The importance of variety in your leaf diet
Leaves are the place where plants deal with an array of challenges. The production of their food – photosynthesis – takes place in the leaves. This process involves freeing up oxygen atoms, which are unstable. This instability causes the oxygen grab other molecules (part of the plant) so that the oxygen can stabilize. Even these oxygen-based molecules (referred to as oxidants or free radicals) are not always stable, so the new molecules then try to grab more molecules within the plants. This action damages the cell structures. Plants have evolved to grow an array of anti-oxidants to intercept the oxidants before they cause damage.Oxidants are produced during our own metabolic functions, as well as absorbed/ingested from a variety of sources, such as pesticide, medication, air pollution, etc.
Anti-oxidants remain intact after the leaf has been consumed, and continue to function within your cells. Some anti-oxidants are somewhat effective against many oxidants, while others are target specific and are very effective protection against a particular oxidant.
Which leaf vegetable provides the most effective source of anti-oxidants? This depends on which oxidants you are most concerned. There are hundreds (possibly thousands) of these compounds, and so a definitive, one size fits all approach does not make sense (though the pharmaceutical companies would have you believe otherwise – “nutritionists” have long touted beta carotene as the cure all, but they have little to say about the other hundreds of caratenoids).
Therefore, to my mind, the best way to ensure that you are receiving the optimal quantities of anti-oxidants is to consume the widest variety possible of leaf vegetables. Or to quote Michael Pollan, “eat food…especially leaves”.