Epidemiological studies have firmly established the health effects of high intakes of fruits and vegetables and in particular in regards to the prevention of cardiovascular diseases. Citrus fruits are the most widely consumed throughout the world, mainly as juice. Citrus fruits are rich in vitamin C but also in various plant micronutrients which are the most abundant polyphenols. Several in vitro studies and animal models suggest that the polyphenols of citrus are involved in the protective effects of citrus vis-à-vis the cardiovascular diseases. However, profits in health associated with taking these polyphenols are unknown and so far no clinical studies have been conducted to determine the contribution of polyphenols of citrus in this protection.
The main objectives of this project are (1) to characterize the effects of single dose and made repeated consumption of orange juice on vascular protection and the immune response and (2) to assess the specific role of polyphenols present in citrus fruits in this protection. To do this the investigators will conduct a clinical study, randomized and crossover, among healthy men 50 to 65 years that are slightly overweight. These volunteers, who continue to follow their usual diet, should consume daily for 4 weeks (1) orange juice or (2) an isocaloric control beverage or (3) the same drink spiked with a dose of polyphenols similar to that given by orange juice.
