A newly released study finds that compounds derived from the spices turmeric and pepper could help prevent breast cancer by limiting the growth of stem cells, the small number of cells that fuel a tumor's growth. Scientists at the University of Michigan Comprehensive Cancer Center have observed that when the dietary compounds curcumin, which is derived from the Indian spice turmeric, and piperine, derived from black peppers, were applied to breast cells in culture, they decreased the number of stem cells while having no effect on normal differentiated cells.