Antioxidants: Food or Supplement?

I read an article from my nutrition textbook entitled "Antioxidants: Food or Supplements?" I found this nutrition debate to be quite interesting. When I hear the term "antioxidants", I immediately think of the health benefits like reducing heart disease. It never occurred to me that antioxidants can be potentially harmful. After reading the article, I was intrigued to know what other current sources thought about whether antioxidants help or harm. From an informative writing piece on ScientificAmerican.com, I learned a bit more in depth about the functions of antioxidants. Oxidation in the body is a process that can increase cholesterol to stick in the arteries which will increase risk in heart blockage and other problems. Antioxidants theoretically aid in keeping oxidation in check by slowing down the reaction.
But the fact remains, there have been several experiments where antioxidants have done more damage than healing. According to the textbook and website article, the problem lies within supplements not natural food sources high in antioxidants. Both articles indicate a few explanations. Perhaps the supplements are being taken in higher doses than recommended. Also typically, when health conscious people eat foods that naturally contain antioxidants, those same people eat other health foods and are active participants in exercise. Another possible explanation is that many different types of oxidation stress exists and supplements only associates with some of those stresses.
We learned in my nutrition class, moderation is one of the key terms for nutrition. Antioxidants are a great example. Any type of food can be too much of a "good thing". I believe like everything else, antioxidants should be consumed in reasonable amounts, nobody should gorge themselves with pomegranates to obtain lots of antioxidants. But I'm sure antioxidants are beneficial to some extent. I'm anxious to hear from medical resources in the future for conclusive statements about the antioxidant controversy.