Effects of the chronic consumption of fruit- and vegetable-juice shots on oxidative stability of plasma

CVD is a major contributor to mortality and morbidity from degenerative disease, with increases in death recorded each year. Epidemiological studies have shown that a high consumption of fresh fruits and vegetables is associated with a reduction in the level of oxidative stress and CVD risk. Chu and Liu have reported that a daily intake of one serving of fruit and vegetables decreases the risk of CVD by 4%. Since 1989 the US National Academy of Sciences has recommended consumption of at least five portions (400 g) of fruit and vegetables daily, similar recommendations have also been made by the WHO. However, only 13% of males and 15% of females in the UK and 17% of 15 000 Americans surveyed reach this level of intake. Oxidation of LDL has been recognised as an early stage in the development of atherosclerosis, which leads to CVD. An increasing number of studies of the antioxidant effect of phytochemicals in fruits and vegetables, including the retardation of the susceptibility of LDL to oxidation both in vitro and ex vivo, have been reported. A dietary intervention study was conducted to investigate the effects of 5 portions of fruit and vegetables in the form of liquid juice shots on antioxidant status. The effects of consumption of concentrated juice shots for a 6-week period on bioavailability, antioxidant status and risk factors for CVD were investigated. The study was a single-blind randomised controlled cross-over dietary intervention study involving two 6-week intervention periods with juice shots or control (fruit-flavoured squash), with an 8-week washout period. Thirty-nine volunteers (fifteen males, twenty-four females) with an age range of 30–70 years participated in the study. Fasted blood samples and morning spot urine samples were collected before and after each intervention period and biochemical variables were assessed