[chris (OP)]

Recently I was in Perth for the Science on the Swan conference where I also delivered a public lecture on healthy living, which included a Q&A session. There were some follow-up questions, which I am answering here; this is one of them:

I went along to Dr Smith's presentation at Perth Town Hall the other day and didn't get a chance to ask my question.  I was hoping to find out if Juice Plus pills that are made from vegetables and also fruit are actually as good for you as advertised/claimed?
 
They are quite expensive to buy so I'm just wondering whether they are worth it!
Many thanks
Juliana

[chris (OP)]

This company (Juice Plus) produce food supplements derived from fruits and vegetables. To their credit, there is an evidence base, some of which they cite on their website, exploring the use of these supplements in various settings.

For instance, one study looking at cold-like illnesses in healthcare workers and published in the Br. Journal of Nutrition showed:

A total of 529 subjects were included into the primary analysis (Juice Plus+®: 263, placebo: 266). The mean age of the participants was 39·9 (sd 10·3) years, and 80 % of the participants were female. The mean number of days with moderate or severe common cold symptoms was 7·6 (95 % CI 6·5, 8·8) in the Juice Plus+® group and 9·5 (8·4, 10·6) in the placebo group (P = 0·023).
 
Looks interesting, but then look at the line that comes next:

The mean number of total days with any common cold symptoms was similar in the Juice Plus+® and in the placebo groups (29·4 (25·8, 33·0) v. 30·7 (27·1, 34·3), P = 0·616).

So people taking the supplements might have got ill just as often as people who were not taking the real pills, although they might have had more severe symptoms on the placebo.

It's certainly true that a healthy diet is critical to having the best health outcomes. But I'm not completely convinced that these manufacturers are truly comparing apples with apples, to take a food analogy. The appropriate experiment is to put a group of people onto a healthy diet that supplies the same micronutrients in the context of normal food and then switch the same subjects onto the pills and their own "normal" diet. I suspect that a healthy diet would achieve all the same metabolic ends as these pills but at a fraction of the cost. But, if anyone does have clinical evidence to the contrary, please let me know and I'll willingly eat humble pie, although not too much of it, because that could be unhealthy...