A mixed fruit and vegetable concentrate increases plasma antioxidant vitamins and folate and lowers plasma homocysteine in men

Samman S, Sivarajah G, Man JC, Ahmad ZI, Petocz P, Caterson ID; Jul. 2003


The aim of this study was to evaluate the bioavailability of selected carotenoids and vitamins from a fruit and vegetable juice powder concentrate (FV) and their impact on antioxidant status, homocysteine, plasma lipids, and insulin resistance in men.


Thirty-two healthy men between the ages of 18 and 50 completed the randomized, double-blind, placebo-controlled, crossover clinical trial. Forty percent of them were smokers. Participants took either an encapsulated fruit and vegetable juice powder concentrate (Juice Plus+®, 2 capsules of the Fruit Blend and 2 capsules of the Vegetable Blend) or placebo for 6 weeks, followed by a 3-week wash-out phase. For the next 6 weeks, the groups switched. Blood samples were collected at baseline, day 21, and after 6 weeks of each intervention period. Coronary heart disease risk was assessed by measuring concentrations of homocysteine, lipids, lipoproteins, glucose, and insulin.


Compared to placebo, FV increased the concentrations of antioxidants in the blood significantly. Levels of β-carotene rose 4-fold, while concentrations of vitamin C and vitamin E (alpha tocopherol) increased 32% and 9% respectively. In addition, blood levels of folate rose by 79% and homocysteine levels decreased by 8%. There was a positive association between plasma levels of vitamin C and resistance of LDL to oxidation. Plasma glucose, insulin, and lipid concentrations were unaffected. Results were similar among smokers and non-smokers.


In conclusion, supplementation with a mixed fruit and vegetable concentrate increases plasma ascorbic acid, β-carotene and folate, and lowers plasma homocysteine.

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