Wheatgrass is an excellent source of chlorophyll. Chlorophyll increases the production of hemoglobin, a protein in the red blood cells encourages the proper supply of oxygen to body tissues and organs. When hemoglobin levels are dangerously low, your cells are likely to be short on oxygen. Oxygen-deprived cells encourage the growth and spread of cancer cells. Wheatgrass is also high in antioxidants including selenium, laetrile, vitamin C and vitamin E that stall cancer growth by preventing the free radical damage.