Fresh cut Cabbage Collards/ Morris Heading Collards. Studies have shown that eating cruciferous vegetables like collard greens may lower the risk of developing certain types of cancer, including breast, prostate, ovarian, lung, bladder, and colon cancer. Collard greens are high in potassium and dietary fiber, which can help improve HDL cholesterol levels and lower LDL cholesterol levels. This can help prevent plaque and fatty deposits in the heart, which can improve heart health. Collard greens are a good source of calcium and vitamin K, which help build and strengthen bones. One cup of cooked collard greens contains about 21% of the daily recommended amount of calcium.