Several indicators of oxidative stress, immunity, and illness improved in trained men consuming an encapsulated juice powder concentrate for 28 weeks

Lamprecht M, Oettl K, Schwaberger G, Hofmann P, Greilberger JF; Dec. 2007


The aim of this study was to determine whether a commercially available encapsulated fruit, vegetable and berry juice powder concentrate (FVB) could reduce exercise-induced oxidative stress, impact markers of immune function, and reduce duty days lost to illness in fit police officers.  


Researchers randomly assigned 41 trained, healthy, non-smoking men (average age 34) to take either 6 capsules daily of FVB (Juice Plus+®) or placebo for 28 weeks while following their usual diet and training regimen. Blood samples were analyzed for protein carbonyls (a marker of oxidative stress) and TNF-alpha and IL-6 (serum markers of immune function) at baseline and at weeks 4, 8, 16, and 28. The group physician also documented duty days lost to illness.  


During the study, the officers’ hours increased, which would be expected to cause an increase in oxidative stress. Accordingly, the protein carbonyls (PC) levels of men in the placebo group rose over time. However, the PC levels of men in the FVB group dropped below baseline levels, indicating that FVB effectively counteracted oxidative stress related to increased chronical stress and workload.  

In addition, during the final 20 weeks of the study, the men taking the juice powder concentrate showed a trend for fewer duty days lost due to illness. At weeks 16 and 28, TNF-alpha levels were also significantly lower among those taking FVB, indicating improved immune status. Plasma IL-6 concentrations were highly variable and did not change in either group. 


In conclusion, the groups did not differ in relation to IL-6, SOD, and GPx. However, the JPC [juice powder concentrate] group showed positive changes in CP and TNF-alpha concentrations and a trend toward fewer duty days lost to illness compared with the placebo group.  

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