I'd hate to think the four cups of green tea I drink every weekday* have been for naught. However, the "relation to diet" section of the wikipedia page for antioxidants posits that despite recent enthusiasm for antioxidant-rich diets, there's no science to back up the claims.
Please check out the link for more, but here's a couple excerpts:
This idea [antioxidant compounds might lower risk against several diseases] has been tested in a limited manner in clinical trials and does not seem to be true, as antioxidant supplements have no clear effect on the risk of chronic diseases such as cancer and heart disease. This suggests that these health benefits come from other substances in fruits and vegetables (possibly dietary fiber) or come from a complex mix of compounds.I know it's poor form to cite Wikipedia, but the article itself links to many offsite articles.antioxidant supplements do not appear to increase life expectancy in humans.
And I know they're talking about supplementation, but the best they can suggest in the above quote is that perhaps benefits come from "a complex mix of compounds."
So yes eat your varied diet, of course, but do you need to bother seeking out antioxidant superfoods? It's easy to say just don't worry about it and make sure you have a varied diet - but I'd like to know if there's actual strong science to prove claims specifically about antioxidants themselves one way or another.
With all the marketing around antioxidant rich diets, it definitely affects a lot of our food choices. I know whenever I eat blueberries the term "antioxidant rich!" is in the back of my mind. If it is dietary fiber instead of antioxidants, I think I still get plenty of it from whole (not juiced) vegetables.
* I make green tea, iced, for hydration to drink while bike commuting. It's not a wonderful flavor, so I'd just as soon not bother making tea every night if there's no health benefit.