This new study was designed to investigate how the dietary polyphenols curcumin (found in turmeric) and piperine (found in black pepper) influence the self-renewal of normal and malignant breast stem cells. Currently available breast cancer preventives typically reduce the incidence of hormonally driven cancer but are less effective in triple negative breast cancer. According to the cancer stem cell hypothesis, malignancies arise in stem and/or progenitor cells through alteration of self-renewal-related functions, offering another potential pathway to reduce malignancy. Curcumin and piperine, both separately and in combination, were found to decrease the number of stem cells while having no effect on normal differentiated breast cells. The authors conclude that these compounds could be potential cancer preventive agents.

Stem cell therapy could be new approach to reducing breast cancer risk

Numerous other studies have found that curcumin and piperine have chemopreventive properties. This study finds that they may inhibit the growth of stem cells, while not being toxic to normal breast tissue. Stems cells are thought to be important in breast cancer — some researchers believe that they fuel breast tumor growth. Limiting the number of stem cells (including perfectly normal stem cells) could limit the number of cells that can form tumors, according to the authors. This might open a new avenue for reducing breast cancer risk and preventing recurrence.

Current chemotherapies appear to be ineffective against stem cells, which might partially account for why cancer recurs and spreads, sometimes many years later. However, it remains to be seen whether reducing the number of stem cells throughout the body might uncover heretofore unknown critical functions of these cells, for example in regulating aging. A Phase I clinical trial to determine what dose of curcumin or piperine can be tolerated by people is in the planning stages. In the meantime, it makes sense for breast cancer survivors and those at high risk for breast cancer to include turmeric and black pepper in their diets.