Green coffee beans offer a host of health benefits without the jittery effects associated with drinking too much caffeine. An extract of green coffee beans has been found to have a stronger antioxidant effect than established antioxidants like green tea and grape seed extract. Other benefits of green coffee bean extract include an increase in the effectiveness of pain killers, especially for migraine medications; a reduction in the risk of diabetes; and assisting the body burn a higher proportion of lipids (fats) compared to carbohydrates, which could help with muscle fatigue for athletes and bodybuilders.
However this is all based on green coffee extract. Green beans cannot be brewed without being roasted first and that means they no longer have the same benefits.