If you prefer a light roast coffee to a dark, bold blend, your choice of joe may be better for your health.
A study in the Journal of Medicinal Food found the lighter the roast of coffee the higher the concentration of the antioxidant chlorogenic acid.
Researchers also exposed the extract of each roast of coffee to human cell cultures. The lighter roasts with higher does of antioxidants better prevented cell damage.
The reason that dark varieties have a lower antioxidant content is because the coffee beans are roasted more, meaning they're more exposed to air for longer periods and likely at higher temperatures. All of those things contribute to oxidation and depletion of antioxidant elements.