There are many substances that can act as antioxidants; chief among them are vitamins A and C, as well as beta-carotene and manganese. A lack of antioxidant-rich foods can lead to a greater risk of atherosclerosis.
Along with fewer pesticides, this is probably the No. 1 reason folks decide to eat organic. Studies have shown that organic drinks are often higher in vitamin C, iron, magnesium, and phosphorous than their non-organic counterparts.