The daily consumption of a few portions of fruits and vegetables is generally recommended to promote good health due to presence of nutrients and
antioxidants and other phytochemicals. On average people only consume about 3 portions of fruits and vegetables, which is below the recommended min. 5 portions. Previous studies have shown that encapsulated fruit and vegetable juice concentrate increased the proliferation of white blood cells.
The aim of this study was to investigate the influence of intake of commercially available encapsulated fruit and vegetable juice concentrate during 11 weeks on indicators of good health, such as T-cells, cytokine production, DNA damage, antioxidant status and serum levels of carotenoids and ascorbic acid. The capsule contained juice concentrate from acerola, cherry, apple, beet, broccoli, cabbage, carrot, cranberry, kale, orange, peach, papaya, parsley, pineapple, spinach and tomato. The study involved 59 healthy students who received either a fruit and vegetables juice concentrate or a placebo. Law students were chosen for their relative low psychological and physical health compared to other students. Law students are more prone to stress, which impairs the immunity and causes a pro-oxidative state. The fruit and vegetable group showed a slight decrease in illness symptoms. Their numbers of circulating T-cell increased by 30% and DNA damage was reduced by 40%. The inhibition of DNNA damage is probably caused by carotenoids, flavonoids and phenolics. The antioxidant capacity of the plasma increased by 50%, mainly as result of increased plasma levels of ascorbic acid, beta-carotene, lycopene and lutein. Other antioxidants such as zeaxanthin, alfa-carotene, alfa-cryptoxanthin en beta-cryptoxanthin were not changed. The cytokine interferon produced by phorbol-stimulated lymphocytes was also reduced.
The study concluded that the intake of encapsulated fruit and vegetable juice concentrate increased plasma antioxidant capacity, reduced DNA damage and improved the immune function by increasing the number of circulating T-cells.
Source: Nantz MP, Rowe CA, Nieves C and Percival SS. Immunity and antioxidant capacity in humans is enhanced by consumption of a dried, encapsulated fruit and vegetable juice concentrate. Journal of Nutrition. 2006 October;136(10):2606-10