Stick with the best thing, not the next best thing

I keep seeing advertising touting the efficacy of fruit and vegetable extracts such as Juice Plus, promoted by some local practices which call themselves "Integrative Medicine" practices. Juice Plus and similar products purport to lower your cardiovascular and cancer risk and to have research to back them up. The Juice Plus website contains links saying "feel free to look at the research" I decided to do so for my readers to see if there is research supporting its efficacy.

The research I found was all based on what I would call "surrogate markers". That is, no studies demonstrate that anyone actually lives longer through using Juice Plus. All the studies focus on clinical endpoints like flow through certain vessels, or inflammatory medidators in the blood. Most of the trials, also, were not randomized controlled trials, that is, there was no control group in the study, which compared subjects to themselves at "baseline". The problem with this approach is that other changes occur when people are enrolled in studies which may have nothing to do with what is being studied.

So, while these results do not suggest that Juice Plus does any harm, they are certainly not conclusive about its benefits.

The studies do not compare Juice Plus to a diet containing lots of whole fruits and vegetables. This would be the most relevant comparison, and I remain an advocate of eating the whole fruits and vegetables instead in absence of evidence otherwise. Cheaper and more flavorful, too.

I would like to be cautious as I may have missed some literature, so if anyone including the makers of Juice Plus knows of evidence of which I am unaware, please comment on this post!