Supplementation with mixed fruit and vegetable juice concentrates increased serum antioxidants and folate in healthy adults

Kiefer I, Prock P, Lawrence C, Wise J, Bieger W, Bayer P, Rathmanner T, Kunze M, Rieder A; Jun. 2004


Observational studies have shown that low levels of antioxidant nutrients found in fruits and vegetables are linked to higher risk of cardiovascular disease, metabolic disorders, and cancer. 


The aim of this study was to collect information on the dietary habits of a group of healthy, middle-aged men and women and to investigate whether an encapsulated fruit and vegetable juice powder concentrate (FV) could raise plasma levels of various antioxidant micronutrients and lower oxidative stress. 


For this randomized, double-blind, placebo-controlled, crossover trial, a total of 59 healthy volunteers, ages 40-60, were divided into two groups. For the first 7 weeks, Group 1 took a fruit and vegetable juice powder concentrate (Juice Plus+®), 2 capsules of the Fruit Blend were taken with breakfast and 2 capsules of the Vegetable Blend were taken with lunch or dinner, while Group 2 took placebo pills. For the next 7 weeks, the regimen switched: Group 1 took the placebo, while Group 2 took FV. Participants were asked to continue with their usual diets. Blood and urine samples were collected at baseline, week 7, and week 14. Additionally, participants completed food frequency questionnaires to assess their fruit and vegetable consumption.  


None of the participants ate the minimum recommended 5 servings of fruits and vegetables per day. Blood analysis revealed that the encapsulated fruit and vegetable juice powder concentrate significantly increased levels of the antioxidant micronutrients beta-carotene, vitamin C, vitamin E, and selenium — as well as folate — compared to placebo. The urinary measure used to assess oxidative stress levels, 8- oxo-7,8-dihydro-2‘-deoxyguanosine (8-oxodGuo), revealed no difference between the two groups.  


“Supplementation, in general, proved to be effective for raising plasma levels of all the nutrients studied... A supplement derived from dehydrated natural mixed fruit and vegetable juices may be beneficial in the prevention of disease and may offer synergistic benefits from nutrient combinations.”

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