juices and more specifically as orange juices. However, their health effects have been poorly studied so far. Citrus fruits contain vitamin C associated with various phytomicronutrients i.e. carotenoids (essentially -cryptoxanthin) and polyphenols. Each fruit contains specific compounds: hesperetin in orange, naringenin in grapefruit, eriodyctiol in lemon. Some scientific studies performed either in vitro or in animal models demonstrated properties of these micronutrients which could contribute to a positive health effect of citrus fruits on vascular protection. However data are still missing.

The main goal of this project is to characterize the effect of orange juice consumption on vascular disease risk factors and to evaluate the specific role of their micronutrient compounds (polyphenols and carotenoids) in this protection. To reach this goal, a randomized "cross-over" clinical study will be performed on volunteers presenting a mild hypercholesterolemia. They will consume for 4 weeks an orange juice or a reconstituted drink similar to the orange juice for its composition in carbohydrates, minerals, vitamin C and folates but without phytomicronutrients. The effect of the juice consumption on the vascular function will be monitored exploring lipid abnormalities in plasma, measuring endothelial vasoreactivity (FMD) (Flow Mediated Dilatation), as well as endothelial dysfunction, thrombosis, inflammation and oxidative stress biomarkers in plasma. Comparison of urinary metabolomes after orange juice consumption or that of the reconstituted drink will lead to the identification of the metabolic pathways modulated by the orange juice micronutrients.

Moreover ELISA tests for the two major flavanones from citrus fruits (hesperetin and naringenin) will be developed. They will be used to determine the plasma levels of these molecules in order to analyze the relation "ingested quantity - bioavailable quantity - physiological effect".

The results obtained in this project will allow clarifying citrus fruit effects, and particularly orange juice, in vascular protection.