Bioavailability and nutritional effects of phyochemicals

• Main Author: Niwat, Chutamat
• Published: University of Reading 2009
• Subjects: 572.2
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553070

Recent epidemiological studies have shown that consuming a diet rich in fruits and vegetables is associated with a reduced risk of cardiovascular disease and cancer. The hypothesis of this thesis is that increasing the consumption of fruits and vegetables in the form of soups and drinks will increase the plasma phytochemical concentrations, antioxidant status and improve the oxidative stability of LDL ex vivo. The thesis describes two intervention studies. The first was a chronic study, which investigated the bioavailability of carotenoids and beneficial effects of carotenoid-rich foods in the Carotenoid-Rich Soup and Juice Study (CARS). The second study was an acute intervention, which investigated the effects of fruit and vegetable puree-based drinks (FVPD) in the Flavonoid Kinetics Study (FLaKS). The studies showed that the consumption of fruit and vegetables in the form of soups and puree drink, equivalent to five portions of fruits and vegetables, increased plasma phytochemicals in a chronic intervention, and increased plasma phytochemicals and plasma antioxidant capacity in the acute intervention. However, there was no significant effect of the interventions on the resistance of LDL to copper-induced oxidation. The ability of caffeic acid and rutin to bind to LDL and to affect the susceptibility of LDL to oxidation was studied. The current study showed that the polyphenol compounds did not bind to LDL or increase the oxidative stability, except when added rutin was present. In conclusion, the thesis showed that increasing the consumption of fruits and vegetables in the form of soups and drinks, equivalent to five portions of fruits and vegetables, will increase the plasma phytochemical concentrations, and postprandial antioxidant capacity. Possible effects on vascular reactivity need further study.